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Abstract Photocatalytic CO2 reduction is considered as a promising strategy for CO2 utilization and producing renewable energy, however, it remains challenge in the improvement of photocatalytic performance for wide‐band‐gap photocatalyst with controllable product selectivity. Herein, the sulfur‐doped In(OH)3 (In(OH)xSy‐z) nanocubes are developed for selective photocatalytic reduction of CO2 to CH4 under simulated light irradiation. The CH4 yield of the optimal In(OH)xSy‐1.0 can be enhanced up to 39 times and the CH4 selectivity can be regulated as high as 80.75% compared to that of pristine In(OH)3. The substitution of sulfur atoms for hydroxyl groups in In(OH)3 enhances the visible light absorption capability, and further improves the hydrophilicity behavior, which promotes the H2O dissociation into protons (H*) and accelerates the dynamic proton‐feeding CO2 hydrogenation. In situ DRIFTs and DFT calculation confirm that the non‐metal sulfur sites significantly weaken the over‐potential of the H2O oxidation and prevent the formation of ·OH radicals, enabling the stabilization of *CHO intermediates and thus facilitating CH4 production. This work highlights the promotion effect of the non‐metal doping engineering on wide‐band‐gap photocatalysts for tailoring the product selectivity in photocatalytic CO2 reduction.

Regulating the electron-hole lifetime would increase the surface charge density of photocatalysts and then promote the photocatalytic conversion of CO2 into hydrocarbons. Herein, Pt and graphdiyne (GDY), respectively, as electron and hole transfer bodies were introduced into a multiple Pt/BiOBr-GDY heterojunction, constructing fast channels of electron and hole transfer and then prolonging their lifetime. Under light irradiation, the Pt/BiOBr-GDY nanocomposite changed the product distribution and significantly allowed the selective photocatalytic CO2 conversion to CH4 and C2 hydrocarbons (C2H4 and C2H6), with the total CxHy selectivity of about 97%. The synergistic effect of Pt and GDY facilitated the separation and transfer of photogenerated electrons and holes on BiOBr, increased the surface charge density, and ultimately improved the efficiency of photocatalytic CO2 reduction. At the same time, due to the characteristics of GDY, it can afford more surface-adsorbed active sites for CO2 and intermediates, thus further improving the photocatalytic efficiency and selectivity. Hence, this work provides an insight into the promotion of the selective photoreduction of CO2 to hydrocarbon products by the synergistic effect of the metal, semiconductor, and GDY. [ABSTRACT FROM AUTHOR]