CN111534834B

CN111534834B - Corrosion-resistant photo-anode composite material and preparation method thereof

Info

Publication number: CN111534834B
Application number: CN202010205940.XA
Authority: CN
Inventors: 俞书宏; 刘国强; 阳缘; 李毅
Original assignee: University of Science and Technology of China USTC
Current assignee: University of Science and Technology of China USTC
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2021-12-14
Anticipated expiration: 2040-03-19
Also published as: CN111534834A

Abstract

The invention provides an anticorrosive photo-anode composite material, which is prepared from RGO nanosheets and CdSe_1‑xTe_xThe nanowire and the cocatalyst; the CdSe_1‑xTe_xThe nanowires and the cocatalyst are dispersed on the surface of the RGO nanosheets; the present application also provides a corrosion resistant photoanode composite. The photoanode composite material provided by the invention enhances CdSe by introducing reduced graphene oxide as a carrier transport layer_1‑xTe_xHole transport between the nanowire and the cocatalyst, thereby reducing the photo-generated hole pair CdSe_1‑xTe_xPhoto-etching effect of nano-wire, photo-anode nano-wire with high stability for design and developmentThe material provides a new approach.

Description

Corrosion-resistant photo-anode composite material and preparation method thereof

Technical Field

The invention relates to the technical field of nano materials, in particular to a corrosion-resistant photo-anode composite material and a preparation method thereof.

Background

Photoelectrochemical (PEC) hydrogen production provides a promising and sustainable way to address the energy crisis. However, the instability and low energy conversion efficiency of the catalyst affect its role in practical applications. The instability of the photoelectrode is mainly caused by photo-erosion of the semiconductor, and photo-induced generation of electrons (holes) can drive degradation or decomposition of the semiconductor itself in the electrolyte solution. However, the rapid consumption of photo-generated electrons (holes) can effectively suppress the occurrence of photo-etching reaction, while also enhancing the separation efficiency of photo-generated charges.

Among many semiconductor materials, the II-VI semiconductor CdX (X ═ Te and Se) having a band gap of 1.4 to 1.7eV has a strong absorption ability for visible light and near infrared light. Suitable band gap and high absorption section coefficient (alpha, 10)⁵cm^-1) Making such materials potentially useful as efficient photoelectrodes. However, cadmium chalcogenides (such as CdTe and CdSe) have a very severe photo-etching process, and the photoelectrode is oxidized by photogenerated holes to cause deactivation. For example, the photoetching process of CdSe under illumination is shown in (1): CdSe +2h⁺———Cd²⁺+Se (1)。

In order to suppress the photo-etching process in such a photoelectrode, it is necessary to rapidly consume photo-generated holes or to suppress the occurrence of oxidation reactions in the photoelectrode. At present, the common methods of scientists are to increase the rate of transfer and consumption of photogenerated holes, such as building hetero/homo junctions, introducing promoters and adding hole sacrificants. Furthermore, isolating the semiconductor material from the electrolyte solution by creating a passivation layer is also an effective method to prevent photo-corrosion. Although these methods can significantly improve the stability of photoelectrodes, there are some key issues to be addressed, such as the rate limiting of hole transport in hetero/homo junction or semiconductor/co-catalyst systems and the shielding of the active sites by passivation layers. The presence of these problems inhibits the improvement of the energy conversion efficiency.

Reduced graphene oxide nanoplatelets (RGO) have unique electronic properties, large specific surface area and excellent optical properties and are an irreplaceable component of PEC photoelectrodes. In addition, RGO can be used as an effective electron donor and a good hole extraction layer, which can improve the stability of a semiconductor by increasing the transport ability of photogenerated carriers. However, the efficiency of depletion of photo-generated holes is still particularly low due to the shielding effect caused by RGO. Thus, it is still necessary to provide a photoanode material that is resistant to photo-corrosion.

Disclosure of Invention

The invention aims to provide a photo-anode composite material with photo-corrosion resistance.

