CN-121988406-A - Zinc cadmium sulfide/titanium dioxide composite material, preparation method thereof and application of composite photo-anode in hydrogen sulfide photoelectrocatalytic decomposition

Abstract

The invention belongs to the technical field of photoelectrocatalysis and environmental treatment, and particularly relates to a zinc cadmium sulfide/titanium dioxide composite material, a preparation method thereof and application of the composite material serving as a composite photo-anode in photoelectrocatalytic decomposition of hydrogen sulfide. The zinc cadmium sulfide/titanium dioxide composite material provided by the invention comprises an anatase phase TiO 2 nanotube array arranged on the surface of a conductive substrate, and CdZnS nano particles deposited on the anatase phase TiO 2 nanotube array. The zinc sulfide/titanium dioxide composite material provided by the invention is applied to the photoelectrocatalytic decomposition of hydrogen sulfide as a composite photo-anode, has high catalytic activity, high stability and high product selectivity, realizes synchronous H 2 generation and H 2 S detoxification, and does not need complex separation steps. The invention provides a novel material design strategy for a high-performance PEC-H 2 S conversion system and provides technical insight for green resource utilization of sulfide pollutants.

Inventors

• LIU ENZHOU
• WANG WENQI
• HU HAOBIN
• GAO TING
• Tian Jingzhuo
• MA XINYI
• SUN TAO
• LI QIUJIE

Assignees

• 西北大学
• 陇东学院

Dates

Publication Date

20260508

Application Date

20260327

Claims (10)

1. 1. The zinc cadmium sulfide/titanium dioxide composite material is characterized by comprising an anatase phase TiO 2 nano-tube array arranged on the surface of a conductive substrate and CdZnS nano-particles deposited on the anatase phase TiO 2 nano-tube array.
2. 2. The zinc cadmium sulfide/titanium dioxide composite material according to claim 1 is characterized in that the conductive substrate is a titanium sheet, the anatase phase TiO 2 nanotube array grows from TiO 2 nanotubes in a vertical array shape and is attached to the surface of the conductive substrate, a gap structure exists between any two adjacent TiO 2 nanotubes, and the diameter distribution range of the TiO 2 nanotubes is 150-200 nm.
3. 3. The zinc cadmium sulfide/titanium dioxide composite material according to claim 2, wherein the CdZnS nanoparticles are uniformly dispersed in the top end, the inside of a tube cavity and a gap structure among the TiO 2 nanotubes in the form of sphere-like nanoparticles, and the average particle size of the CdZnS nanoparticles is 50-80 nm.
4. 4. A cadmium zinc sulfide/titanium dioxide composite material according to claim 1 or 3, wherein the CdZnS nanoparticle is a Cd 0.5 Zn 0.5 S nanoparticle.
5. 5. The method for preparing the zinc cadmium sulfide/titanium dioxide composite material according to any one of claims 1 to 4, which is characterized by comprising the following steps: taking the conductive substrate as an anode, and placing the conductive substrate and the cathode in a first electrolyte together to perform first anodic oxidation to obtain a first treatment anode; the first treatment anode and the cathode are placed in a second electrolyte together to carry out second anodic oxidation, so that an initial semi-finished product is obtained; Calcining the initial semi-finished product to obtain a semi-finished product, wherein the semi-finished product comprises a conductive substrate and an anatase phase TiO 2 nanotube array arranged on the surface of the conductive substrate; and immersing the semi-finished product in a CdZnS precursor suspension for hydrothermal reaction to obtain the zinc-cadmium sulfide/titanium dioxide composite material, wherein the CdZnS precursor suspension comprises a zinc source, a cadmium source and a sulfur source.
6. 6. The preparation method of the catalyst according to claim 5, wherein the first electrolyte comprises NH 4 F, water and ethylene glycol, the dosage ratio of NH 4 F, water and ethylene glycol in the first electrolyte is (0.5-0.6) g (1-3) mL (95-100) mL, and the first anodic oxidation condition comprises that the temperature is 35-45 ℃, the direct current voltage is 55-65V, and the reaction time is 1-2 h; The second electrolyte comprises NH 4 F, water and glycerol, the dosage ratio of NH 4 F, water and glycerol in the second electrolyte is (0.5-0.6) g (25-35) mL (65-75) mL, the second anodic oxidation condition comprises that the temperature is 35-45 ℃, the direct current voltage is 35-45V, and the reaction time is 3-5 h.
7. 7. The preparation method of the CdZnS precursor suspension is characterized in that the CdZnS precursor suspension comprises a water-soluble zinc salt, a water-soluble cadmium salt, water, inorganic strong base and thioacetamide, the molar ratio of the water-soluble zinc salt to the water-soluble cadmium salt is 1:1, the pH value of the CdZnS precursor suspension is 7.5-14, the temperature of the hydrothermal reaction is 175-185 ℃, and the heat preservation time is 12-36 h.
8. 8. The use of the zinc cadmium sulfide/titanium dioxide composite material according to any one of claims 1-4 or the zinc cadmium sulfide/titanium dioxide composite material prepared by the preparation method according to any one of claims 5-7 as a composite photo-anode in the photoelectrocatalytic decomposition of hydrogen sulfide.
9. 9. A photoelectrocatalysis system for utilizing hydrogen sulfide resources is characterized by comprising an anode chamber and a cathode chamber, wherein the anode chamber and the cathode chamber are separated by a proton exchange membrane, a photoanode and an anolyte which are arranged in the anode chamber, and a cathode and a catholyte which are arranged in the cathode chamber, wherein the photoanode is the zinc cadmium sulfide/titanium dioxide composite material according to any one of claims 1-4 or the zinc cadmium sulfide/titanium dioxide composite material prepared by the preparation method according to any one of claims 5-7, and the anolyte contains I - .
10. 10. A method of photoelectrocatalysis for the utilization of hydrogen sulfide resources, characterized in that the reaction is carried out using the photoelectrocatalysis system for the utilization of hydrogen sulfide resources as claimed in claim 9, comprising the steps of: And (3) receiving visible light irradiation from the anode chamber under the condition of externally applied bias, and when I 3 - is generated in the anode chamber, introducing H 2 S gas into the anode chamber to react, obtaining hydrogen in the cathode chamber and obtaining elemental sulfur in the anode chamber.

