Disclosure of Invention
The invention aims to solve the problems in the prior art, and provides a radioactive three-dimensional nanostructure photovoltaic electrochemical cell which can effectively avoid the problems of self-absorption, partial reflection, small specific surface area and the like of a solid radiation source, and an electrolyte can effectively absorb the ionizing radiation kinetic energy of radiation particles, so that the radiation damage to a semiconductor structure is effectively eliminated.
In order to achieve the purpose, the invention adopts the following technical scheme:
a radioactive three-dimensional nanostructure photovoltaic electrochemical cell comprises an anode, a cathode and an electrolyte, wherein the anode consists of a substrate electrode and a semiconductor three-dimensional nanostructure integrated on the surface of the substrate electrode, the electrolyte is filled between the anode and the cathode, and the electrolyte is filled in the semiconductor three-dimensional nanostructure; at least one of the substrate electrode, the semiconductor three-dimensional nanostructure and the cathode has radioactivity, and the substrate electrode can adopt an irradiated substrate electrode in which one or more stable elements are replaced by radioactive isotopes of the same type; the semiconductor three-dimensional nano structure can adopt a radiation semiconductor structure in which one or more stable elements are replaced by the same type of radioactive isotope; the cathode can adopt an irradiated cathode in which one or more stable elements are replaced by the same type of radioactive isotope; the radiation produced by the radioisotope includes at least one of alpha particles and beta particles, the radioisotope has a half-life of 5 years or more, and the mean energy of the radiation particles is not higher than 250 keV.
In the present invention, the spotlighted electrode has a metallic characteristic, which forms a schottky contact or an ohmic contact with the semiconductor and also with the cathode on topOne of the electrode or substrate electrode is connected, e.g. tritiated titanium electrode (Ti)3H4)、63Ni foil electrode, based on14Carbon electrode of C, Si14C-electrodes and combinations thereof.
The radiation semiconductor is formed by isotopic transformation of semiconductor material, and the metal and non-metal elements in the semiconductor and the isotope form stable chemical bond (such as3H-Ti bond,14A C-Si bond,63Ni-O bonds) resulting in the recombination of the radioisotope with the semiconductor material, such as tritiated TiO2、Na36Cl、40KCl、60CoSO4、63NiO、63NiCl2、90SrCl2、90Sr(NO3)2、Na129I and carbon-14-based carbonates, hydrogen and carbon in the constituent elements of the compounds3H and14c substituted organic or inorganic compounds.
The electrolyte between the anode and the cathode can be a radioactive electrolyte, the radioactivity of which comes from one or more stable elements in the electrolyte being replaced by the same type of radioactive isotope. The radioactive electrolyte has high electrochemical stability and electrochemical window (greater than 4V), high ionic conductivity, low viscosity, and good solubility for most inorganic salts and organic species.
The radioisotope is selected from tritium (A), (B), (C), (3H) Carbon-14 (C)14C) Chlorine-36 (36Cl), potassium-40 (40K) Cobalt-60 (C)60Co), nickel-63 (63Ni), strontium-90: (90Sr)、99Tc、129I、133Ba、137Cs、147Pm、148Gd、151Sm、152Eu、204Tl、210Pb、210Po、235U、241Am and244cm, or one or more isotopes of Cm.
The radioactive electrolyte comprises a radioactive liquid electrolyte, a radioactive quasi-solid electrolyte and a radioactive solid electrolyte.
The radioactive liquid electrolyte comprises a solvent, a solute and an additive; the solvent comprises an inorganic solvent, an organic solvent or a mixed solvent of the inorganic solvent and the organic solvent; the solute comprises a solvent-soluble redox complex and an oxidized/reduced ion pair; the solvent and solute individually or together comprise one or more elemental radioisotopes or isotopic compounds; the additive adopts a functional compound which reduces the recombination probability of electron-hole pairs and further improves the output power of the photovoltaic electrochemistry, and the functional compound comprises at least one of potassium chloride, iodinated imidazole salt and pyridinium.
