Surface-modified heterogeneous knot titanium dioxide photonic crystal catalyst and preparation thereof

Abstract

The invention discloses a surface-modified heterogeneous knot titanium dioxide photonic crystal thin film catalyst. The catalyst is of a three-dimensional ordered inverse opal structure and has an anatase/rutile heterogeneous knot crystal structure, and a photonic band gap is located at a visible light absorption region of the catalyst. The invention further discloses a preparation method of the surface-modified heterogeneous knot titanium dioxide photonic crystal thin film catalyst. The preparation method comprises the following steps: preparing TiO2 sol by virtue of an in-situ modification method; preparing polystyrene microsphere colloidal crystal template by virtue of a vertical deposition method; preparing a nano-TiO2 photonic crystal with the three-dimensional ordered inverse opal structure by virtue of a dipping-vertical pulling method; and carrying out high-temperature calcination, so as to obtain the surface-modified heterogeneous knot titanium dioxide photonic crystal thin film catalyst. The catalyst has very strong visible-light responsivity, and the visible light chemical reaction is enhanced by virtue of a slow photon effect of the photonic crystal; by utilizing the heterogeneous knot structure, the separation of photon-generated current carriers is promoted, and the visible light catalysis capacity is improved; and furthermore, equipment is simple and easy to operate.

Description

technical field [0001] The invention relates to the technical field of catalysis, in particular to a surface-modified heterojunction titanium dioxide photonic crystal thin film catalyst and a preparation method thereof. Background technique [0002] In the 21st century, resource scarcity, energy shortage and environmental pollution are becoming more and more serious. These have become the main problems and challenges facing the world today. In order to achieve sustainable development and the harmonious unity of the ecological environment, human survival and social development, human beings must be required to take active measures to address these problems and challenges, which makes pollution prevention and control a global issue. In recent decades, research on photochemical degradation of pollutants has been continuously emerging and in-depth. Among them, semiconductor photocatalysis has attracted people's attention due to its incomparable biodegradation speed, non-selectiv...

AI Technical Summary

Problems solved by technology

Such as metal, non-metal element doping, etc. These doping forms reduce the semiconductor band gap and expand the photoresponse range to a certain extent, but whether it is gap doping or replacement doping, it is often found in TiO 2 The electron-hole recombination probability is increased in the crystal, which leads to the enhancement of the visible light catalytic ability of the catalyst, while the ultraviolet photocatalytic ability decreases

[0004] Another problem is that the TiO 2 Most of the photocatalysts based on the powder particle type, and the powder type TiO 2 Photocatalysts have practical problems such as difficulty in recycling and secondary pollution in environmental purification, which directly restrict their large-scale practical application.

However, TiO 2 The nanoparticle thin film catalyst is composed of a large number of nanoparticle agglomerations, which are highly dense, and the photocatalytic reaction is an interface reaction. Whether it is a liquid phase reaction or a gas phase reaction system, in the photocatalytic reaction process, only the outermost layer of TiO 2 Contact with target degradation products, resulting in small contact area, few surface active sites, and low photocatalytic efficiency

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