Photocatalytic reduction of CO2 with H2O vapor into solar fuels over Ni modified porous In2O3 nanosheets

In this work, Ni modified porous In2O3 photocatalysts were synthesized by a facile precipitation approach and used for photocatalytic reduction of CO2 into renewable fuels. A series of characterization techniques including XRD, SEM, TEM/HRTEM, PL spectrum, UV-vis DRS, and CV were performed to investigate the crystal structure, morphology, optical and electronic property of catalysts. The results showed that doping of Ni in the lattice of In2O3 obviously decreased the crystal size, narrowed band gap and improved visible light absorption capability. Meanwhile, the strength and amount of adsorbed CO2 species were greatly enhanced after the doping of Ni due to the increase of active sites. As a result, Ni doped In2O3 samples show much higher photocatalytic activity for CO2 reduction compared to undoped one. With optimal Ni doping amount, the highest production rates of H-2, CO and CH4 were 27.8, 20.8 and 66.2 mu mol.g(cat)(-1).h(-1), respectively, which was about 4.9, 2.7 and 3.1 times higher than undoped In2O3, respectively. This work provides insights on designing and synthesizing highly active photocatalysts for solar fuel production.