The isotopic compound comprises tritiated water (3H2O)、Na36Cl、40KCl、60CoSO4、63NiO、63NiCl、90SrCl2、90Sr(NO3)2、Na129The hydrogen and carbon in the component elements of the carbonate and the compound based on the carbon-14 can be replaced by3H and14c substituted organic or inorganic compound; the isotope simple substance comprises14C graphene, carbon nanotube, graphite, and iodine-129: (129I2)。
The inorganic solvent comprises water, and the organic solvent comprises at least one of nitrile, alcohol, ether and ester; the redox ion pairs include metallic redox couples and inorganic non-metallic redox couples, wherein the metallic redox couple includes a zinc complex (Zn)+/Zn2+) Copper complex (Cu)+/Cu2+) Cobalt complex (Co)+/Co2+) Cadmium complex (Cd)+/Cd2+) Thallium complex (Tl)0/Tl+) Lead complex (Pb)+/Pb2+) Nickel complex (Ni)+/Ni2+) Chromium complex (Cr)+/Cr3 +) Iron complex (Fe)2+/Fe3+) Manganese complex (Mn)3+/Mn4+) (ii) a The inorganic non-metal redox couple comprises an iodine complex (I)-/I3 -) Sulfur complex (S)2-/Sx 2-) Bromine, bromineComplex (Br)-/Br3 -) Thiocyanide complexes (SCN)-/(SCN)2) Selenium cyanide complex (SeCN)-/(SeCN)2) (ii) a The redox complex includes tetramethylpiperidine nitroxide (TEMPO), disulfide/thiol, and is present in the solvent of the radioactive electrolyte at a concentration of about 0.1 μ M to about 10M.
The radioactive quasi-solid electrolyte forms a three-dimensional network structure by adding a curing agent into a liquid electrolyte, so that the liquid electrolyte is cured to form the quasi-solid electrolyte; at least one of the liquid electrolyte and the curing agent contains a radioisotope; the curing agent comprises a small molecule gelling agent, inorganic nanoparticles and a polymer; the small molecule gelling agent comprises amino acids, biphenyl and saccharide derivatives; the inorganic nanoparticles comprise carbon nanotubes, graphene and nano TiO2Nano SiO2Carbon nanoparticles; the polymer comprises polyacrylonitrile, polyoxyethylene ether, polyvinyl alcohol, polysiloxane, polymethacrylate and polyvinylidene fluoride.
The radioactive solid electrolyte comprises an inorganic p-type semiconductor structure containing radioactive isotopes, an organic hole transport material and a polymer; the inorganic p-type semiconductor structure comprises CuI, CuSCN, NiO and CSSnI3At least one of NiMgLiO and NiMgLiO; the organic hole transport material comprises at least one of spiro-OMeTAD, PEDOT, PTAA, (P3HT), MeO-TPD, polypyrrole, polyaniline and polydiacetylene; the polymer comprises at least one of polyethylene oxide and polypropylene oxide.
The cathode can adopt a three-dimensional nano structure with a large specific surface area, and the radioactive electrolyte can be filled in holes, holes and gaps of the three-dimensional nano structure and form a hydrophilic surface with the surfaces of the anode and the cathode.
The semiconductor three-dimensional nanostructure comprises a nano-array structure of nanoparticles, nanowires, nano-pillars, nanotubes, nano-forests, nano-flowers, nano-sheets (nano-belts), nano-springs, nano-rings, nano-combs, nano-nails (nano-needles), nano-cages, nano-tetrapods, tower-like nanostructures, disc-like nanostructures, star-like nanostructures, branched nanostructures, hollow nano-microspheres, and combinations thereof, preferably a nano-pillar and nanotube array structure.
The distance between the semiconductor three-dimensional nano structure and the cathode is 0-5 mm. When the distance between the semiconductor and the cathode is zero, the semiconductor is in close contact with the cathode to form a semiconductor-conductor Schottky heterojunction interface; when the distance between the two is not zero, the radioactive electrolyte can be stored in the three-dimensional nanostructure and also can be stored in the gap between the anode and the cathode, and the radioactive electrolyte and the semiconductor are contacted to form a solid-liquid heterojunction, which is beneficial to the effective separation of electron-hole pairs.
The cathode has good conductivity and a high work function, and may be selected from metal electrodes (e.g., Pt, Au, Pd, Fe, Co, Cr, Ni, Ag, Ti, Al, Ru, Cu, Mo, Ir, Rh, and alloys thereof), doped semiconductor electrodes (e.g., ITO, FTO, AZO), graphite electrodes, graphene electrodes, carbon nanotube electrodes, conductive polymer electrodes, conductive paste electrodes, and combinations thereof. The substrate electrode and the cathode electrode may be of the same material or of different materials. When different conductive materials are used, due to the difference of work functions of the materials, a contact potential difference can be formed between an upper polar plate and a lower polar plate of the wide bandgap semiconductor one-dimensional nanostructure, and a strong polar plate electric field is favorable for separation of electron-hole pairs.