In view of the above, the present application provides a corrosion-resistant photo-anode composite material, which is prepared from RGO nanosheets and CdSe_1-xTe_xThe nanowire and the cocatalyst; the CdSe_1-xTe_xThe nanowires and the cocatalyst are dispersed on the surface of the RGO nanosheets;

wherein x is more than 0 and less than 1.

Preferably, the cocatalyst is selected from PdS, RuO₂And a CoPi.

Preferably, the photoanode composite material is used as a base, the content of the RGO nanosheet is 0.1-5 wt%, and the content of the cocatalyst is 0.1-1 wt%.

The application also provides a preparation method of the corrosion-resistant photo-anode composite material, which comprises the following steps:

A) mixing CdSe_1-xTe_xThe nano-wire is dispersed in a GO-containing solution, and CdSe is obtained by an ultrasonic and hydrothermal method_1-xTe_xa/RGO composite nanomaterial; x is more than 0 and less than 1;

B) the CdSe is added_1-xTe_xthe/RGO composite nano material is dispersed in a solution containing cocatalyst nano particles, and the corrosion-resistant photo-anode composite material is obtained by an ultrasonic and hydrothermal method.

Preferably, the cocatalyst is PdS nanoparticles; the preparation method of the PdS nano-particles comprises the following steps:

mixing a palladium source and a sulfur source in an aqueous solution, and obtaining PdS nano-particles by a hydrothermal method;

the palladium source is selected from one or more of palladium chloride, palladium nitrate, palladium acetate and palladium tetrachloride; the sulfur source is selected from one or more of sulfur powder, thiourea and sodium sulfide.

Preferably, the CdSe_1-xTe_xThe nanowires were prepared as follows:

mixing Te_xSe_y@Se_1-x-yMixing and heating the nanowire and the cadmium source in the aqueous solution, and reacting to obtain CdSe_1-xTe_xA nanowire; x is more than 0 and less than 1, and y is more than 0 and less than 1;

the cadmium source is selected from one or more of cadmium chloride, cadmium nitrate tetrahydrate and cadmium acetate.

Preferably, in the step A), the temperature of the hydrothermal reaction is 140-180 ℃, the heating rate is 5-10 ℃/min, and the time is 6-18 h.

Preferably, in step A), the CdSe_1-xTe_xThe content of the RGO in the/RGO composite nano material is 0.1-2 wt%.

Preferably, in the step B), the temperature of the hydrothermal reaction is 140-180 ℃, the heating rate is 5-10 ℃/min, and the time is 6-18 h; the hydrothermal reaction is carried out in a reaction kettle.

The application provides a corrosion-resistant photo-anode composite material which is prepared from RGO nanosheets and CdSe_1-xTe_xThe nanowire and the cocatalyst; the CdSe_1-xTe_xNanowires and the co-catalyst are dispersed on the surface of the RGO nanoplates. The light anode composite material provided by the application combines the hole transmission capability of RGO and the hole extraction layer formed by the cocatalyst on the hole consumption capability, so that the composite material can realize the rapid consumption and separation of the holes, finally has the light corrosion resistance characteristic, and improves the energy conversion efficiency of the photoelectrode.

Drawings

FIG. 1 shows TexSe prepared in example 1 of the present invention_y@Se_1-x-yA nanowire Transmission Electron Microscope (TEM) image;

FIG. 2 shows CdSe prepared according to example 1 of the present invention_1-xTe_x(CST) nanowire TEM images;

FIG. 3 is a TEM image and a powder X-ray spectrum (XRD) of PdS nanoparticles prepared in example 2 of the present invention;

FIG. 4 shows CdSe prepared in examples 3-4 of the present invention_1-xTe_x/RGO (CST/RGO) and CdSe_1-xTe_xTEM images of/RGO/PdS (CST/RGO/PdS) composite nanomaterials;

FIG. 5 shows CdSe prepared in examples 3-4 of the present invention_1-xTe_x/RGO (CST/RGO) and CdSe_1-xTe_xScanning Electron Microscope (SEM) images of/RGO/PdS (CST/RGO/PdS) composite nanomaterials;

