Preparation method of metal oxide semiconductor heterojunction photocatalyst

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst Technical field

The present invention relates to a kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, belongs to the technical field of semiconductor heterojunction photocatalyst preparation.

Background technique

[0002] Metal oxide semiconductor heterojunction photocatalyst is a simple, convenient, economical and efficient heterojunction photocatalyst that can catalyze and degrade pollutants in air and water to purify the environment.

[0003] However, at present, although the method for preparing a metal oxide semiconductor heterojunction can meet production requirements to varying degrees, there are also some unavoidable problems. For example, there may be high pressure in the hydrothermal reaction process, and improper operation may easily cause explosion hazards; the reaction of incipient wetness impregnation method is time-consuming and complicated, and the cost is high. At the same time, the metal oxide semiconductor heterojunction prepared by these methods is easy to disperse in air and water, which is not conducive to recycling, and it is easy to cause secondary pollution to the environment. Moreover, these methods can only prepare 2-3 kinds of metal oxide semiconductors at the same time, form 1-2 kinds of metal oxide semiconductor heterojunctions, and cannot simultaneously prepare multiple types of multilayer heterostructures in batches, let alone combine multiple The layers of semiconductor heterojunctions are connected into a whole, so as to synergize and enhance the effect. This hinders the practical application and development of metal oxide semiconductor heterojunction photocatalysts. Therefore, there is a need for a simple, efficient, and controllable method to simultaneously prepare various types of photocatalysts that are convenient to recycle and highly efficient in batches.

Contents of the invention

Summary of the invention For the defect or improvement demand that prior art exists, the invention provides a kind of method that utilizes spray pyrolysis to prepare multilayer multiple metal oxide semiconductor heterojunction photocatalyst, metal precursor is passed through dissolution, atomization, Thermal decomposition, oxidation and other processes are deposited on the substrate to form a metal oxide semiconductor film, and then by changing different types of precursor solutions to change the type and number of layers of the metal oxide film, thereby preparing multiple layers of various metal oxides in batches. Material semiconductor heterojunction photocatalyst, and finally use powder metallurgy process to sinter the photocatalyst with porous structure.

To achieve the above object, the present invention adopts the following technical solutions:

A kind of preparation method of metal oxide heterojunction photocatalyst, concrete steps are as follows:

(1) base is placed on the outlet of heating furnace, and heating furnace outlet is sealed;

(2) Transition metal salt precursor solution is injected in atomizer, connects atomization port to the entrance of heating furnace, opens atomizer and controls atomization speed;

(3) Open heating furnace and set heating temperature, atomized liquid drop is through heating furnace heat treatment, deposits metal oxide semiconductor thin film on substrate; Change precursor solution, deposit a kind of metal oxide semiconductor thin film again; So replace once As mentioned above, two or more metal oxides are deposited on the substrate, and by replacing the precursor solution, multiple layers of different types of metal oxide semiconductor films are deposited on the substrate, which is the metal oxide heterojunction photocatalyst.

The substrate described in step (1) is glass, silicon oxide, crystalline silicon, glass fiber cloth, aluminum foil, aluminum oxide, copper foil, nickel foam or polytetrafluoroethylene.

The described precursor solution of step (2) is the solution containing one or more transition metal elements; The concentration of salt is

0.1 TOg/L, the transition metal salt is titanium tetrachloride, silver acetate, acetate, copper acetate, etc., and the solvent is water and/or ethanol.

The atomization speed described in step (2) is 0.017.OL/h.

The temperature of heating furnace heat treatment described in step (3) is 350-800 DEG C.

The total thickness of the metal oxide semiconductor film deposited on the substrate described in step (3) is

The present invention can also utilize powder metallurgy process, the thin film on substrate is sintered into the multilayer metal oxide heterojunction photocatalyst with porous structure, powder metallurgy process sintering temperature is 500-900 °C, and sintering atmosphere pressure is 0.01 IMPa, the sintering atmosphere is nitrogen atmosphere, ammonia atmosphere or mist atmosphere, the holding time is 1-12min, and the heating rate is 10-300 °C/min_o

Described heating furnace is the furnace that contains hollow cavity, as tubular furnace (horizontal or vertical), muffle furnace; Atomizer comprises ultrasonic atomizer, compression atomizer and mesh atomization device.

