Transition metal (Ni, Cu)-doped In2O3-based photocatalysts for enhanced visible light photocatalytic carbon dioxide reduction

Converting carbon dioxide into fuel via photocatalysis holds immense significance in advancing the cause of sustainable energy generation. In this work, co-doped In 2 O 3 nanosheets with two transition metals, nickel (Ni) and copper (Cu), were successfully prepared using a straightforward ammonia precipitation and calcination technique. Notably, the 10 %Ni-5 %Cu-In 2 O 3 sample exhibited a remarkable CO generation rate of 528.8 μmol g −1 h −1 , which is a substantial 43.63-fold increase compared to the pristine In 2 O 3 (12.1 μmol g −1 h −1 ). Furthermore, the selectivity of the CO product was significantly enhanced from 19.7 % to 69.4 %, marking a significant improvement. The incorporation of Ni and Cu effectively modulated the energy band positions of In 2 O 3 , the synergistic modulation of these bimetals jointly augmented the light absorption of In 2 O 3 across various visible wavelength regions. Additionally, the introduction of Ni and Cu notably prolonged the lifetime of photogenerated carriers and facilitated the spatial separation of electrons and holes. The smaller radius of the doped Ni and Cu ions compared to In may have induced defect formation, leading to a stronger adsorption capacity. Our findings not only underscore the efficacy of transition metal co-doping in photocatalytic CO 2 reduction but also offer valuable insights into the design and fabrication of such catalysts.