FIG. 6 shows CdSe prepared in examples 1-4 of the present invention_1-xTe_x(CST) nanowire, CdSe_1-xTe_x/RGO (CST/RGO) and CdSe_1-xTe_xPowder X-ray spectra of/RGO/PdS (CST/RGO/PdS) composite nanomaterials;

FIG. 7 shows CdSe prepared in example 4 of the present invention_1-xTe_xHigh resolution transmission electron microscope images of/RGO/PdS (CST/RGO/PdS) composite nanomaterials;

FIG. 8 shows CdSe prepared according to example 1 of the present invention_1-xTe_x(CST) EDS elemental plane distribution image of nanowires;

FIG. 9 shows CdSe prepared in example 3 of the present invention_1-xTe_xEDS element plane distribution image of/RGO (CST/RGO) composite nano material;

FIG. 10 shows CdSe prepared in example 4 of the present invention_1-xTe_xEDS element plane distribution image of/RGO/PdS (CST/RGO/PdS) composite nano material;

FIG. 11 shows CdSe prepared in examples 1-4 of the present invention_1-xTe_x(CST) nanowire, CdSe_1-xTe_x/RGO (CST/RGO) and CdSe_1-xTe_xUV-vis absorption spectra of/RGO/PdS (CST/RGO/PdS) composite nanomaterials;

FIG. 12 shows CdSe prepared in examples 1-4 of the present invention_1-xTe_x(CST) nanowire, CdSe_1-xTe_x/RGO (CST/RGO) and CdSe_1-xTe_xCurrent-voltage, current-time, and amperage-time maps of/RGO/PdS (CST/RGO/PdS).

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

Based on the problem of photo-corrosion resistance of the photo-anode material, the application provides a photo-anode composite material which realizes the rapid decomposition and consumption of photo-generated holes in a photo-electrode and improves the energy conversion efficiency. Specifically, the embodiment of the invention discloses an anti-corrosion photo-anode composite material which is prepared from RGO nanosheets and CdSe_1-xTe_xThe nanowire and the cocatalyst; the CdSe_1-xTe_xThe nanowires and the cocatalyst are dispersed on the surface of the RGO nanosheets;

wherein x is more than 0 and less than 1.

In the photoanode composite material provided by the application, the CdSe_1-xTe_xThe nano-wire and the cocatalyst are uniformly dispersed on the surface of the RGO nano-sheet, and the CdSe_1-xTe_xThe nanowires and the promoter do not differ significantly in position. In the present application, the promoter is in particular an oxidation promoter, chosen from PdS, RuO₂And CoPi, in particular embodiments, the promoter is a PdS nanoparticle.

In the photoanode composite material, the photoanode composite material is taken as a base, the content of the RGO nanosheet is 0.1-5 wt%, and the content of the cocatalyst is 0.1-1 wt%.

B) mixing CdSe_1-xTe_xthe/RGO composite nano material is dispersed in the mixed solution containing the assistantIn the solution of the catalyst nano particles, the corrosion-resistant photo-anode composite material is obtained by an ultrasonic and hydrothermal method.

The sources of all raw materials are not particularly limited in the invention, and the raw materials can be either commercially available or self-made.

Wherein, the CdSe_1-xTe_xThe nanowire has x greater than zero and less than 1, specifically, x can be selected from 0.33, 0.20, 0.14, 0.11, 0.08, and 0.06, and in some embodiments provided by the present invention, x is preferably 0.14.