The substrate electrode is used as a substrate of the semiconductor three-dimensional nanostructure, has good conductivity and forms ohmic contact with the semiconductor three-dimensional nanostructure; the substrate electrode can be selected from metal electrodes (such as Al, Ag, Ti, Ni, Cr, Sn, Pt, Cu, Mo and alloys thereof), doped semiconductor electrodes (such as ITO, FTO, AZO), graphite electrodes, graphene electrodes, carbon nanotube electrodes, conductive polymer electrodes, conductive paste electrodes and combinations thereof, and can be planar, cylindrical, spherical and spherical in shape.
The semiconductor is a single substance or compound semiconductor in a single crystal or polycrystal state, and can be selected from silicon, germanium, diamond, titanium dioxide, zinc oxide, zirconium dioxide, cadmium oxide, niobium pentoxide, cerium oxide, gallium trioxide, tin dioxide, tungsten trioxide, silicon carbide, gallium nitride, indium gallium nitride, gallium indium nitride, gallium phosphide, indium nitride, aluminum phosphide, aluminum arsenide, molybdenum disulfide, cadmium sulfide, zinc sulfide, magnesium sulfide, zinc selenide, magnesium selenide and a combination thereof, preferably a wide bandgap semiconductor structure, and the thickness of the semiconductor is between 10nm and 500 mu m.
To improve the energy conversion efficiency of a photovoltaic electrochemical cell, the semiconductor can improve the generation and transport efficiency of carriers through a material modification process. The material modification process comprises high temperature reduction annealing under inert gas (such as argon, nitrogen, helium, hydrogen and combination thereof); ion implantation doping, high temperature diffusion doping, chemical reaction doping of metals (such as Zn, Fe, Mn, In, Sn, Pt, Au, and combinations thereof) or non-metallic elements (such as N, C, F, P and combinations thereof).
The semiconductor structure is formed into a heterojunction composite structure by attaching a nano material on the surface of the semiconductor structure through physical or chemical surface modification and doping modification, wherein the modification material is selected from carbon-based low-dimensional conductive materials (such as carbon quantum dots, carbon nano tubes, graphene, fullerene and a combination thereof), auxiliary semiconductors (such as cadmium sulfide, zinc sulfide, molybdenum sulfide, nickel oxide, cuprous oxide, zirconium dioxide, magnesium oxide, copper thiocyanate and a combination thereof), metal nanoparticles (such as gold particles, platinum particles, nickel particles and a combination thereof), and conductive polymers (such as polypyrrole, polyaniline and a combination thereof).
The invention is isolated from the outside by the sealing protection structure, and the sealing protection structure has higher rigidity, hardness and radiation resistance, and has an internal and external electric connection structure, so that the photovoltaic electrochemical cell can be completely isolated from the outside.
The invention can realize multi-group unit multilayer stacking cascade packaging in a series or parallel mode. And taking the substrate electrode integrated with the semiconductor three-dimensional nano structure as a unit, and stacking and packaging a plurality of groups of units in sequence. The uppermost and lowermost electrodes are defined as collecting positive and negative electrodes, and the series connection of the battery pack can be realized; the odd electrodes are connected as collecting anodes, the even electrodes are connected as collecting cathodes, parallel connection of the battery pack is achieved, large unit volume output power is achieved, and the battery pack has the advantages of being small in size and high in energy density.
The battery duty cycle process of the present invention is illustrated as follows: the high-energy rays generated by an isotope radiation source act with the three-dimensional nanostructure of the anode semiconductor, so that the anode semiconductor generates a large number of electron-hole pairs, the electron-hole pairs are separated under the action of a built-in electric field formed by the heterojunction of the anode semiconductor, the holes and the electrolyte undergo oxidation reaction and migrate to the cathode, the electrons are transferred to the cathode through an external circuit and undergo reduction reaction with the electrolyte, and the redox products generated after the oxidation-reduction reaction can circularly and repeatedly react with the electrons and the holes, thereby forming a complete electrochemical reaction system.
