Facile and scalable synthesis of Cu2O-SnO2 catalyst for the photoelectrochemical CO2 conversion

CO2 conversion into high-value-added products is becoming increasingly attractive to find substitutes for fossil-based ones and tackle the environmental crisis. Herein, a noble, simple, reproducible, and scalable Cu2O-SnO2 photo-electrocatalyst was synthesized and characterized. Coupling cuprous oxide with tin oxide allowed for protecting unstable Cu+1 species from photo-corrosion. Evidence of the SnO2 stabilization role were found via chronoamperometry tests under chopped light and XPS analysis. An optimized catalytic ink was developed to prepare the photocathodes. The CO2 photo-electroreduction tests demonstrated a prevalent production of CO and formate with Faradaic efficiencies of 35.47 % and 19.58 %, respectively, and a good system stability. Sunlight illumination demonstrated to play a major role to hinder H2 evolution and promote ≥C1+ products formation.