In the present invention, the CdSe_1-xTe_xThe nano-wire is prepared by a hydrothermal synthesis method; i.e. with Te_xSe_y@Se_1-x-yThe nano wire is a hard template, and the cadmium source and Te are reacted at a certain reaction temperature_xSe_y@Se_1-x-yNanowire reaction to obtain CdSe_1-xTe_xA nanowire; the preparation method specifically comprises the following steps:

mixing Te_xSe_y@Se_1-x-yMixing and heating the nanowire and a cadmium source in an aqueous solution to react to obtain CdSe_1-xTe_xA nanowire; the cadmium source is preferably a cadmium salt, and more preferably one or more of cadmium chloride, cadmium nitrate tetrahydrate and cadmium acetate; the temperature of the mixing and heating reaction is preferably 140-180 ℃, more preferably 160-180 ℃, and further preferably 160 ℃; the heating rate is preferably 5-10 ℃/min, more preferably 8-10 ℃/min, and most preferably 9 ℃/min; the mixing and heating reaction time is preferably 6-18 h, and more preferably 10-12 h. In the above Te_xSe_y@Se_1-x-yIn the nanowires, x is greater than zero and less than 1, and the value of y represents the amount of Se element forming an alloy phase with Te element in the nanowires of the core-shell structure, and although the value cannot be specifically determined, the value thereof is greater than zero and less than 1; in specific values, x can be selected from 0.33, 0.20, 0.14, 0.11, 0.08 and 0.06; in a particular embodiment, said x is preferably 0.14.

The CdSe_1-xTe_xThe preparation of the nano-wire is more specifically as follows: reacting TexSe_y@Se_1-x-yMixing and heating the nanowire and the cadmium source in the aqueous solution to the reaction temperature of 140-180 DEG CPreferably, the temperature is kept at 160-180 ℃, and more preferably, the temperature is kept at 160 ℃; the heating reaction time is preferably 6-18 h, and more preferably 10-12 h; after the reaction is finished, cooling. The cooling method is a cooling method known to those skilled in the art, and is not particularly limited, and in the specific embodiment, the cooling method is natural cooling; after cooling, the CdSe is obtained by centrifugation and washing_1-xTe_xA nanowire; the washing is preferably carried out with hexane and ethanol.

The application then combines the CdSe with a binder_1-xTe_xThe nanowire is compounded with RGO to obtain CdSe_1-xTe_xa/RGO composite nanomaterial; the CdSe_1-xTe_xThe synthesis method of the/RGO composite nano material is preferably an ultrasonic method and a hydrothermal method, and specifically comprises the following steps:

mixing CdSe_1-xTe_xMixing the nanowire with GO, and then obtaining CdSe through ultrasound and hydrothermal treatment_1-xTe_xthe/RGO composite nano material.

During the above preparation, the GO is preferably added in the form of an aqueous GO solution; the concentration of GO in the GO water solution is preferably 0.1-0.5 mg/ml, more preferably 0.2-0.4 mg/ml, and still more preferably 0.35 mg/ml; in the present invention, CdSe is preferably first introduced_1-xTe_xThe nano-wires are dispersed in the water solution and then mixed with the chloroauric acid solution; the CdSe_1-xTe_xAnd promoting CdSe under ultrasound after GO is mixed_1-xTe_xCompounding with GO; the ultrasonic treatment time is preferably 10-60 min, more preferably 20-50 min, and most preferably 30 min; the temperature of the mixing and heating reaction is preferably 140-180 ℃, more preferably 160-180 ℃, and further preferably 180 ℃; the heating rate is preferably 5-10 ℃/min, more preferably 8-10 ℃/min, and most preferably 9 ℃/min; the mixing and heating reaction time is preferably 6-18 h, and more preferably 10-12 h; after the reaction is finished, the product is precipitated, centrifuged and washed by ethanol to obtain CdSe_1-xTe_xa/RGO composite nanomaterial; the washing is preferably with ethanol. The CdSe_1-xTe_xThe mass fraction of RGO in the/RGO composite nano material is preferably 0.1-5%, more preferably 0.1-3%, and still more preferably 0.1 ∞2%, most preferably 0.1 to 1.5%.

