Preparation method of microgrid structure a photocatalyst

Abstract

The invention provides a method for preparing photocatalyst with microgrid construction which is to combine an N type semiconductor with a P type semiconductor or combine metal with a semiconductor. The concrete procedure is as follows: an underlay layer is firstly prepared with a layer of N type or P type semiconductor film, and then the surface of the film is prepared with a layer of middle moulding board layer, finally, a layer of P type or N type semiconductor or metal is deposited on the uppermost layer; after the moulding board layer is eliminated, the underlay semiconductor film is compounded with the uppermost semiconductor or metal microgrid to obtain P-N hetero junction photocatalyst and semiconductor photocatalyst with decorated surface of metal microgrid. The invention solves the problem of uneven combination in the prior surface modification method, the grid structure with regular structure ensures that the surfaces of the two materials are orderly separated, which increases the contact area with organic matter, accelerates the process of transporting photo-induced carrier, lowers the combination probability of electron hole and raises the quantum efficiency of photocatalysis.

Description

technical field [0001] The invention relates to a novel modification method of a semiconductor photocatalyst, in particular to a preparation method of a microgrid structure photocatalyst. Background technique [0002] Mainly wide bandgap semiconductors (TiO 2 The first-generation photocatalysts of ZnO or ZnO use ultraviolet light, which has the defect that they can hardly utilize visible light. Countries all over the world are competing to develop the second-generation photocatalysts that can not only efficiently utilize ultraviolet light, but also utilize visible light. At present, there are still several key scientific and technical problems in the first generation of photocatalytic technology, which greatly restricts its wide industrial application. Wherein the most prominent problem is: (1) quantum efficiency is low (~4%), it is difficult to handle a large amount of and high concentration waste water and waste gas; (2) solar energy utilization rate is low. Due to the e...

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Problems solved by technology

Wherein the most prominent problem is: (1) quantum efficiency is low (~4%), it is difficult to handle a large amount of and high concentration waste water and waste gas; (2) solar energy utilization rate is low

If TiO 2 —Cu 2 O semiconductor photocatalyst compound is not uniform or the content is too high, which will lead to the obstruction of the photogenerated carrier transport process, and the accumulated electrons are easily absorbed by Cu. 2 captured by O, leading to the occurrence of composite photocatalyst poisoning

[0009] When illuminated, electron-hole pairs are generated in the semiconductor body. After these carriers diffuse to the surface, they have a catalytic effect. These carriers reach the surface in the form of diffusion, and the movement path is random, and the movement path is long. The previous recombination probability was high, but the current p-n heterojunction new photocatalyst is recombined in the form of doping and multilayer film, although the heterojunction composed of two semiconductors with matching energy bands is helpful for photogenerated electron holes Right separation, but in the process of carrier diffusion from the bottom material to the upper surface, the probability of recombination between the carriers of the two materials in the body is high, and the separated carriers cannot diffuse to the upper surface and cannot be absorbed by organic matter Utilization, the photocatalytic efficiency is low, the composite material can only shorten the diffusion distance of the carrier to the surface, and effectively improve the photocatalytic quantum efficiency

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