Bismuth‐Metal and Carbon Quantum Dot Co‐Doped NiAl‐LDH Heterojunctions for Promoting the Photothermal Catalytic Reduction of CO2

Abstract The quest for sustainable photocatalytic CO 2 reduction reactions (CRR) emphasizes the development of high‐efficiency, economically viable, and durable photocatalysts. A novel approach involving the synthesis of Bi‐CDs/LDH heterojunctions, incorporating plasma metals and carbon quantum dots via hydrothermal and co‐precipitation methods, yields remarkable results. The optimized BCL‐4 photocatalyst demonstrates exceptional performance, with C 2 H 4 and C 2 H 6 yields of 1.35 and 2.17 µmol g −1 h −1 , respectively, representing substantial enhancements of 11.25 and 14.47 times compared to the LDH monomer. Moreover, the catalyst exhibits a notable selectivity of 36.6% for C2 products. Plasmonic Bi with high conductivity and carbon quantum dots synergistically enhances visible light absorption and generated additional hot electrons. The electron‐trapping ability of carbon quantum dots is pivotal in creating elevated electron and CO 2 concentrations at the catalyst interface, fostering conditions conducive to promoting C─C coupling reactions for the generation of C2 products.