In the invention, the cocatalyst is specifically an oxidation cocatalyst and can be selected from PdS nanoparticles and RuO₂One or more of nanoparticles and CoPi nanoparticles, in particular embodiments, the promoter is selected from PdS nanoparticles, preferably prepared according to the following method: mixing a palladium source and a sulfur source in an aqueous solution, and obtaining PdS nano-particles by a hydrothermal method; the palladium source is preferably one or more of palladium chloride, palladium nitrate, palladium acetate and palladium tetrachloride; the sulfur source is preferably one or more of sulfur powder, thiourea and sodium sulfide; the temperature of the mixing and heating reaction is preferably 150-180 ℃, more preferably 160-180 ℃, and further preferably 160 ℃; the heating rate is preferably 5-10 ℃/min, more preferably 8-10 ℃/min, and most preferably 9 ℃/min; the mixing and heating reaction time is preferably 6-18 h, and more preferably 10-12 h. In a specific embodiment, the reaction is more specifically: mixing and heating palladium tetrachloride and sulfur powder in an aqueous solution until the reaction temperature is kept at 140-180 ℃, preferably 160-180 ℃, and then preferably 160 ℃; the heating reaction time is preferably 6-18 h, and more preferably 10-12 h. After the reaction is finished, cooling; the cooling method is not particularly limited, and natural cooling is preferable in the present invention; after cooling, preferably centrifuging and washing to obtain PdS nano particles; the washing is preferably carried out with ultrapure water or ethanol.

The last application will be said of CdSe_1-xTe_xRespectively dispersing the/RGO composite nano material and the PdS nano particles in an aqueous solution, mixing the two dispersed solutions after dispersion, stirring and heating for reaction; the temperature of the mixing and heating reaction is preferably 140-180 ℃, more preferably 160-180 ℃, and further preferably 180 ℃; the heating rate is preferably 5-10 ℃/min, more preferably 8-10 ℃/min, and most preferably 9 ℃/min; the mixing and heating reaction time is preferably 6-18 h, and more preferably 10-12 h. After the heating reaction is finished, the product is preferably precipitated, centrifuged and washed by ethanol to obtain CdSe_1-xTe_x/RGO/PdS composite nano materialFeeding; the washing is preferably carried out with ultrapure water or ethanol.

In the above process, CdSe is used_1-xTe_xBased on the/RGO composite nano material, PdS nano particles are further compounded on the RGO nano sheet to obtain CdSe_1-xTe_xthe/RGO/PdS composite nano material. The CdSe_1-xTe_xThe mass fraction of RGO in the/RGO/PdS composite nano material is 0.1-5%, more preferably 0.1-3%, still more preferably 0.1-2%, and most preferably 0.1-1.5%; the mass fraction of PdS is 0.1-1%, more preferably 0.1-0.8%, and most preferably 0.1-0.5%;

the photoanode composite material provided by the invention enhances CdSe by introducing reduced graphene oxide as a carrier transport layer_1-xTe_xHole transport between the nanowire and the cocatalyst, thereby reducing the photo-generated hole pair CdSe_1-xTe_xThe photo-etching effect of the nano-wire provides a new approach for designing and developing photo-anode nano-materials with high stability.

For further understanding of the present invention, the following examples are given to illustrate the corrosion-resistant photoanode composite material provided by the present invention, and the scope of the present invention is not limited by the following examples.

The reagents used in the following examples are all commercially available.

Example 1

CdSe_1-xTe_xPreparing the nano wire: adding 0.9mmol of cadmium nitrate Cd (NO)₃)₂·4H₂O and 0.9mmol of Te_xSe_y@Se_1-x-y(0 < x < 1; 0 < y < 1; in a specific embodiment, the x is preferably 0.14.) the nanowires are mixed and stirred vigorously, the mixture is transferred to a 100mL polytetrafluoroethylene liner and packaged in a stainless steel autoclave; then the stainless steel autoclave is sealed and heated at 160 ℃ for 12 hours; the heating rate of the heating reaction is 8-10 ℃/min; after the reaction is finished, cooling the reaction product to room temperature; the final product, CdSe, was collected by centrifugation (10000rpm, 3min)_1-xTe_xNanowires were washed 3 times with ethanol for further use.