Compared with prior art, advantage of the present invention is:

The present invention can prepare the metal oxide semiconductor heterojunction photocatalyst of appointed number of layers and kind by controlling the kind of precursor solution, spraying order and times; Also can control by the concentration of precursor solution and consumption Film thickness: The method of the present invention is simple, convenient and has certain versatility, and can realize the deposition of different layers and various types of metal oxide semiconductor heterojunctions on different loads.

The present invention deposits different kinds of metal oxide semiconductors on the same substrate to form multilayer metal oxides of different kinds, and can also utilize powder metallurgy process sintering to form a porous heterojunction photocatalyst, and the overall combination of the catalyst is tight, It has a porous structure, and multi-layers of different types of heterogeneous junctions are integrated into a whole, which works synergistically, is not easy to disperse in the air or water, and is easy to recycle and reuse.

Description of drawings

Fig. 1 is the picture of embodiment 1-4 photocatalyst on each substrate;

Fig. 2 is the catalytic effect figure of embodiment 5 catalyst 5-A and catalyst 5-B and embodiment 6-A, comparative example 1-2 product.

Detailed ways

Embodiment Below by specific embodiment, the present invention is described in further detail, but the present invention is not limited to following specific embodiment.

Embodiment 1

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, concrete steps are as follows:

(1) the aluminum foil base is laid flat and fixed on the nozzle of the vertical tubular furnace; the nozzle of the atomizer is connected to the lower nozzle of the vertical tubular furnace;

(2) under room temperature, 4.24g silver acetate hexahydrate is joined in 2.5L deionized water, magnetic stirring 2h, obtains the precursor solution one that mixes;

Under room temperature, 51nL titanium tetrachloride is added dropwise in the 100mL ethanol of violent stirring, continue to stir 1h to obtain mixed homogeneous solution, slowly add this solution to the 2.8L deionized water of stirring, continue to stir 11h to obtain mixed homogeneous solution Precursor solution two;

Under room temperature, 3.14g copper acetate monohydrate is joined in 2.5L deionized water, magnetic stirring 4h, obtains the precursor solution three that mixes;

Under room temperature, 4.88g manganese acetate trihydrate is joined in 2.5L deionized water, magnetic stirring 3h, obtains the precursor solution 4 that mixes homogeneously;

(3) Add the uniformly mixed precursor solution to the atomizer storage box, open the vertical tube furnace power supply, adjust the heating temperature to 450 ° C, and when the actual temperature reaches 450 ° C, open the atomizer , adjust the atomization speed to 0.5L/h, and carry out atomization deposition;

Treat precursor solution one atomization and finish, the precursor solution two that mixes is added in the material storage box of atomizer, adjust vertical tubular furnace heating temperature to 550 DEG C, when actual temperature reaches 550 DEG C, Turn on the atomizer, adjust the atomization speed to 0.15L/h, and carry out atomization deposition;

Treat that precursor solution two atomization finishes, the precursor solution three that mixes is added in the material storage box of atomizer, adjust vertical tubular furnace heating temperature to 350 DEG C, when actual temperature reaches 350 DEG C, Turn on the atomizer, adjust the atomization speed to 0.3L/h, and carry out atomization deposition;

Treat that precursor solution three atomizations finish, the precursor solution four that mixes is added atomizer storage box, adjust vertical tubular furnace heating temperature to 450 DEG C, when actual temperature reaches 450 DEG C, open mist Nebulizer, adjust the atomization speed to 0.3L/h for atomization deposition;

[0034] After the atomization finishes, the nickel oxide/titanium dioxide/copper oxide/manganese oxide heterojunction photocatalyst loaded on the aluminum foil substrate can be obtained, and the total thickness of the photocatalyst film is about 5um.

