CN-121988401-A - Preparation and application of dye sensitization photocatalyst based on metal polymalocyanine

Abstract

A preparation method and application of a dye sensitization photocatalyst based on metal polymalocyanine relate to the technical fields of photocatalysis materials and new energy. Titanium dioxide (P25) is used as a carrier, metal phthalocyanine (MPPc) is loaded on the surface of the carrier through an in-situ polymerization method, and a terpyridine ruthenium complex (RuP) is further adsorbed as a photosensitizer, so that the ternary composite photocatalyst (RuP-P25-MPPc) is constructed. Under the irradiation of visible light, the catalyst takes N, N-Dimethylformamide (DMF) as a solvent, takes 1, 3-dimethyl-Benzoimidazole (BIH) as a sacrificial agent, and takes phenol as a proton source, so that the catalyst can efficiently catalyze reduction of carbon dioxide into carbon monoxide. The introduction of the metal polymalocyanine effectively improves the charge separation efficiency and provides rich catalytic sites, wherein the catalyst based on the iron polymalocyanine (FePPc) has optimal performance, and the CO generation rate can reach 207 mu mol g ‑1 h ‑1 . The catalyst has the advantages of clear structure and simple preparation method, and is suitable for the field of solar-driven carbon dioxide resource utilization.

Inventors

• LI FEI
• GAO HUA
• LI XIAONA

Assignees

• 大连理工大学

Dates

Publication Date

20260508

Application Date

20260129

Claims (9)

1. 1. A dye sensitized photocatalyst based on metal polymalocyanine, characterized in that the catalyst has a ternary composite structure, comprising: A titanium dioxide carrier; a metal polymalocyanine supported on the surface of the titanium dioxide carrier; and an organic photosensitizer adsorbed on the surface of the titanium dioxide carrier; The metal center in the metal phthalocyanine is at least one selected from Fe, co, ni, cu, zn; the organic photosensitizer is a terpyridyl ruthenium complex modified by a phosphoric acid group, and the structural formula of the terpyridyl ruthenium complex is [ Ru (bpy) 2 (4,4′-(PO 3 H 2 ) 2 bpy)]Cl 2 .
2. 2. The photocatalyst of claim 1, wherein the titanium dioxide is P25 TiO 2 .
3. 3. The photocatalyst of claim 1, wherein the metal center is Fe.
4. 4. A method for preparing a photocatalyst according to any one of claims 1 to 3, comprising the steps of: (1) Loading metal polymalocyanine on the surface of the titanium dioxide carrier by an in-situ polymerization method to obtain an intermediate composite material; (2) And (3) mixing and adsorbing the intermediate composite material obtained in the step (1) and an organic photosensitizer in a solvent to obtain the TiO 2 composite photocatalyst loaded with the metal polymalocyanine.
5. 5. The process of claim 4, wherein the in situ polymerization in step (1) is selected from the group consisting of melt in situ polymerization.
6. 6. The method according to claim 5, wherein the melt in-situ polymerization is carried out by mixing and grinding titanium dioxide, pyromellitic anhydride, urea and metal salt, and melt polymerizing at 200-240 ℃ for 2-4 hours.
7. 7. Use of a photocatalyst according to any one of claims 1-3 in a photocatalytic carbon dioxide reduction reaction.
8. 8. The use according to claim 7, wherein the photocatalytic carbon dioxide reduction reaction is carried out under the following conditions: The solvent is N, N-dimethylformamide, the electron sacrificial agent is 1, 3-dimethyl benzoimidazole, the proton source is phenol, and the illumination condition is visible light or white light with the wavelength of more than 400 nm.
9. 9. The use according to claim 7, wherein in the photocatalytic carbon dioxide reduction reaction, the catalyst: the dosage ratio of N, N-dimethylformamide to 1, 3-dimethyl-benzoimidazole to phenol is (1-10) mg (5-30) mL (0.02-3) mmol (0.5-10) mmol.