The TexSe used in example 1 was subjected to transmission electron microscopy_y@Se_1-x-yAnalyzing the nanowires to obtain a transmission electron microscope image as shown in FIG. 1; as can be seen from FIG. 1, Te_xSe_y@Se_1-x-yThe diameter of the nanowire is about 20nm, and the surface of the nanowire is smooth;

the CdSe obtained in example 1 were subjected to transmission electron microscopy_1-xTe_xThe nanowires were analyzed and their transmission electron microscopy images were obtained as shown in FIG. 2; as can be seen from FIG. 2, CdSe_1-xTe_xThe nano-wire is composed of nano-particles with small size, the diameter is about 50nm, and the surface is rough.

Example 2

Preparing PdS nano particles: 3mL of palladium tetrachloride HPdCl₄(25mM) and 1g thiourea, transferring the mixture to a 100mL polytetrafluoroethylene lining, and packaging in a stainless steel autoclave; then the stainless steel autoclave is sealed and heated at 160 ℃ for 12 hours; the heating rate of the heating reaction is 8-10 ℃/min; after the reaction is finished, cooling the reaction product to room temperature; the PdS nanoparticles of the final product were collected by centrifugation (10000rpm, 3min) and washed 3 times with ethanol for further use.

The PdS nanoparticles used in example 2 were analyzed by transmission electron microscopy and X-ray diffraction, and the transmission electron microscopy pattern and X-ray pattern obtained are shown in fig. 3; as can be seen from FIG. 3, the PdS nanoparticles have uniform size, and all diffraction peaks in the X-ray diffraction pattern of the PdS nanoparticles can be assigned to PdS of tetragonal phase (JCPDS card number 25-1234, space group P42/m), and the pattern shows that the crystallinity of the PdS nanoparticles before non-annealing is poor.

Example 3

CdSe_1-xTe_xPreparation of/RGO composite nano material: adding 0.9mmol of CdSe_1-xTe_xMixing the nanowires with 0.5mL of GO aqueous solution (0.35mg/mL) and stirring vigorously, then carrying out ultrasonic treatment on the solution for 30 minutes, transferring the mixed solution to a 100mL polytetrafluoroethylene lining and packaging the polytetrafluoroethylene lining in a stainless steel autoclave; then sealing the stainless steel autoclave and heating at 180 ℃ for 12 hours; heating ofThe temperature rise rate of the reaction is 8-10 ℃/min; after the reaction is finished, cooling the reaction product to room temperature; the final product, CdSe, was collected by centrifugation (10000rpm, 3min)_1-xTe_xthe/RGO composite nanomaterial was washed 3 times with ethanol for further use.

Example 4

CdSe_1-xTe_xPreparation of/RGO/PdS composite nano material: CdSe prepared in example 3_1-xTe_xMixing the/RGO composite nano material with 0.3mL of PdS nano particles prepared in the example 2, stirring the mixture vigorously, then carrying out ultrasonic treatment on the solution for 30 minutes, transferring the mixed solution to a 100mL polytetrafluoroethylene lining, and packaging the mixed solution in a stainless steel autoclave; then sealing the stainless steel autoclave and heating at 180 ℃ for 12 hours; the heating rate of the heating reaction is 8-10 ℃/min; after the reaction is finished, cooling the reaction product to room temperature; the final product, CdSe, was collected by centrifugation (10000rpm, 3min)_1-xTe_xthe/RGO/PdS composite nanomaterial was washed 3 times with ethanol for further use.

The CdSe obtained in examples 3-4 were examined by transmission electron microscope_1-xTe_xRGO and CdSe_1-xTe_xThe transmission electron microscopy image of the/RGO/PdS composite nano-material is shown in FIG. 4. Scanning Electron microscope was used to measure the CdSe obtained in examples 3-4_1-xTe_xRGO and CdSe_1-xTe_xthe/RGO/PdS composite nano-material is analyzed, and a scanning electron microscope image of the/RGO/PdS composite nano-material is shown in FIG. 5; as can be seen from FIGS. 4 and 5, CdSe_1-xTe_xThe nanowires and the PdS nanoparticles are uniformly dispersed on the RGO nanosheets.

