TWI470120B - Method of prepareing titanium tube array photoelectrode - Google Patents

Description

Photocatalyst titanium tube array electrode manufacturing method

The invention relates to a photocatalytic titanium tube array electrode manufacturing method, which is used for solar power generation to generate photocurrent and hydrogen.

At present, the water splitting cell hydrogen production reactor for water decomposition and hydrogen production is mainly in two forms, one is single cell or undivided cell, that is, the anode and the yang are not separated. The other is a double cell or a split cell, that is, the cathode and the cation are separated by a suitable separation membrane.

Among them, the single-tank type often uses a photocatalyst suspension to generate water decomposition. Although it is simple in operation, it cannot separate the hydrogen and oxygen generated by water decomposition, causing operational danger, and cannot generate hydrogen as fuel. use efficiently. Therefore, sacrificial reagents such as methanol and sodium sulfite are often used to suppress the formation of oxygen. The use of a sacrificial reagent tends to produce by-products in the water decomposition reaction, and thus cannot be effectively used in a process in which water is decomposed to produce a large amount of hydrogen. The double-tank type is safe for operation because it can effectively separate hydrogen and oxygen, and is more suitable for practical hydrogen production applications.

U.S. Patent No. 4,332,650 discloses a method of generating hydrogen and oxygen from water by electrochemical processes; U.S. Patent 6,728,893 B2 discloses a device and method for separating hydrogen and oxygen produced by water decomposition using a membrane.

In general, a photoelectrochemical hydrogen production reactor must include a photoanode that receives light and a cathode that is made of platinum catalyst. The photocatalyst film electrode applied to the separable hydrogen production reactor can be divided into a powder catalyst mixed with an adhesive to form a film electrode or a thin film electrode prepared by sputtering or evaporation. Among them, the sequenced thin film electrodes are more conducive to electron-hole separation and electron transfer, which will effectively improve the hydrogen production efficiency. In an aqueous solution, when an anode catalyst, such as titanium dioxide (TiO ₂ ), is irradiated with a light source of a specific wavelength (hv) to excite electrons and holes, the hole can decompose water molecules to generate oxygen and hydrogen ions, and electrons are transmitted. Hydrogen is generated by reduction to the cathode and hydrogen ions to generate hydrogen.

Photocatalyst array electrodes play an important role in the water decomposition and hydrogen production reaction. Therefore, an efficient separation of electron-hole pairs of photocatalyst array electrodes also plays an important role in hydrogen separable hydrogen production reactors.

Photocatalyst electrodes have been developed in a variety of ways, such as vacuum sputtering, evaporation, anodizing, and sol-gel coating. At present, an anodized array photocatalyst electrode and a metal platinum (Pt) pair electrode substrate are prepared. However, the photo-electric current of the titanium dioxide photocatalyst array electrode prepared by the anodic oxidation method is not ideal, and the photocatalyst adhesion amount is low, and the water decomposition effect is also poor, which is difficult to achieve the goal of commercial application.

In view of the fact that the conventional techniques cannot meet the needs of the user in actual use, in order to solve the disadvantages of the conventional use, the present invention proposes to directly prepare an array of titanium tubes by anodization, by changing the anodizing time, the concentration of the anolyte and the calcination. Time is combined with a separable water-decomposition hydrogen production reactor, which has a very high production of hydrogen.

In view of the fact that the conventional techniques cannot meet the needs of the user in actual use, in order to solve the disadvantages of the conventional use, the present invention proposes to directly prepare an array of titanium tubes by anodization, by changing the anodizing time, the concentration of the anolyte and the calcination. Time is combined with a separable water-decomposition hydrogen production reactor, which has a very high production of hydrogen.

