Complete Photocatalytic Reduction of CO₂ to Methane by H₂ under Solar Light Irradiation

Nickel supported on silica–alumina is an efficient and reusable photocatalyst for the reduction of CO₂ to methane by H₂, reaching selectivity above 95% at CO₂ conversion over 90%. Although NiO behaves similarly, it undergoes a gradual deactivation upon reuse. About 26% of the photocatalytic activity of Ni/silica–alumina under solar light derives from the visible light photoresponse.