A kind of preparation method of silicon-based catalyst for photoelectrochemical reduction of nitrogen

Abstract

The invention discloses a method for preparing a silicon-based catalyst for photoelectrochemical reduction of nitrogen. The steps are: (1) washing the silicon chip with acetone, ethanol and water in sequence, and then putting it into a piranha solution and a hydrofluoric acid solution for reaction ; (2) Then put the silicon chip into the mixed solution of hydrofluoric acid and silver nitrate and the mixed solution of hydrofluoric acid and hydrogen peroxide in turn; (3) Put the reacted silicon chip into the solution of nitric acid and hydrofluoric acid in turn reaction; (4) laminating a titanium dioxide layer on the surface of the silicon chip; (5) placing the silicon chip in an aqueous solution of bismuth nitrate, washing it after electrochemical reduction, and drying in vacuum to obtain the silicon-based catalyst. The invention prepares a silicon nanowire array coated with a titanium dioxide layer as a light-absorbing center, and bismuth nanoparticles as a catalyst for an electrochemical catalytic center, so that the catalyst has both a good semiconductor light-absorbing center and an excellent electrochemical active center, and is used for photoelectric catalysis of nitrogen It has high catalytic efficiency in reduction reaction.

Description

technical field [0001] The invention relates to the technical field of catalyst preparation, in particular to a method for preparing a silicon-based catalyst for photoelectrochemical reduction of nitrogen. Background technique [0002] Ammonia has played a vital role in the development of human society. It can be used as a fertilizer to promote the production of food in the world, and it also shines in medicine and energy. Under the background of the world energy crisis and the increasingly severe greenhouse effect, it is imperative to develop an efficient, clean and sustainable ammonia synthesis process. The use of nitrogen and water as reactants to synthesize ammonia has received extensive attention and research because of its readily available raw materials. The chemical methods for using nitrogen to synthesize ammonia in the prior art mainly include photocatalytic nitrogen reduction and electrocatalytic nitrogen reduction. [0003] Photocatalytic nitrogen reduction can ...

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Problems solved by technology

[0007] The present invention aims to overcome the problem that photogenerated holes of semiconductor catalysts in the photocatalytic nitrogen reduction in the prior art are easy to recombine with electrons, the catalyst in the electrocatalytic nitrogen reduction cannot effectively inhibit the hydrogen evolution reaction, and there is no high-efficiency catalyst that can be used in the photocatalytic nitrogen reduction reaction in aqueous solution To solve this problem, provide a method for preparing a silicon-based catalyst for photoelectrochemical reduction of nitrogen, prepare a catalyst with a silicon nanowire array coated with a titanium dioxide layer as the light-absorbing center, and bismuth nanoparticles as the electrochemical catalytic center, so that the catalyst has both Good semiconductor light-absorbing centers also have excellent electrochemical active centers, which have high catalytic efficiency when used in photoelectrocatalytic nitrogen reduction reactions

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