Embodiment 2

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, concrete steps are as follows:

(1) the glass substrate is laid flat and fixed on the upper end nozzle of the vertical tube furnace; the atomizer is misted and connected to the lower end nozzle of the vertical tube furnace; (2) under room temperature, 5mL titanium tetrachloride is gradually Add dropwise into vigorously stirred 100mL ethanol, continue to stir for 1h to obtain a uniformly mixed solution, slowly add the solution to stirred 2.8L deionized water, continue to stir for 11h to obtain a uniformly mixed precursor solution 1;

Under room temperature, 8.48g nickel acetate hexahydrate is joined in 2.5L deionized water, magnetic stirring 2h, obtains the precursor solution two that mixes;

Under room temperature, 6.28g copper acetate monohydrate is joined in 2.5L deionized water, magnetic stirring 4h, obtains the precursor solution three that mixes;

(3) Add the homogeneously mixed precursor solution to the material storage box that is atomized; open the vertical tube furnace power supply, adjust the heating temperature to 550 ° C, and when the actual temperature reaches 550 ° C, open the atomizer and adjust The atomization speed is 0.15L/h for atomization deposition;

Treat precursor solution one atomization and finish, the precursor solution two that mixes is added atomizer storage box, adjust vertical tubular furnace heating temperature to 450 DEG C, when actual temperature reaches 450 DEG C, open mist Nebulizer, adjust the atomization speed to 0.25L/h for atomization deposition;

Treat that precursor solution two atomization finishes, the precursor solution three that mixes is added atomizer storage box, adjust vertical tube furnace heating temperature to 350 DEG C, when actual temperature reaches 350 DEG C, open mist Nebulizer, adjust the atomization speed to 0.15L/h for atomization deposition;

[0043] After the atomization finishes, the titanium dioxide/nickel oxide/copper oxide heterojunction photocatalyst loaded on the glass substrate can be obtained, and the total thickness of the photocatalyst film is about 6um.

Embodiment 3

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, concrete steps are as follows:

(1) the fiberglass cloth base is laid flat and fixed on the nozzle of the vertical tube furnace; the nozzle of the atomizer is connected to the lower nozzle of the vertical tube furnace;

(2) under room temperature, 4.24g nickel acetate hexahydrate is joined in 2.5L deionized water, magnetic stirring 2h, obtains the precursor solution one that mixes;

Under room temperature, 5mL titanium tetrachloride is added dropwise in the 100mL ethanol of violent stirring, continue to stir 1h to obtain the solution of mixing homogeneously, this solution is slowly added in the 2.8L deionized water of stirring, continue to stir 11h to obtain mixing homogeneously The precursor solution II;

Under room temperature, 3.14g copper acetate monohydrate is joined in 2.5L deionized water, magnetically stirred 4h, obtains the precursor solution three of mixing;

(3) Add the uniformly mixed precursor solution to the atomizer storage box, turn on the vertical tube furnace power supply, adjust the heating temperature to 450 ° C, and when the actual temperature reaches 450 ° C, turn on the atomizer , adjust the atomization speed to 0.5L/h, and carry out atomization deposition;

Treat precursor solution one atomization and finish, the precursor solution two that mixes is added atomizer material storage box, adjust vertical tubular furnace heating temperature to 550 DEG C, when actual temperature reaches 550 DEG C, open mist Nebulizer, adjust the atomization speed to 0.15L/h for atomization deposition;

Treat that precursor solution two atomizations end, the precursor solution three that mixes is added atomizer storage box; Adjust the heating temperature of vertical tubular furnace to 350 DEG C, when actual temperature reaches 350 DEG C, open mist Nebulizer, adjust the atomization speed to 0.3L/h for atomization deposition;

When the three atomizations of the precursor solution are completed, the precursor solution one of the same amount is added to the atomizer storage box, and the heating temperature of the vertical tube furnace is adjusted to 450° C., and when the actual temperature reaches 450° C., open the mist Nebulizer, adjust the atomization speed to 0.5L/h for atomization deposition;

[0054] After the atomization finishes, the nickel oxide/titanium dioxide/copper oxide/nickel oxide heterojunction photocatalyst loaded on the glass fiber cloth base can be obtained, and the total thickness of the photocatalyst film is about 5um.

