On the CO2 photocatalytic reduction over indium tin oxide (ITO) ultra-thin films in water vapor: Experimental and theoretical study

Abstract

Artificial photosynthesis that converts CO2 and H2O into compounds with added value is a viable method for reducing atmospheric CO2 concentration. In this study, we investigated the photocatalytic activity of ultrathin indium tin oxide (ITO) films on rigid and flexible substrates for CO2 reduction in water vapor and batch and flow setups. To explain a viable reaction mechanism for the 2760 ± 10 % μmol.gcat-1.hr-1 production rate achieved in a continuous reaction system, several theoretical models were developed. According to DFT simulation results, oxygen vacancy might be regarded as the main reaction site for CO2 to CO conversion. Moreover, a viable reaction pathway leading to CH4 formation is proposed. The catalyst’s lower rate of CO2 reduction in the batch reactor as compared with the flow reactor was justified via surface affinity simulation. Our findings highlight the significance of the catalyst’s structural design and reaction media configuration for stability and high activity.