Loading metal nanoparticles on the CoAl-LDH/CGCNN S-scheme heterojunction for efficient photocatalytic CO2 reduction under visible light

Abstract

Converting CO2 into high-value products by photocatalysis can alleviate the global greenhouse effect and energy crisis. In this work, CoAl-LDH/CGCNN-Metal NPs (AC-M) ternary photocatalysts were synthesized by calcination, hydrothermal, and ultrasonic self-assembly methods. In pure water, the best sample AC-Au could convert CO2 into CO, CH4, C2H4, and C2H6 with the yields of 5.93, 17.68, 1.25 and 2.15 µmol g−1h−1, respectively, and exhibited good stability within 5 cycles (30 h). The synergistic effect between S-scheme heterojunction and metal NPs could broaden the composite's photo-response range and promote the separation of photogenerated carriers. Furthermore, the metal NPs could also serve as the electron-rich centers to improve the chemisorption of CO2 and convert it into C1 and C2 products under visible light. This work can provide meaningful guidance for studying the efficient reduction of CO2 to C1 and C2 products by S-scheme heterojunction/metal NPs ternary photocatalytic system.