Activation of the Carbon Nitride Surface by Silica in a CO‐Evolving Hybrid Photocatalyst

Photocatalytic reduction of CO2 to CO proceeded by visible light (λ>400 nm) using mesoporous graphitic carbon nitride (C3N4) coupled with a RuII–ReI binuclear complex (RuRe) containing a photosensitizer and catalytic units. The selectivity to CO exceeded 90 % during the initial stage. Photocatalytic reactions (including isotope tracer experiments) and electrochemical measurements revealed that the reaction proceeded according to a two‐step photoexcitation of C3N4 and the RuII photosensitizer unit, that is, it followed the Z‐Scheme mechanism. Modification of C3N4 with highly dispersed silica was found to improve the ability of C3N4 to accommodate RuRe, which enhanced the photocatalytic activity for CO production.