Z-scheme (BiO)2CO3|Cu2O photocatalyst for highly selective CO2 to CO conversion

Abstract

Photocatalytic conversion presents a promising approach for developing eco-friendly CO2 reduction catalysts; however, achieving high reaction efficiency and product selectivity remains challenging. In this study, an exceptionally efficient photocatalyst for CO2 conversion was developed by constructing a Z-scheme heterojunction through the growth of p-type Cu2O crystals within an n-type (BiO)2CO3 layer. This architecture effectively suppressed charge recombination, markedly enhancing photoconversion efficiency. While single Cu2O semiconductors exhibit selective CO2-to-CO reduction, their catalytic efficiency is low (CO production of 0.24 μmol g-1h-1). In contrast, the Z-scheme system with (BiO)2CO3 significantly improved charge separation and transfer efficiency. This heterojunction demonstrated outstanding catalyst activity in CO2 conversion, achieving 100 % selectivity and producing 9.79 μmol g-1h−1 of CO gas, while also maintaining high stability through repeated cycles of photocatalytic use. © 2024 Elsevier B.V.