In the invention, the radioactive electrolyte is filled in the three-dimensional nanostructure space of the anode semiconductor, is fully contacted with the anode and the cathode and does not react at all, and is modified and modified on the surface of the anode semiconductor material by a physical or chemical method to form a heterojunction composite structure. The radiation particles generated by the radioactive electrolyte excite electrons on the valence band of the anode semiconductor structure to jump to a conduction band and generate a large number of electron-hole pairs, separation is realized under the action of an internal electric field, electrons flow from the semiconductor structure to a cathode/electrolyte interface through an external circuit to perform reduction reaction with oxidized substances in the electrolyte, holes perform oxidation reaction with the reduced substances in the electrolyte at the anode/electrolyte interface, and oxidation-reduction products generated after the oxidation-reduction reaction can circularly reciprocate to react with the electrons and the holes, so that a complete electrochemical reaction system is formed.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
the device units of the traditional isotope battery are mostly in a solid direct contact mode, on one hand, the radiation source can cause inevitable radiation damage to a semiconductor structure, and the service life of the device can be reduced; on the other hand, the recombination rate of interface charges is high, and electron-hole pairs generated under the photovoltaic effect cannot be effectively separated, so that the energy conversion efficiency of the device is reduced. In the invention, the radioactivity of the radiation electrode and the radiation semiconductor is from one or more stable elements in the electrode or the three-dimensional nanostructure of the semiconductor to be replaced by the radioactive isotopes of the same type, and the electrolyte is added between the anode and the cathode, so that the existence of the electrolyte can effectively absorb the ionizing radiation kinetic energy of radiation particles, thereby effectively eliminating the radiation damage to the three-dimensional nanostructure of the semiconductor, and a contact interface is formed among the cathode, the electrolyte and the anode, so that the contact interface has a high potential barrier, a large number of electron-hole pairs generated under the radiation effect can be effectively separated, the carrier recombination rate is reduced, and the energy conversion efficiency of the radiation electrochemical cell is effectively improved.
The invention provides a three-dimensional nanostructure photovoltaic electrochemical cell based on a wide-bandgap semiconductor and an electrolyte, wherein the three-dimensional nanostructure photovoltaic electrochemical cell is used as an energy conversion material of the photovoltaic electrochemical cell, so that the contact area between an isotope radiation source and the energy conversion material can be increased, and the absorptivity of radiation particles can be enhanced. In addition, the electrolyte filled in the semiconductor three-dimensional nano-space structure can effectively absorb the ionizing radiation kinetic energy of radiation particles, so that the radiation damage to the semiconductor three-dimensional nano-space structure is effectively eliminated, the problem that the utilization efficiency of a radiation source is reduced due to the low energy self-absorption effect, scattering effect and coupling efficiency of the radiation source is solved, and the conversion efficiency and the unit volume output power of the isotope battery are greatly improved.
According to the invention, the tritiated metal electrode and the three-dimensional nanostructure semiconductor form Schottky or ohmic contact, so that electron-hole pairs generated by isotope radiation beta particles can be effectively separated and transmitted, the carrier recombination rate is reduced, and the energy conversion efficiency of the tritium-volt battery is effectively improved.
The anode adopts a semiconductor three-dimensional nano structure with a large specific surface area, and radioactive electrolyte can be filled in the space of the semiconductor three-dimensional nano structure and is tightly contacted with the space of the semiconductor three-dimensional nano structure to form a plurality of miniature electrolytic cells, so that stacking integration of a plurality of groups of units is facilitated, and short-circuit current, open-circuit voltage and energy conversion efficiency of the photovoltaic electrochemical cell are further improved.
In order to further improve the energy conversion efficiency of the battery, the surface of the semiconductor three-dimensional nanostructure is modified or doped by a physical or chemical method. For example, carbon-based low-dimensional conductive materials, auxiliary semiconductors, metal nanoparticles and conductive polymers are adhered to the surface of the one-dimensional semiconductor nanomaterial. The battery performance can be greatly improved by compounding zirconium dioxide nano particles on the surface of a titanium dioxide nano rod array and then compounding a single-wall carbon nano tube serving as an electrocatalyst with a semiconductor structure, wherein a heterojunction formed by titanium dioxide/zirconium dioxide can effectively promote the rapid separation and transmission of electron-hole pairs, the single-wall carbon nano tube not only has a large specific surface area to provide rich redox active sites, so that redox substances can be rapidly transferred in simple porous geometric shapes to enhance the redox reaction, but also has ultrahigh electronic conductivity and ultralow reduction potential, so that the loss of the potential can be reduced to the greatest extent, the ion transmission and the reduction reaction of oxides are promoted, the rapid regeneration of electrolyte molecules or ions is realized, and the energy conversion efficiency of the battery is improved. Therefore, the radioactive three-dimensional nanostructure photovoltaic electrochemical cell can further improve the energy conversion efficiency of the isotope battery, and has a positive promoting effect on the progress of the whole isotope battery field and the development of related industries.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.
