CuFeO2/CuInS2 Composite Thin Film Photocathode Prepared by Template Method for CO2 Conversion Into Methanol

Abstract

The huge consumption of fossil fuels in industrialization has caused increasingly aggravated greenhouse effect. To address this problem, converting CO2 into liquid solar fuels by photoelectrochemical technology is highly expected. In order to enhance the photoelectrochemical performance of the photocathodes, the composite thin film photocathodes have been constructed by covering CuFeO2 nanoparticles (CFO NPs) on CuInS2 (CIS) thin film surface by the impregnation (I-CFO/CIS) and the template method (T-CFO/CIS). In addition, the p–p heterostructure is formed between CIS and CFO NPs. Furthermore, the adsorption behaviors of intermediates are altered because of the well dispersed and smaller size of CFO NPs on T-CFO/CIS thin films. As a result, enhanced photoelectrocatalytic CO2 reduction is achieved. The yield of methanol on T-CFO/CIS thin film reaches up to 270 μM, which is 3.5 and 11.2 times as high as that on I-CFO/CIS and CIS thin films, respectively. At the applied voltage of −0.65 V vs saturated calomel electrode (SCE), the maximal faradic efficiency of methanol on T-CFO/CIS photocathodes is as high as 87%.