X-ray diffraction of CdSe obtained in examples 3-4_1-xTe_xRGO and CdSe_1-xTe_xthe/RGO/PdS composite nano material is analyzed, and the X-ray spectrum is shown in figure 6; as can be seen from FIG. 6, CdSe_1-xTe_xAll diffraction peaks in the X-ray diffraction pattern of the nanowires can be assigned to the mixed phase of wurtzite CdSe (JCPDS card numbers 08-0459, spatial group P63mc) and wurtzite CdSe (JCPDS card numbers 19-0191, spatial group F-43m) due to the fact thatTellurium element is doped, and the XRD peak shifts to a low 2 theta value as a whole; peaks between 30 ° and 32 ° in 2 θ were assigned to PdS in the tetragonal phase (JCPDS card numbers 25-1234, space group P42/m), consistent with the XRD pattern of PdS nanoparticles.

CdSe prepared in example 4 by high resolution transmission electron microscope_1-xTe_xthe/RGO/PdS composite nano-material is analyzed to obtain a high-resolution transmission electron microscope image of the/RGO/PdS composite nano-material as shown in FIG. 7; CdSe in images_1-xTe_xThe nanowires show a lattice spacing of 0.36nm, which is attributed to the (100) crystal plane of wurtzite CdSe; HRTEM images of PdS nanoparticles show a lattice spacing of 0.22nm, which is attributed to the (212) lattice plane.

CdSe obtained in example 1 were analyzed by an energy spectrometer_1-xTe_xAnalyzing the nanowires to obtain an EDS element surface distribution diagram of the nanowires, as shown in FIG. 8; as can be seen from FIG. 8, Cd and Se are uniformly distributed in the nanowire, while Te is mainly distributed in CdSe_1-xTe_xTe used in the formation and synthesis of such core-shell structures in the core of nanowires_xSe_y@Se_1-x-yThe nanowire template is relevant.

CdSe obtained in example 3 was analyzed by an energy spectrometer_1-xTe_xAnalyzing the/RGO composite nano material to obtain an EDS element surface distribution diagram of the/RGO composite nano material, wherein the EDS element surface distribution diagram is shown in figure 9; as can be seen from FIG. 9, CdSe_1-xTe_xThe nanowires remain core-shell structured and uniformly dispersed on the RGO nanoplatelets.

CdSe obtained in example 4 was analyzed by an energy spectrometer_1-xTe_xAnalyzing the/RGO/PdS composite nano material to obtain an EDS element surface distribution diagram of the/RGO/PdS composite nano material, wherein the EDS element surface distribution diagram is shown in a figure 10; as can be seen from FIG. 10, Pd and S elements are uniformly distributed in the PdS nanoparticles, and CdSe_1-xTe_xThe nanowires and the PdS nanoparticles are uniformly dispersed on the RGO nanosheets.

For CdSe obtained in examples 1-4_1-xTe_xNanowire, CdSe_1-xTe_xRGO and CdSe_1-xTe_xThe ultraviolet-visible absorption spectrum of the/RGO/PdS composite nano material is analyzed to obtain the UV-vis absorption spectrum chart, as shown in FIG. 11Shown in the figure.

For CdSe obtained in examples 1-4_1-xTe_xNanowire, CdSe_1-xTe_xRGO and CdSe_1-xTe_xThe photoelectrochemistry hydrogen production performance of the/RGO/PdS composite nano material is analyzed to obtain a current-voltage map, a current-time map and a current intensity-time map, as shown in figure 12.