In one embodiment, the present invention provides a photocatalytic titanium tube array electrode manufacturing method comprising the steps of: providing a titanium metal sheet having a thickness of about 0.127 mm and having a purity of about 99.7%; and cutting the titanium metal sheet into Rectangular or square, and combined with a copper sheet to form an electrode sheet; an electrolyte solution is prepared, which is formed by adding 10-30% by weight of ammonium fluoride and 10% by weight of deionized water to ethylene glycol; The electrode sheet is placed in the electrolyte as an anode, and a copper piece is placed in the electrolyte as a cathode, and an anodizing reaction is carried out for 5 to 120 minutes at a reaction temperature of 25 to 80 degrees by a voltage of 20 to 60 V. And stirring the electrolyte to maintain the stability of the concentration; taking out the electrode sheet, carefully washing it with deionized water and then drying it; placing the electrode sheet in a high temperature furnace and calcining at 450-550 degrees Celsius for 30 to 240 minutes, A photocatalyst titanium tube array electrode is formed.

In another embodiment, the present invention provides a hydrogen-producing reactor using the photocatalyst titanium tube array electrode of the present invention, a hydrogen-producing reactor 2 using a photocatalyst titanium tube array electrode, the structure comprising: a first transparent sheet The material is quartz glass; a first fixing seat is disposed on the first transparent sheet, and includes an inlet and outlet for replacing the reaction solution; and a reaction plate aid is disposed on the first fixing seat, For fixing a double-sided electrode, one side of which is an anode, and the other side is a cathode, the anode is a photocatalyst titanium tube array electrode, the cathode is the nano platinum film; and a leak stop ring is disposed on the reaction piece The auxiliary device comprises a fixed proton exchange membrane; a second fixing seat is disposed on the leakage ring, and includes an inlet and outlet for replacing the reaction solution; and a second transparent sheet is disposed on the second On the fixing base, the material is quartz glass.

The photocatalyst titanium tube array electrode of the invention has the high specific surface area and the ability to rapidly transfer electrons, and can also reduce the recombination of electron-holes, thereby improving the intensity of the photocurrent and improving the hydrogen production efficiency.

The technical means and efficacy of the present invention for achieving the object will be described below with reference to the accompanying drawings, and the embodiments listed in the following drawings are only for the purpose of explanation, and are to be understood by the reviewing committee, but the technical means of the present invention are not Limited to the listed figures.

Please refer to FIG. 1A again, and please also refer to the schematic diagram of the photocatalyst titanium tube array electrode preparation device of FIG. 1B for better understanding. FIG. 1A is a flow chart of a photocatalyst titanium tube array electrode manufacturing method, which comprises the following steps: First, step 10 is performed to provide a titanium metal sheet having a thickness of about 0.127 mm and a purity of about 99.7%. After step 10, step 11 is performed to cut the titanium metal sheet into a rectangle or a square (this invention is 4 cm× 4 cm), and combined with the copper sheet to form an electrode sheet; after step 11, step 12 is carried out to prepare an electrolyte solution, which is 10 to 30 wt% (20% in this embodiment) of ammonium fluoride, 10wt% of deionized water is added to the ethylene glycol; after step 12, step 13 is performed, the electrode sheet is placed in the electrolyte as an anode, and a copper sheet is placed in the electrolyte as a cathode, which is passed through 20~ The voltage of 60 V (20 V in this embodiment) is anodized for 5 to 120 minutes (120 minutes in this embodiment) at a reaction temperature of 25 to 80 degrees Celsius (25 degrees Celsius in this embodiment), and the mixture is stirred. The electrolyte is maintained to maintain its concentration stable; after step 13, step 14 is performed The electrode sheet is carefully cleaned with deionized water and then dried. After step 14, step 15 is performed, and the electrode sheet is placed in a high temperature furnace at a temperature of 450 to 550 degrees Celsius (500 degrees Celsius in this embodiment). 240 minutes (120 minutes in this example) to form a photocatalyst titanium tube array electrode (t-TiO ₂ ).

Wherein, after step 15, the method further comprises the step of: combining the photocatalyst titanium tube array electrode and a nanometer platinum film to form a double-sided electrode, one side of which is an anode and the other side is a cathode, and the anode is photocatalyst titanium. A tube array electrode, the cathode being the nano platinum film.