Embodiment 4

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, concrete steps are as follows:

(1) the nickel foam base is laid flat and fixed on the nozzle of the vertical tube furnace upper end; the atomizer outlet is connected to the nozzle of the vertical tube furnace lower end;

(2) under room temperature, 5mL titanium tetrachloride is added dropwise in the 100ml ethanol of violent stirring, continue to stir 1h and obtain the solution that mixes, this solution is slowly added in the 2.8L deionized water of stirring, continues to stir 11h Obtain a homogeneously mixed precursor solution 1;

Under room temperature, 4.24g nickel acetate hexahydrate is joined in 2.5L deionized water, magnetic stirring 2h, obtains the precursor solution two that mixes homogeneously,

Under room temperature, 4.88g manganese acetate trihydrate is joined in 2.5L deionized water, magnetic stirring 3h, obtains the precursor solution three that mixes;

(3) Add the uniformly mixed precursor solution to the atomizer storage box, open the vertical tube furnace power supply, adjust the heating temperature to 550 ° C, and when the actual temperature reaches 550 ° C, open the atomizer and adjust The atomization speed is 0.15L/h for atomization deposition;

Treat precursor solution one atomization and finish, the precursor solution two that mixes is added atomizer material storage box, adjust vertical tubular furnace heating temperature to 450 DEG C, when actual temperature reaches 450 DEG C, open mist atomizer, adjust the atomization speed to

0.5L/h, for atomization deposition;

Treat that precursor solution two atomization finishes, the precursor solution one of same amount is added atomizer material storage box, adjust vertical tubular furnace heating temperature to 550 DEG C, when actual temperature reaches 550 DEG C, open mist Nebulizer, adjust the atomization speed to 0.15L/h for atomization deposition;

Treat precursor solution 1 atomization and finish, the precursor solution 3 that mixes is added atomizer material storage box, adjust vertical tubular furnace heating temperature to 450 °C, when actual temperature reaches 450 °C, open mist Nebulizer, adjust the atomization speed to 0.3L/h for atomization deposition;

[0065] After the atomization finishes, the titanium dioxide/nickel oxide/titanium dioxide/manganese oxide heterojunction photocatalyst loaded on the nickel foam substrate can be obtained, and the total thickness of the photocatalyst film is about 6um.

Embodiment 5

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, concrete steps are as follows:

(1) the fiberglass cloth base is laid flat and fixed on the nozzle of the vertical tube furnace; the nozzle of the atomizer is connected to the lower nozzle of the vertical tube furnace;

(2) under room temperature, 5mL titanium tetrachloride is added dropwise in the 100mL ethanol of violent stirring, continue to stir 1h to obtain the solution that mixes homogeneously, this solution is slowly added in the 2.8L deionized water of stirring, continues to stir 11h Obtain a homogeneously mixed precursor solution 1;

Under room temperature, 8.48g nickel acetate hexahydrate is joined in 2.5L deionized water, magnetic stirring 2h, obtains the precursor solution two that mixes;

(3) Add the homogeneously mixed precursor solution to the atomizer storage box, open the vertical tube furnace power supply, adjust the heating temperature to 550 ° C, and when the actual temperature reaches 550 ° C, open the atomizer, adjust The atomization speed is 0.15L/h for atomization deposition;

Treat precursor solution one atomization to finish, the precursor solution two that mixes is added atomizer storage box; Adjust the heating temperature of vertical tubular furnace to 450 DEG C, when actual temperature reaches 450 DEG C, open mist Nebulizer, adjust the atomization speed to 0.25L/h for atomization deposition;

[0073] The titanium dioxide/nickel oxide heterojunction photocatalyst 5-A loaded on the glass fiber cloth base can be obtained after the atomization finishes, and the total thickness of the photocatalyst film is about 4um.

