PREPARATION METHOD AND USE OF THICKNESS-CONTROLLABLE BISMUTH NANOSHEET AND BISMUTH ALLOY NANOSHEET

摘要

The present disclosure relates to a preparation method and use of a thickness-controllable bismuth nanosheet and its alloy, in order to solve the technical problems that the existing metal catalysts for the conversion of carbon dioxide to formic acid exhibit a low efficiency, a high overpotential, a relatively positive hydrogen evolution potential, and a poor stability. The present disclosure for the first time obtains a bismuth nanosheet of a single atom layer thickness with a thickness of only 0.7 nm through an aqueous solution reduction method by using a bismuth salt compound as a raw material, using ethylene glycol ethyl ether as a solvent, and using a highly reductive aqueous solution containing NaBH₄, LiBH₄ or the like as a reducing agent, under a protection atmosphere of an inert gas; and the thickness is adjustable. The bismuth nanosheet prepared according to the present disclosure exhibits an excellent CO₂ catalytic reduction property. In the case of a 330 mV overpotential, the Faradic efficiency of catalyzing CO₂ to produce formic acid can reach 98%, the initial overpotential is as low as 80 mV, and the stability lasts for as long as 75 h. Moreover, even if treated at a temperature of 300° C. for 4 h, the thickness and catalytic property of the bismuth nanosheet are almost unchanged, further demonstrating its ultrahigh stability.