Example 1
The structure of the three-dimensional nanostructure photovoltaic electrochemical cell is shown in figure 1, and the cell structure comprises: 1-FTO substrate electrode, 2-TiO2A nanorod array, 3-electrolyte, a 5-tritiated titanium cathode and a 4-sealed cavity.
In the embodiment, the titanium dioxide nanorod array film is formed by arranging multiple highly ordered quadrangular-prism-shaped nanorods; the electrolyte is Fe3+/Fe2+Inorganic aqueous solution of redox couple, and the inorganic aqueous solution is filled in the three-dimensional nanometer space of the titanium dioxide nanometer rod array; the cathode material is a tritiated titanium metal target electrode, and the substrate electrode is FTO conductive glass (surface sheet resistance 8 omega/cm)2)。
The method for preparing a photovoltaic electrochemical cell according to this embodiment comprises the following steps:
(1) preparing a titanium dioxide nanorod array film: FTO conductive glass is used as a substrate electrode, tetrabutyl titanate, hydrochloric acid and water are mixed according to a certain proportion to prepare a hydrothermal reaction solution, a titanium dioxide nanorod array film is grown on the FTO conductive glass by a hydrothermal synthesis method, the diameter of a nanorod is 10 nm-1000 nm, and the diameter length of the nanorod is 500 nm-100 mu m. And then placing the sample in argon gas for high-temperature annealing, and taking the titanium dioxide nanorod array structure grown on the FTO as the anode of the battery.
(2) Preparing a liquid electrolyte: adding 0.5M FeCl3、0.25M FeCl2And 0.2M KCl is dissolved in water to prepare the titanium dioxide nano-rod array film, the prepared liquid electrolyte is uniformly stirred by using a magnetic stirrer at room temperature, then the liquid electrolyte is dripped on the surface of the annealed titanium dioxide nano-rod array, and the sample is heated at low temperature to keep good adhesion between the liquid electrolyte and the titanium dioxide nano-rod array film layer.
(3) Tritiation of titanium metal target: and putting the cleaned titanium metal target into a tritiation furnace, setting the temperature range of the furnace to be 100-800 ℃ and the pressure range to be 100-1000 KPa, and introducing tritium gas or a mixed gas of deuterium and tritium. The metal titanium on the surface absorbs tritium gas or deuterium-tritium mixed gas and reacts with the tritium gas or deuterium-tritium mixed gas to finally generate a tritium-titanium bond or a deuterium-titanium bond to form the tritiated titanium metal target.
(4) Encapsulation of photovoltaic electrochemical cells: the titanium dioxide nanorod array structure synthesized by growth on FTO conductive glass is used as an anode, a titanium tritide metal target electrode is used as a cathode, and the titanium tritide metal target electrode contains Fe3+/Fe2+The liquid electrolyte of the redox couple is filled in the three-dimensional nano-space structure of the anode, the cathode directly covers the anode material coated with the liquid electrolyte, the anode material is placed in a specific mould after being mechanically compressed, and the electronic pouring sealant is injected to fix and seal the device after being solidified, so that the leakage of the electrolyte and the radiation source is prevented.
FIG. 2 is Fe-based alloy of example 13+/Fe2+Working principle diagram of a photovoltaic electrochemical cell with titanium dioxide nanorod array structure of redox couple electrolyte, in a radiation source Ti3H2Under the action of the generated high-energy rays, the titanium dioxide nanorod array structure integrated on the surface of the substrate electrode absorbs the energy of the radiation particles to generate transition, and a large number of electron-hole pairs are generated. Under the action of a built-in electric field formed by the solid-liquid heterojunction,the electron-hole pairs are separated at the anode/electrolyte interface, the electrons are collected by the substrate electrode and then transmitted to the cathode through an external circuit, and are catalyzed by the cathode to react with Fe in the electrolyte solution3+A reduction reaction is carried out, and the holes migrate to the electrolyte under the action of a built-in electric field and then react with Fe in the electrolyte solution2+An oxidation reaction occurs to form a closed loop to generate an output current.
