Photoelectrodes of Cu2O with interfacial structure of topological insulator Bi2Se3 contributes to selective photoelectrocatalytic reduction of CO2 towards methanol

Abstract

Artificial photosynthesis emerges as feasible solution to diminish CO2 content in the atmosphere. Photoelectrocatalysis can diminish CO2 concentration while generating useful resources such as methanol. Here an alternative multilayer photoelectrode of FTO/Cu/Bi2Se3-Se/Cu2O is developed to enhance selective reduction of CO2 towards methanol. A novel electrosynthetic approach is described as strategy to modulate the atomic composition of p-type bismuth selenide chalcogenide intralayer. This method enhanced performance and selectivity of n-type Cu2O photoelectrocatalysts. Alkaline pH conditions favored yield and selectivity towards methanol production from CO2. The formation of an n-p heterojunction affects the Cu2O performance on CO2 reduction. The novel engineered FTO/Cu/Bi2Se3-Se/Cu2O multilayer photoelectrodes allowed obtaining up to 4.5 mM of methanol, which correspond to 3-fold higher concentration than conventional FTO/Cu2O electrodes reported in literature. Photoelectrodes of FTO/Cu/Bi2Se3-Se/Cu2O overperform conventional Cu2O in terms of kinetics and selectivity towards methanol production.