Gained titania/nickel oxide heterojunction photocatalyst A is gently scraped off with a medicine spoon, placed in the quartz crucible country and compacted gently for subsequent use, open the muffle furnace, feed nitrogen, keep the pressure 0.1MPa, set The heating rate was 10°C/min, and the temperature was raised to 800°C. After holding for 10 minutes, the temperature was lowered to room temperature at 5°C/min to obtain a titanium dioxide/nickel oxide heterojunction photocatalyst 5-B with a porous structure.

Embodiment 6

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, concrete steps are as follows:

(1) the fiberglass cloth base is laid flat and fixed on the nozzle of the vertical tube furnace; the nozzle of the atomizer is connected to the lower nozzle of the vertical tube furnace;

(2) under room temperature, 8.48g nickel acetate hexahydrate is joined in 2.5L deionized water, magnetic stirring 2h, obtains the precursor solution one that mixes;

Under room temperature, 5mL titanium tetrachloride is added dropwise in the 100mL ethanol of vigorous stirring, continue to stir 1h and obtain the solution that mixes, this ethanol solution is slowly added in the 2.8L deionized water that stirs, continues to stir 11h to obtain mixing Homogeneous precursor solution II;

Under room temperature, 6.28g copper acetate monohydrate is joined in 2.5L deionized water, magnetically stirred 4h, obtains the precursor solution three that mixes;

(3) Add the homogeneously mixed precursor solution to the atomizer storage box, turn on the vertical tube furnace power supply, adjust the heating temperature to 450°C, and when the actual temperature reaches 450°C, turn on the atomizer and adjust The atomization speed is 0.25L/h for atomization deposition;

Treat precursor solution one atomization to finish, the precursor solution two that mixes is added atomizer storage box; Adjust vertical tubular furnace heating temperature to 550 DEG C, when actual temperature reaches 550 DEG C, open mist Nebulizer, adjust the atomization speed to 0.15L/h for atomization deposition;

Treat that precursor solution two atomization finishes, the precursor solution three that mixes is added atomizer material storage box; Adjust vertical tubular furnace heating temperature to 350 DEG C, when actual temperature reaches 350 DEG C, open mist Nebulizer, adjust the atomization speed to 0.15L/h for atomization deposition;

[0084] After the atomization finishes, the nickel oxide/titanium dioxide/copper oxide heterojunction photocatalyst 6-A supported on the glass fiber cloth base can be obtained, and the total thickness of the catalyst film is about 6um.

Gained nickel oxide/titanium dioxide/copper oxide heterojunction photocatalyst A is gently scraped off with a medicine spoon, placed in the quartz crucible country and compacted gently for subsequent use, open the muffle furnace, feed nitrogen, and keep the pressure at 0.1 MPa, set the heating rate at 300°C/min, raise the temperature to 900°C, keep it warm for 1min, then cool it down to room temperature at 5°C/min to obtain a nickel oxide/titanium dioxide/copper oxide heterojunction photocatalyst 6-B with a porous structure.

Embodiment 7

A kind of preparation method of metal oxide semiconductor heterojunction photocatalyst, concrete steps are as follows:

(1) the glass fiber cloth base is laid flat and fixed on the nozzle of the vertical tube furnace; the nozzle of the atomizer is connected to the lower nozzle of the vertical tube furnace;

(2) under room temperature, 8.48g nickel acetate hexahydrate is joined in 2.5L deionized water, magnetic stirring 2h, obtains the precursor solution one that mixes;

Under room temperature, 5mL titanium tetrachloride is added dropwise in the 100mL ethanol of vigorous stirring, continue to stir 1h to obtain the ethanol solution of mixing, slowly add this ethanol solution to the 2.8L deionized water of stirring, continue to stir for 11h to obtain Mixed homogeneous precursor solution 2;

(3) Add the homogeneously mixed precursor solution to the atomizer storage box, turn on the vertical tube furnace power supply, adjust the heating temperature to 450°C, and when the actual temperature reaches 450°C, turn on the atomizer and adjust The atomization speed is 0.25L/h for atomization deposition;

Treat precursor solution one atomization to finish, the precursor solution two that mixes is added atomizer storage box; Adjust vertical tubular furnace heating temperature to 550 DEG C, when actual temperature reaches 550 DEG C, open mist Nebulizer, adjust the atomization speed to 0.15L/h for atomization deposition;

[0093] The nickel oxide/titanium dioxide heterojunction photocatalyst 7-A supported on the glass fiber cloth substrate can be obtained after the atomization finishes, and the total thickness of the catalyst film is about 4um.