The application simulates sunlight (lambda is more than 420nm, 100mW cm)^-2) Irradiation and Na₂SO₃/Na₂S as hole sacrificial agent, their PEC performance was tested using photoanodes of controlled thickness. By adjusting CdSe_1-xTe_xNanowire to RGO nanosheet ratio and CdSe_1-xTe_xThe ratio of nanowires to PdS nanoparticles, the present application optimizes the performance of these photoanodes. As shown in FIG. 12i, CdSe_1-xTe_xPhotocurrent density of/RGO/PdS is from-0.2V_RHEBegins to increase and is at 1.0V_RHEThe lower value reaches 2.5mA cm^-2(ii) a However, at 1.0V_RHEUnder bias, CdSe_1-xTe_xNanowires and CdSe_1-xTe_xThe photocurrent densities of/RGO were only 0.6 and 1.5 mA-cm^-2. Thus, CdSe_1-xTe_xThe improvement of PEC performance of the/RGO/PdS composite nanomaterial is due to the fast transport and depletion process of holes provided by the hole extraction layer based on RGO nanoplates and PdS nanoparticles.

Applicant has also observed CdSe_1-xTe_xNanowire, CdSe_1-xTe_xRGO and CdSe_1-xTe_xThe photo-anode of the/RGO/PdS composite nano material is tested and compared with the photo-anode, and all samples are tested under the conditions of one sunlight irradiation and 0.5V_RHEUnder a bias voltage of (1) for a given time. As shown in fig. 12ii-iii (in the iii diagram, the left data in each of the four sets of histograms is CdSe_1-xTe_xData of nanowire, intermediate data being CdSe_1-xTe_xData for/RGO, CdSe on the right_1-xTe_xData of/RGO/PdS), CdSe_1-xTe_xthe/RGO/PdS photo-anode is arranged onThe PEC test showed a stable photocurrent, losing only 7% of its initial photocurrent after 2 h; in sharp contrast, CdSe was sampled every 30min_1-xTe_xNanowire, CdSe_1-xTe_xRGO and CdSe_1-xTe_xThe PEC performance of the/RGO/PdS photoanode decayed continuously and lost 50%, 30% and 18% of its initial photocurrent after 2h, respectively. Clearly, the hole extraction layer based on RGO nanoplates and PdS nanoparticles significantly delayed the onset of photo-erosion by rapidly transferring and rapidly consuming photo-generated holes compared to other samples.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An anticorrosion composite photoanode material is prepared from RGO nanosheets and CdSe_1-xTe_xThe nanowire and the cocatalyst; the CdSe_1-xTe_xThe nanowires and the cocatalyst are dispersed on the surface of the RGO nanosheets;

wherein x is more than 0 and less than 1;

the cocatalyst is selected from PdS;

based on the photoanode composite material, the content of the RGO nanosheet is 0.1-5 wt%, and the content of the cocatalyst is 0.1-1 wt%.

2. A method of making a corrosion resistant photoanode composite as claimed in claim 1, comprising the steps of:

B) the CdSe is added_1-xTe_xthe/RGO composite nano material is dispersed in a solution containing PdS nano particles, and the corrosion-resistant photo-anode composite material is obtained by an ultrasonic and hydrothermal method.

3. The production method according to claim 2, wherein the co-catalyst is PdS nanoparticles; the preparation method of the PdS nano-particles comprises the following steps:

the palladium source is selected from one or more of palladium dichloride, palladium nitrate, palladium acetate and palladium tetrachloride; the sulfur source is selected from one or more of sulfur powder, thiourea and sodium sulfide.

4. The method of claim 2, wherein the CdSe are introduced into the reaction chamber_1-xTe_xThe nanowires were prepared as follows:

5. The preparation method according to claim 2, wherein in the step A), the temperature of the hydrothermal reaction is 140-180 ℃, the temperature rise rate is 5-10 ℃/min, and the time is 6-18 h.

6. The method according to claim 2, wherein in step A), the CdSe is prepared_1-xTe_xThe content of the RGO in the/RGO composite nano material is 0.1-2 wt%.

7. The preparation method of claim 2, wherein in the step B), the temperature of the hydrothermal reaction is 140 ℃ to 180 ℃, the temperature rise rate is 5 ℃/min to 10 ℃/min, and the time is 6 h to 18 h; the hydrothermal reaction is carried out in a reaction kettle.