Referring to FIG. 2 again, it is a flow chart of a conventional photocatalyst titanium tube array electrode manufacturing method, which comprises the following steps: First, step 20 is provided to provide a titanium metal sheet having a thickness of about 0.127 mm and a purity of about 99.7. %; after step 20, step 21 is performed, the titanium metal sheet is cut into a size of 4 cm × 4 cm, and combined with the copper sheet to form an electrode sheet; after step 21, step 22 is performed, and P25 powder and 20 wt% are all Fluoropolystyrenesulfonic acid (Nafion) is mixed at a ratio of 1:5 and then coated on the electrode plate; after step 22, step 23 is performed, the electrode plate is calcined at 80 degrees Celsius, and more solvent is removed. Forming a photocatalyst titanium tube array electrode; after step 23, performing step 24: combining the photocatalyst titanium tube array electrode with a nanometer platinum film to form a double-sided electrode having one anode on one side and a cathode on the other side, The anode is a photocatalyst titanium tube array electrode, and the cathode is the nano platinum film.

Referring to FIG. 3 again, it is a schematic diagram of a hydrogen-producing reactor using the photocatalyst titanium tube array electrode of the present invention, and a hydrogen-producing reactor 2 using a photocatalyst titanium tube array electrode, the structure of which includes: a transparent sheet 30, the material of which is quartz glass; a first fixing seat 31 is disposed on the first transparent sheet 30, and includes an inlet and outlet for replacing the reaction solution; a reaction piece assisting device 32 is provided The first fixing base 31 is configured to fix a double-sided electrode, one side of which is an anode, and the other side is a cathode, the anode is a photocatalyst titanium tube array electrode, and the cathode is the nano platinum film; The leakage ring 33 is disposed on the reaction aid 32 and includes a fixed proton exchange membrane. A second fixing seat 34 is disposed on the leakage ring 33 and includes an inlet and outlet for replacing the reaction solution. A second transparent sheet 35 is disposed on the second fixing base 34, and the material thereof is quartz glass.

Referring to FIG. 4 and FIG. 5 again, the photocurrent test chart of the photocatalyst titanium array electrode of the conventional and the present invention is used, and the AM 1.5 standard solar light source is used in the potassium hydroxide concentration of 1 M at room temperature. Irradiation with silver/silver chloride (Ag/AgCl) as the reference electrode and scanning speed of 50 mV/s. As can be seen from the figure, the photocurrent generated by the conventional photocatalyst titanium array electrode is 0.5 mA/cm ² , and the photocatalytic titanium tube array electrode of the present invention has a photocurrent intensity of 6.7 mA/cm ² , which is the conventional photocatalyst titanium. The tube array electrode is more than 13 times, so this experiment proves that the photocatalyst titanium tube array electrode of the present invention has the effect of generating extremely high photocurrent.

Referring to Table 1, the hydrogen production comparison table of the photocatalyst titanium tube array of the present invention and the conventional one is used, and 50 ml of a 0.5 wt% aqueous ethanol solution is added to the hydrogen production reaction using the photocatalyst titanium tube array electrode of the present invention. In the device, the temperature is fixed at 25 degrees Celsius, the system is first flushed with 99.99% pure argon for more than 15 minutes to determine the air in the system, and the sunlight source system is covered by the light source. The reaction time is set as the reaction start time. (t = 0), using a drainage gas collection method at the outlet of one end of the reactor, the reaction was continuously carried out for 1 hour, and the generated gas was collected. After the reaction was completed, the mask was closed, and the collected gas was analyzed by gas chromatograph (Gas Chromatography, China Chromatography) on a chromatography column MS-5A to confirm the gas generation. As can be seen from the table, the photocatalyst titanium tube array electrode of the present invention can efficiently generate hydrogen gas at normal temperature and sunlight.