Description

Zinc cadmium sulfide/titanium dioxide composite material, preparation method thereof and application of composite photo-anode in hydrogen sulfide photoelectrocatalytic decomposition Technical Field The invention belongs to the technical field of photoelectrocatalysis and environmental treatment, and particularly relates to a zinc cadmium sulfide/titanium dioxide composite material, a preparation method thereof and application of the composite material serving as a composite photo-anode in photoelectrocatalytic decomposition of hydrogen sulfide. Background Hydrogen sulfide (H 2 S) is a highly toxic and highly corrosive gas, is widely generated in industrial processes such as natural gas purification, petroleum refining, coal gasification, biomass pyrolysis and the like, is a main byproduct in the industrial production, and is discharged in a large amount to seriously damage the ecological environment and greatly threaten the health of human bodies. Harmless treatment and resource utilization of H 2 S become industry problems to be solved urgently. From the perspective of resource recovery, the H 2 S molecule contains 6wt% of hydrogen element and 94wt% of sulfur element, can be converted into clean energy hydrogen (H 2) and high-value elemental sulfur (S), and has extremely high recycling potential. Thermodynamic data show that standard gibbs free energy Δg 0=33.2kJ·mol-1 and standard enthalpy change Δh 0=20.4kJ·mol-1 of H 2 S decomposition are far superior to water splitting reaction (Δg 0=237kJ·mol-1), and have thermodynamic advantage of sustainable conversion under mild conditions. Therefore, how to realize synchronous detoxification and resource conversion of H 2 S in a mild, green and low-energy consumption manner has become an important research topic and technical challenge in the current energy and environment fields. At present, the existing H 2 S treatment technology has obvious limitations, and the core requirements of high efficiency, low consumption and no secondary pollution in industrial large-scale application are difficult to meet: 1. the traditional Claus process has the advantages that H 2 S is converted into elemental sulfur through a two-step high-temperature reaction at 800-1200 ℃, SO that the energy consumption is extremely high, secondary pollutants such as SO 2 and the like are easy to generate in the reaction process, and the method does not accord with the environmental-friendly industry development trend; 2. The plasma decomposition technology relies on special equipment with complex structure, the equipment investment and the later operation cost are high, and the low-cost large-scale application is difficult to realize; 3. The electrochemical decomposition method is to continuously input external electric energy to drive the reaction, so that the cost of hydrogen production is greatly increased, and the economic value of H 2 S resource conversion is weakened; 4. The photocatalysis technology can utilize solar energy to drive H 2 S to decompose, has the advantage of low energy consumption, but the traditional single semiconductor catalyst has obvious defects that, for example, cdS is easy to generate serious photo-corrosion, the stability of the catalyst is insufficient, the band gap of TiO 2 is wider (about 3.2 eV), only the ultraviolet light region accounting for 4% of the solar spectrum can be responded, the photo-generated electron-hole pair recombination rate is high, and the catalytic efficiency and the practical application scene are severely limited. In recent years, the development of Photoelectrocatalysis (PEC) technology provides a new technological approach for H 2 S resource conversion. The technology utilizes the photoelectrode to absorb sunlight to generate photo-generated electron-hole pairs, can drive H 2 S to decompose at normal temperature and normal pressure, has the advantages of mild reaction conditions, controllable process and easy coupling with renewable energy sources such as solar energy, and is expected to break through the limitation of the traditional technology. However, the current PEC-H 2 S conversion system still faces a key technical bottleneck, and the industrial application of the system is restricted, namely, the photo-anode is easy to be passivated by sulfur species generated in the reaction process, so that the catalytic activity is fast attenuated, the stability is poor, and meanwhile, the catalytic activity of the photo-anode is low and the selectivity is poor. Disclosure of Invention The invention aims to provide a zinc cadmium sulfide/titanium dioxide composite material, a preparation method thereof and application of the composite material as a composite photo-anode in hydrogen sulfide photoelectrocatalytic decomposition, the method has high catalytic activity, high stability and high product selectivity, solves the problems of low carrier separation efficiency and poor sulfur passivation resistance of the photoelectrode in the prior ar