Example 2
As shown in fig. 3, based on example 1, in this embodiment, the surface of the titanium dioxide nanorod array is modified with zirconium dioxide nanoparticles, and the specific sensitization process is as follows: adding an appropriate amount of ZrO (NO)3)2Dissolving in deionized water, adding a certain amount of polyethylene glycol, performing ultrasound treatment on the mixed solution for 30min, dropwise adding a proper amount of ammonia water solution until the pH value of the reaction solution is 9, sealing the back surface of the prepared sample by using a polytetrafluoroethylene adhesive tape to prevent the prepared sample from depositing on the surface of the conductive glass, then putting the sample into the reaction solution for a certain time, taking out the reaction solution, removing the adhesive tape, washing the sample by using deionized water, drying the sample in a constant-temperature drying oven for 12 hours, then putting the dried sample into a clean culture dish for sealed storage, and performing the packaging process of the photovoltaic electrochemical cell as described in example 1. The battery structure includes: 1-FTO substrate electrode, 2-TiO2Nanorod array, 3-ZrO2Nanoparticles, 4-containing Fe3+/Fe2+Inorganic electrolyte, 5-sealed cavity and 6-tritiated titanium cathode.
The method for preparing a photovoltaic electrochemical cell according to this embodiment comprises the following steps:
(1) growing and preparing a titanium dioxide nanorod array film on the FTO substrate electrode;
(2) modifying zirconium dioxide nano-particles on the surface of the titanium dioxide nano-rod array;
(3) will contain Fe3+/Fe2+Electrolyte of the redox couple is injected into the three-dimensional space structure of the titanium dioxide nanorod array;
(4) covering the tritiated titanium metal target on a titanium dioxide nanorod array film as a cathode;
(5) and placing the molded product in a specific mold after mechanical compression, pouring electronic pouring sealant and sealing the device.
FIG. 4 is Fe-based of example 23+/Fe2+Working principle diagram of an irradiation electrochemical cell with a titanium dioxide nanorod array structure of a redox couple electrolyte surface modified with zirconium dioxide3H2Under the action of the generated high-energy rays, the titanium dioxide nanorod array structure integrated on the surface of the substrate electrode absorbs the energy of the radiation particles to generate transition, and a large number of electron-hole pairs are generated. In TiO2/ZrO2Under the action of a built-in electric field formed by the semiconductor heterojunction, electron-hole pairs are separated at an anode/electrolyte interface, electrons are collected by the substrate electrode and then transmitted to the cathode through an external circuit, and the electrons and Fe in an electrolyte solution are subjected to the catalytic action of the cathode3+Reduction reaction to generate Fe2+The holes migrate towards the electrolyte under the action of the built-in electric field due to ZrO2Conduction band potential ratio of TiO2Lower conduction band potential of ZrO2Valence band potential ratio of TiO2Is higher, which will form a band structure of type i contact at the anode/electrolyte interface, ZrO2Electrons on the conduction band can jump to TiO2At the position of the conduction band, taking into account that TNRAs cannot be completely ZrO coated2The coating covers a portion of the photogenerated holes at the working electrode/electrolyte interface with Fe in the electrolyte2+Oxidation reaction to generate Fe3+Such a band structure facilitates separation of the radiative electron-hole pairs and inhibits recombination of the electron-hole pairs, thereby improving the output power of the photovoltaic electrochemical cell.
FIGS. 5(a) and (b) show the FESEM images of the top view and its partial enlarged view, respectively, of a titanium dioxide nanorod array (TNRAs) grown on FTO, indicating that the entire FTO substrate is coated with high density TiO2The nanorods uniformly covered the cubic pillar shape. It can be clearly observed that the TNRAs film grown by the hydrothermal method is formed by the arrangement of compact flat, highly ordered quadrangular-prism-shaped nanorods, the top surface of which is composed of many coarse small grids and the side surfaces of which are smooth. All TNRAs were almost perpendicular to the FTO substrate, with nanorods approximately 100nm on a side and approximately 100nm in heightIs 3 um.