However, the above description is only for the embodiments of the present invention, and the scope of the invention is not limited thereto. That is, the equivalent changes and modifications made in accordance with the claims of the present invention should still fall within the scope of the patent of the present invention. I would like to ask your review committee to give a clear understanding and pray for it.

30. . . First transparent film

31. . . First mount

32. . . Reaction aids 32

33. . . Stop leak ring

34. . . Second mount

35. . . Second transparent film

Figure 1A is a flow chart of a method for fabricating a photocatalyst titanium tube array electrode

Figure 1B is a schematic diagram of a photocatalyst titanium tube array electrode preparation device

Figure 2 is a flow chart of the conventional photocatalytic titanium tube array electrode fabrication method.

Figure 3 is a schematic view showing the structure of a hydrogen-producing reactor using the photocatalyst titanium tube array electrode of the present invention.

Figure 4 is a photocurrent test diagram of a conventional photocatalyst titanium array electrode

Figure 5 is a photocurrent test diagram of the photocatalyst titanium array electrode of the present invention.

Claims (9)

A photocatalyst titanium tube array electrode manufacturing method comprising the steps of: providing a titanium metal sheet; cutting the titanium metal sheet into a rectangle or a square, and combining with the copper sheet to form an electrode sheet; and formulating an electrolyte, the electrolyte 10 to 60 wt% of ammonium fluoride and 1 to 50 wt% of deionized water are added to ethylene glycol; the electrode sheet is placed in the electrolyte as an anode, and a copper piece is placed in the electrolyte as The cathode is anodized at a reaction temperature of 25 to 80 degrees Celsius for 5 to 120 minutes at a reaction temperature of 5 to 60 V, and the electrolyte is stirred to maintain its concentration stable; the electrode piece is taken out and carefully treated with deionized water. After washing, it is dried in the shade; the electrode sheet is placed in a high temperature furnace and calcined at 500 degrees Celsius for 30 to 240 minutes to form a photocatalyst titanium tube array electrode. The photocatalyst titanium tube array electrode manufacturing method according to claim 1, wherein the photocatalyst titanium tube array electrode is combined with a nano platinum film to form a double-sided electrode. It is an anode, and the other side is a cathode. The anode is a photocatalyst titanium tube array electrode, and the cathode is the nano platinum film. The photocatalyst titanium tube array electrode manufacturing method according to the first or second aspect of the invention, wherein the titanium metal sheet is cut to have a size of 4 cm × 4 cm. The photocatalyst titanium tube array electrode manufacturing method according to claim 1 or 2, wherein the electrolyte is fluorinated by 20% by weight. Ammonium, 10% by weight of deionized water was added to the ethylene glycol to form. A method for fabricating a photocatalyst titanium tube array electrode according to claim 1 or 2, wherein the voltage of the anodization reaction is 20V. The photocatalytic titanium tube array electrode manufacturing method according to claim 5, wherein the reaction time of the anodizing reaction is 120 minutes. The photocatalyst titanium tube array electrode manufacturing method according to the first or second aspect of the invention, wherein the calcination time is 120 minutes. A hydrogen-producing reactor using the photocatalyst titanium tube array electrode according to claim 1, comprising: a first transparent sheet; a first fixing seat disposed on the first transparent sheet, including one available To replace the inlet and outlet of the reaction solution; a reaction plate aid is disposed on the first fixing base for fixing a double-sided electrode, one side of which is an anode and the other side is a cathode, and the anode is photocatalyst titanium a tube array electrode, the cathode is the nano platinum film; a leak stop ring is disposed on the reaction plate aid, and includes a fixed proton exchange film; a second fixing seat is disposed on the leakage ring , comprising an inlet and outlet for replacing the reaction solution; and a second transparent sheet disposed on the second fixing seat. A hydrogen-producing reactor using a photocatalyst titanium tube array electrode according to claim 9, wherein the material of the first transparent sheet and the second transparent sheet is quartz glass.