Description

Preparation and application of dye sensitization photocatalyst based on metal polymalocyanine Technical Field The invention belongs to the technical field of photocatalytic materials and new energy, and particularly relates to a dye sensitization type hybrid photocatalyst for reducing visible light driven carbon dioxide, and a preparation method and application thereof. The catalyst is formed by compounding the photosensitizer, the semiconductor carrier and the metal polymalocyanine catalytic center, and can realize high-efficiency and high-selectivity photocatalytic carbon dioxide conversion. Background With the continued consumption of fossil fuels and the continual rise in global carbon emissions, greenhouse effect and climate change have become serious challenges for humans. The method has the advantages that the carbon dioxide (CO 2) is converted into chemicals or fuels with high added value by utilizing solar energy, so that the recycling of greenhouse gases can be realized, the solar energy can be stored in a chemical energy form, and a very promising solution is provided for constructing a sustainable energy circulation system. In the technical field, the design and development of semiconductor photocatalysts are key cores. Titanium dioxide (TiO 2) is widely used as a basic photocatalytic material because of the advantages of high chemical stability, no toxicity, low cost and the like. However, tiO 2 has a broad forbidden band, mainly absorbs ultraviolet light with a wavelength less than 400 nm, and has weak response to visible light dominant in the solar spectrum, resulting in fundamental limitation of solar energy conversion efficiency. In order to improve the visible light response capability of TiO 2, researchers generally adopt a dye sensitization strategy, and the spectrum absorption range of the dye sensitization strategy is expanded by loading a photosensitizer with strong visible light absorption capability. Among them, ruthenium terpyridyl complex is one of the most commonly used photosensitizers due to its wide visible light absorption band, long excited state lifetime and good redox stability. Although this strategy can improve the response capability of the system under visible light to some extent, pure dye sensitized TiO 2 still faces the following inherent limitations: 1. the photo-generated charge separation efficiency is insufficient, namely, in the process of injecting electrons into a semiconductor conduction band by an excited state photosensitizer, electron-hole pairs are easy to be combined, so that the light quantum efficiency is low; 2. The lack of efficient catalytic sites, namely the surface of TiO 2 is not an efficient active center for CO 2 reduction, and the adsorption and activation capability of CO 2 are limited, so that the reaction kinetics is slow and the product selectivity is difficult to control; Based on the background technology, the invention aims to solve the following problems in the existing photocatalytic CO 2 reduction technology: 1. The problem of low utilization rate of visible light by the wide band gap semiconductor TiO 2 Current photocatalytic technology relies primarily on wide bandgap semiconductor materials, typified by TiO 2. However, the forbidden bandwidth of TiO 2 is typically over 3.0 eV, and its light absorption range is mainly limited to the ultraviolet region (wavelength <400 nm), while ultraviolet light only accounts for about 4-5% of the total energy of the solar spectrum. This means that under natural lighting conditions, more than 90% of the solar radiation energy is not effectively utilized, resulting in a lower level of solar energy conversion efficiency of the photocatalytic system. This severely limits the feasibility and efficiency of existing TiO 2 -based photocatalysts in practical solar drive applications. 2. The single dye sensitization system has the problems of low charge separation efficiency and insufficient catalytic active sites To extend the spectral response range of TiO 2, dye sensitization technology has become the dominant solution. Although this strategy can effectively enhance the visible light absorption capacity, dye sensitization systems still face two key limitations, namely the problem of recombination of photogenerated electron-hole pairs. In the process of injecting electrons into a semiconductor conduction band in a dye excited state, part of electrons and holes are recombined, so that the charge separation efficiency is reduced, and the surface of TiO 2 lacks a catalytic active site special for CO 2 reduction. Although the surface of the semiconductor has certain catalytic activity, the lack of specific adsorption sites and activation centers for CO 2 molecules leads to slow reaction kinetics and poor product selectivity, and the efficient CO 2 conversion is difficult to realize. 3. The selectivity of heterogeneous photocatalytic system to CO 2 reduction products is to be improved In the photocatalytic C