In Situ Reconstruction of a Highly Integrated Cu/Cu₂O/MoO₂ Dual Heterojunctions for High-Performance CO₂ Photothermal Catalysis.

Abstract

During heterogeneous photothermal catalysis, catalysts are prone to undergo random and disordered structural evolution, which poses a severe challenge to the construction of advanced photothermal catalytic systems integrating photoexcited charge carrier separation, molecular activation, and active-site engineering. In this work, we employ an in situ reconstruction strategy to fabricate a highly integrated Cu/Cu₂O/MoO₂ composite catalyst using Cu₃Mo₂O₉ as the precursor under a CO₂/H₂ reaction atmosphere. The as-constructed Cu/Cu₂O Schottky junction and Cu₂O/MoO₂ p-n junction form a dual-heterojunction structure, enabling efficient separation of photogenerated charge carriers. Meanwhile, amorphous MoO₂ with abundant oxygen vacancies and Cu/Cu₂O provide functionally complementary activation sites for CO₂ activation and H₂ dissociation/spillover, respectively. Benefiting from the efficient synergistic interplay among the three components (Cu, Cu₂O, and MoO₂), the Cu/Cu₂O/MoO₂ catalyst enables the efficient conversion of CO₂ via the photothermal reverse water-gas shift (RWGS) reaction, delivering a superior CO production rate of 14.65 mmol g^-1 h^-1 alongside ultra-long stability, retaining high activity across an impressive 215-h continuous reaction run. This study offers a new avenue for the construction of integrated functional photothermal catalysts with high performance via an in situ reconstruction approach.