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

The quest for sustainable photocatalytic CO₂ 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 C₂H₄ and C₂H₆ 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 CO₂ concentrations at the catalyst interface, fostering conditions conducive to promoting C─C coupling reactions for the generation of C2 products.