CN-122006755-A - Photocatalyst with space ordered supported double cocatalysts, preparation method and application thereof

Abstract

The invention discloses a photocatalyst with a double-catalyst supported in a spatially ordered manner, and a preparation method and application thereof, and belongs to the technical field of photocatalytic materials. The photocatalyst for carrying the double cocatalysts spatially and orderly comprises a basic photocatalyst, an oxidation cocatalyst and a reduction cocatalyst, wherein the oxidation cocatalyst and the reduction cocatalyst are synchronously deposited on the basic photocatalyst, and the basic photocatalyst is a chlorine-oxygen compound. The built-in electric field formed by utilizing the charge separation characteristic among the crystal faces of the basic photocatalyst promotes the directional separation and migration of photo-generated carriers, and remarkably improves the photocatalytic oxygen production activity. The photocatalyst of the invention with the double cocatalysts supported in space order shows excellent oxygen generating performance in the redox medium containing [ Fe (CN) 6 ] 3‑ and [ Fe (CN) 6 ] 4‑ .

Inventors

• CHEN SHANSHAN
• SHI YAWEN
• WANG SHUO

Assignees

• 南开大学

Dates

Publication Date

20260512

Application Date

20260126

Claims (10)

1. 1. The photocatalyst is characterized by comprising a base photocatalyst, an oxidation promoter and a reduction promoter, wherein the oxidation promoter and the reduction promoter are synchronously deposited on the base photocatalyst; The basic photocatalyst is a chlorine-oxygen compound.
2. 2. The spatially-ordered supported co-catalyst of claim 1, wherein the chloroxide compound comprises at least one of Bi 4 XO 8 Cl, doped Bi 4 XO 8 Cl, wherein X is Ta or Nb; And/or the oxidation promoter is at least one of CoO x 、MnO x 、IrO 2 、RuO 2 、NiO x and Fe modified CoO x ; And/or the reduction promoter is at least one of Au, ru, pt, pd, rh, ni.
3. 3. The photocatalyst of spatially-ordered supported double-promoter according to claim 2, wherein the loading amount of metal ions in the oxidation promoter is 0.2 wt% -1.0 wt%; And/or the loading amount of the reduction promoter is 0.1wt% -0.4 wt%.
4. 4. The method for preparing the photocatalyst with the spatially ordered supported double-promoter according to any one of claims 1 to 3, which is characterized by comprising the following steps: (1) Dispersing a basic photocatalyst in a phosphate buffer solution containing K 3 [Fe(CN) 6 ], then adding an oxidation promoter source and a reduction promoter source into the system, and carrying out ultrasonic treatment to obtain a dispersion system; (2) And (3) irradiating the dispersion system in the step (1) under a xenon lamp to obtain the photocatalyst with the space-ordered supported double cocatalysts.
5. 5. The method according to claim 4, wherein the concentration of the phosphate buffer in the step (1) is 25 mmol/L, and the pH of the phosphate buffer is 6; And/or the concentration of K 3 [Fe(CN) 6 in the phosphate buffer containing K 3 [Fe(CN) 6 in the step (1) is 0.1 mmol/L-0.5 mmol/L, preferably 0.3 mmol/L; And/or, in the step (1), the mass ratio of the metal ions in the base photocatalyst, the oxidation promoter source and the reduction promoter source is 100 (0.2-1): 0.1-0.4.
6. 6. The method of claim 4, wherein the power of the xenon lamp in the step (2) is 300W, and the illumination time in the step (2) is 1 h to 3 h.
7. 7. Use of the spatially ordered supported co-catalyst according to any one of claims 1 to 3 or the spatially ordered supported co-catalyst prepared by the preparation method according to any one of claims 4 to 6 in a photocatalytic reaction in the presence of a redox mediator.
8. 8. The use according to claim 7, wherein the redox mediators are [ Fe (CN) 6 ] 3- and [ Fe (CN) 6 ] 4- .
9. 9. The use according to claim 7, wherein the photocatalytic reaction is a photocatalytic decomposition of water to oxygen reaction.
10. 10. Use of the spatially ordered supported co-catalyst according to any one of claims 1 to 3 or the spatially ordered supported co-catalyst prepared by the preparation method according to any one of claims 4 to 6 in the degradation of contaminants.