FIG. 5(c) shows TiO2Cross-sectional side view of nanorod array. Hydrothermal growth over a period of time, [001 ]]Directionally grown TNRAs nearly perpendicular to the FTO substrate, TiO2The nanorods had diameters of about 3 μm and about 100nm, respectively. FIG. 5(d) shows the EDS energy spectrum of TNRAs grown on an FTO substrate, and it can be found that the sample is composed mainly of Ti, O, Si and Sn elements, wherein the Ti and O elements are derived from TiO2While Si and Sn are elemental peaks of the FTO substrate, as also confirmed in the subsequent XRD spectrum. The combination of SEM results shows that the invention successfully prepares TiO2A nanorod array structure.
FIG. 6 shows Ar-TNRAs and ZrO2XRD spectrogram of @ Ar-TNRAs sample, all diffraction peaks and TiO2The rutile phase (SG, P42/mnm; JCPDS No.88-1175, a) b)0.4517nm and c)0.2940nm) are very well matched. The diffraction peaks of TNRAs grown on the FTO substrate at 36.1 degrees, 41.3 degrees, 62.8 degrees and 69.9 degrees respectively correspond to TiO2The (101), (111), (002) and (112) crystal faces in rutile phase PDF standard card No. 65-0192. Wherein the diffraction peak intensities of the (101) crystal face and the (002) crystal face of TNRAs grown on the FTO substrate are relatively strong, and the other diffraction peaks are relatively weak. TiO 22Nanorod edge [001 ]]The direction is grown, and the growth axis is parallel to the normal direction of the surface of the substrate. In addition, diffraction peaks do not exist in a polycrystalline or powder sample generally, which strongly indicates that the nanorods are not only aligned in the whole length, but also are monocrystalline, and the orderly arranged one-dimensional nanorod array can provide a direct channel for the transportation of carriers, so that the separation and migration rate of radiation carriers can be effectively improved, and the recombination of electron-hole pairs can be inhibited. Due to ZrO2The composite content is small, the grain diameter is small, and the ZrO is sensitized2The crystal form and the crystallization degree of the sample are not obviously changed.
FIG. 7(a) is Ar-TNRAs and ZrO2XPS contrast full spectrum of the sample of @ Ar-TNRAs shows that ZrO is2The existence of Zr element in the sample of @ Ar-TNRAs, and the existence of Ti and O elements derived from TiO2A nanorod array. As shown in FIG. 7(b), one major peak (O1) in the XPS spectrum of O1 s may beTo correspond to TiO2And ZrO2The O lattice (located at 529.8eV and 530.3eV, respectively) of (a) and the other major peak (O2) located at 531.7eV may be attributed to oxygen molecules absorbed on the sample surface. Furthermore, ZrO2The atomic percentage of O1 in the sample of @ Ar-TNRAs was higher than that in the sample of Ar-TNRAs, which is likely to be comparable to ZrO2Is relevant to the introduction of (1). As shown in FIG. 7(c), Ar-TNRAs and ZrO2The Ti 2p XPS spectrum of the sample of @ Ar-TNRAs has a relatively high coincidence ratio, and the peaks at 464.8eV, 464.1eV and 458.7eV correspond to Ti 4+2p1/2、Ti 3+2p1/2And Ti 4+2p3/2Energy levels, which also demonstrate that the reducing annealing atmosphere introduces OVs and Ti3+A defective state. As shown in FIG. 7(d), Zr 3d peaks at 182.0 and 184.3eV correspond to Zr 3d5/2and Zr 3d3/2Two energy levels, which closely match the tetravalent oxidation state of zirconium. These results show that the surface of the prepared titanium dioxide nanorod array sample is indeed covered with zirconium dioxide.
