Regulating Product Selectivity in Photothermal CO ₂ Conversion through Ni Loading on Metallic MoO ₂

Photothermal CO2 methanation builds a sustainable and energy-efficient strategy to convert CO2 into value-added fuels under mild conditions. Herein, we report a broadband-responsive Ni/MoO2 catalyst with tunable Ni loading for selective CO2 hydrogenation under light irradiation. By systematically varying the Ni content, product selectivity can be exactly controlled: 0.2%-Ni/MoO2 yields the highest CO production rate (2.67 mmol g–1 h–1), while 16%-Ni/MoO2 reaches a CH4 production rate of 36.45 mmol g–1 h–1 with nearly 100% selectivity. Structural characterization and in situ spectroscopic analyses disclose that low Ni loading favors NiO formation that captures photogenerated holes to enhance H2 dissociation and promotes CO evolution via weak *CO adsorption. In comparison, high Ni loading generates metal Ni0 encapsulated by NiO, which concentrates the photogenerated electrons to activate CO2 and stabilize *CO intermediates, thereby driving hydrogenation toward CH4 with high efficiency. This work clarifies a clear structure–selectivity relationship and highlights active-site engineering as an effective approach to optimize efficiency and selectivity in photothermal CO2 conversion.