This book introduces readers to the preparation of two-dimensional metal sulfide/oxide for CO2 photoreduction. Based on two-dimensional metal sulfide/oxide materials, this book establishes the structure-to-property relationships of photocatalyst for CO2 photoreduction, and reveals the intrinsic mechanism of the CO2 photoreduction by virtue of the in situ characterization techniques and the density functional theory calculations. It is anticipated that this book will help to identify empirical guidelines for designing and fabricating high-performance catalysts of solar-driven CO2 reduction.