Description

Photocatalyst with space ordered supported double cocatalysts, preparation method and application thereof Technical Field The invention belongs to the technical field of photocatalytic materials, and particularly relates to a photocatalyst for carrying double cocatalysts in a spatially ordered manner, and a preparation method and application thereof. Background Photocatalytic decomposition of water is one of the potential approaches to solve the energy crisis and environmental pollution problems. Wherein, the photocatalytic water oxidation half reaction (i.e. oxygen generating reaction, OER) has slow kinetics due to the four electron transfer process involved, which becomes a fast step of the whole water splitting process. In order to improve the photocatalytic oxygen production performance, a promoter is generally modified on the surface of the photocatalyst so as to promote the separation and migration of photogenerated carriers and provide effective reaction sites. Currently, most research is focused on supporting a single cocatalyst on the photocatalyst surface to enhance its photocatalytic activity. However, a single cocatalyst generally promotes only one type of oxidation or reduction reaction, and it is difficult to simultaneously realize efficient separation and utilization of holes and electrons, which limits further improvement of photocatalytic efficiency. In addition, the conventional cocatalyst loading method, such as a dipping-calcining method or a physical adsorption method, often has the problems of uneven distribution, weak binding force, shielding of active sites and the like, and influences the overall performance of the catalyst. In recent years, photocatalysts with inter-crystal plane charge separation characteristics have been attracting attention because of their built-in electric fields existing between different crystal planes, which can drive photo-generated electrons and holes to directionally migrate, thereby enhancing charge separation efficiency. For example, li Can et al reported that selective deposition of a promoter on a specific crystal plane was effective in enhancing the photocatalytic water oxidation performance of BiVO 4 (Nature Communications, 1432 (2013)). However, the existing methods focus on the selective loading of a single promoter, and the research on achieving spatially ordered oxidation and reduction of the dual promoter loading on the photocatalyst and making it efficient and synergistic in the redox medium is still relatively lacking. Particularly, in a system using [ Fe (CN) 6]3- as an electron acceptor, the existing research is focused on BiVO 4 materials, so that the types of photocatalysts which can be used for oxygen half-reaction under the system are very limited, and related systematic research is still relatively deficient. Therefore, a novel photocatalytic material capable of realizing high-efficiency and stable oxygen production in the oxidation-reduction mediums of [ Fe (CN) 6]3- and [ Fe (CN) 6]4- is developed, and has important research significance and application potential. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide a photocatalyst for carrying double cocatalysts in a spatially ordered manner, and a preparation method and application thereof. The invention promotes the separation and directional migration of the photo-generated carriers by utilizing a built-in electric field formed by potential differences existing between different crystal faces of the photocatalyst, thereby realizing the selective loading of reduction and oxidation cocatalysts in the areas of the electron and hole collecting surfaces respectively by photo-deposition and remarkably improving the charge separation capability of the photocatalyst. Meanwhile, due to ordered distribution of active sites at different crystal faces, oxidation-reduction reactions occurring on the surface of the photocatalyst are more independent, and the improvement of the photocatalytic oxygen production performance can be further realized. In order to achieve the aim, the technical scheme adopted by the invention is that on one hand, the invention provides a photocatalyst for carrying double cocatalysts in a spatially ordered manner, which comprises a basic photocatalyst, an oxidation cocatalyst and a reduction cocatalyst, wherein the oxidation cocatalyst and the reduction cocatalyst are synchronously deposited on the basic photocatalyst; The basic photocatalyst is a chlorine-oxygen compound. Further, the chlorine-oxygen compound comprises at least one of Bi 4XO8 Cl and doped Bi 4XO8 Cl, wherein X is Ta or Nb; And/or the oxidation promoter is at least one of CoO x、MnOx、IrO2、RuO2、NiOx and Fe modified CoO x; And/or the reduction promoter is at least one of Au, ru, pt, pd, rh, ni. Further, the loading of the metal ions in the oxidation promoter is 0.2 wt% -1.0 wt% (loading=mass of metal ions in the oxidation promoter/mass of the base photoc