FIG. 8(a) shows Ar-TNRAs and ZrO2And an ultraviolet-visible light (UV-VIS) absorption spectrum chart of the @ Ar-TNRAs sample in a range of 250-700 nm. All samples were found to have high activity under uv irradiation, low absorption of light at wavelengths greater than 400nm, and a certain degree of visible light blindness, which also reflects the wide band gap of the prepared samples. Furthermore, the surface is modified with ZrO2The Ar-TNRAs sample of (2) had a slight enhancement in the absorption of UV light. The forbidden band width value of TNRAs samples can be calculated by an ultraviolet absorption spectrum through a Kubelka Munk function, the specific band gap value is shown in a figure 8(b), the forbidden band width of Ar-TNRAs is about 3.01eV, and OVs and Ti are introduced into reducing annealing atmosphere3+And a shallow energy level band (electron trap) is formed below the conduction band due to the defect state, so that the density of the carriers is increased, the recombination of electron-hole pairs is effectively inhibited, and the separation of the carriers is promoted. In addition, the TNRAs surface is modified with ZrO2After that, the band gap is slightly decreased. This is because the increase in surface charge leads to an increase in absorption of ultraviolet light, and ZrO2ZrO of @ Ar-TNRAs2The coating may change the excitation pattern upon irradiation,and inhibits recombination of electron-hole pairs.
To study a material based on Ar-TNRAs and ZrO2The electric output performance of the photovoltaic electrochemical cell of the @ Ar-TNRAs sample is tested. For Ti3H2The irradiation characteristics of the/TNRAs/FTO transducer device were tested. In the experiment, a radioactive isotope source is adopted as a titanium metal target (Ti) for absorbing tritium3H2) The total activity is 5Ci, the diameter is 3cm, the thickness is 2mm, and the area is about 7cm2. The actual effective contact area is 3.8cm after the tritium source is assembled on the device2,Ti3H2The average energy of the radiation source was 5.7keV and the half-life was 12.5 years. The experimental test site is in the isotope research institute of the national institute of atomic energy science (Beijing) in China. Removing a certain amount of FeCl with a pipette3Electrolyte injected between the working electrode and the cathode to assemble a sandwich structure (Ti)3H2/TNRAs/FTO). Compared with the planar solid radiation source directly contacting with the energy conversion device, the filling of the liquid electrolyte can enable the contact between the planar solid radiation source and the energy conversion device to be tighter, so that the energy conversion efficiency of the photovoltaic electrochemical cell is greatly improved. FIG. 9(a) shows FeCl filling between the working electrode and the cathode under dark conditions3Electrolyte solution based on the I-V curve of an Ar-TNRAs device. The device has little photovoltaics effect when irradiated without ultraviolet light and radiation source. FIG. 9(b) shows a radial electrochemical cell at Ti, also based on Ar-TNRAs3H2When the radiation source irradiates, the I-V curve chart shows that obvious radiation volt effect and open circuit voltage (V) of the battery are observedoc) 0.21V, short-circuit current (I)sc) Is 235 uA. FIG. 9(c) shows a ZrO based2@ Ar-TNRAs beta-volt battery at Ti3H2The I-V curve chart of the radiation source irradiation case also shows the remarkable radiation volt effect, and the open circuit voltage (V) of the batteryoc) 0.23V, short-circuit current (I)sc) Is 241.9 uA. FIG. 9(d) shows a beta-volt cell based on Ar-TNRAs at Ti3H2The radiation current is basically kept stable in an I-t curve chart under the irradiation condition of the radiation source.
Table 1 details the results based on Ar-TNRAs and ZrO2The performance parameters of the photovoltaic electrochemical cell of @ Ar-TNRAs, wherein the calculation formula of the energy conversion efficiency is as follows:
wherein, PmaxRepresents the maximum output power density, P, of a beta-volt batterysourceIs a radiation source63The radiation power of Ni, phi represents the activity of the radiation source and is given by Curie (Ci), EavgIs a radiation source63The average electron energy of Ni is in eV, e is the charge of the electron and in coulomb (C). FF stands for the fill factor of a beta-volt battery, which can be expressed as FF ═ Pmax/Isc·Voc。
TABLE 1
In the invention, the radioactivity of the radiation electrode and the radiation semiconductor is from one or more stable elements in the electrode or the three-dimensional nanostructure of the semiconductor to be replaced by the radioactive isotopes of the same type, and the electrolyte is added between the anode and the cathode, so that the existence of the electrolyte can effectively absorb the ionizing radiation kinetic energy of radiation particles, thereby effectively eliminating the radiation damage to the three-dimensional nanostructure of the semiconductor, and a contact interface is formed among the cathode, the electrolyte and the anode, so that the contact interface has a high potential barrier, a large number of electron-hole pairs generated under the radiation effect can be effectively separated, the carrier recombination rate is reduced, and the energy conversion efficiency of the radiation electrochemical cell is effectively improved.