Gained nickel oxide/titanium dioxide heterojunction photocatalyst 7-A is gently scraped off with a medicine spoon, placed in the quartz crucible country and compacted gently for subsequent use, open the muffle furnace, feed nitrogen, and keep the pressure at 0.1MPa , set the heating rate at 200°C/min, raise the temperature to 500°C, keep it warm for 12 minutes, and then cool it down to room temperature at 5°C/min to obtain a nickel oxide/titania heterojunction photocatalyst 7-B with a porous structure.

Comparative example 1

(1) the fiberglass cloth base is laid flat and fixed on the nozzle of the vertical tube furnace; the nozzle of the atomizer is connected to the lower nozzle of the vertical tube furnace;

(2) under room temperature, 4.24g nickel acetate hexahydrate is joined in 2.5L deionized water, magnetically stirred 2h, obtains the precursor solution of mixing; The precursor solution of mixing is added atomizer storage material box;

(3) open the vertical tube furnace power supply, adjust the heating temperature to 450°C, when the actual temperature reaches 450°C, open the atomizer, adjust the atomization speed to be 0.5L/h, and carry out atomization deposition;

[0099] After the atomization finishes, the nickel oxide photocatalyst loaded on the glass fiber cloth base can be obtained, and the thickness of the photocatalyst film is about 1um.

Comparative example 2

(1) the glass fiber cloth base is laid flat and fixed on the nozzle of the vertical tube furnace; the nozzle of the atomizer is connected to the lower nozzle of the vertical tube furnace;

(2) under room temperature, 5mL titanium tetrachloride is added dropwise in the 100mL ethanol that stirs violently, continue to stir 1h to obtain the solution that mixes homogeneously, this solution is slowly added in the 2.8L deionized water that stirs, continues to stir 11h Obtain a uniformly mixed precursor solution; add the uniformly mixed precursor solution to the atomizer storage box;

(3) Open the vertical tube furnace power supply, adjust the heating temperature to 550°C, when the actual temperature reaches 550°C, open the atomizer, adjust the atomization speed to be 0.15L/h, and carry out atomization deposition;

[0104] After the atomization finishes, the titanium dioxide photocatalyst loaded on the glass fiber cloth base can be obtained, and the thickness of the photocatalyst film is about 2um.

Fig. 1 is the picture of embodiment 1-4 photocatalyst on each substrate, as can be seen from the figure, obtained uniform catalyst thin film on substrate.

Photocatalytic test: with 50mL, the methyl orange solution that concentration is 20PPM is placed in beaker, under dark environment, the glass fiber cloth of the catalyzer of 25cm is put into methyl orange solution, dark reaction in dark 30min, reach adsorption equilibrium, use 300W xenon lamp to simulate sunlight irradiation, take a sample every 15min, centrifuge the sample at 8000rpm on a centrifuge for 5min, take the supernatant, test the absorbance of the sample with UV-Vis absorption spectrum, the wavelength is 463nm for formazan Base orange absorbance, its value is related to the concentration of methyl orange, assuming that the absorbance of pure methyl orange solution with a concentration of 20PPM is C0, and the absorbance of the sample methyl orange is Cx (x is the corresponding sampling time), then the sample taken The percentage of the remaining methyl orange in the original amount can be expressed as Cx/C0, and the relationship curve of Cx/C0 and time is recorded as the degradation curve of the catalyst. Fig. 2 is the catalyst 5-A prepared by embodiment 5 and the catalyst 5B and Catalyst 6-A prepared in Example 6 and the catalytic effect diagram of the product of Comparative Example 1-2, it can be seen from the figure that the effect of catalyst B obtained after sintering treatment is better with the extension of time. All samples have good pollutant adsorption and photocatalytic degradation properties, and sintering is more favorable for the degradation of gaseous organic pollutants.