Photocatalytic reduction of CO 2 with H 2 O vapor into solar fuels over Ni modified porous In 2 O 3 nanosheets

In this work, Ni modified porous In 2 O 3 photocatalysts were synthesized by a facile precipitation approach and used for photocatalytic reduction of CO 2 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 In 2 O 3 obviously decreased the crystal size, narrowed band gap and improved visible light absorption capability. Meanwhile, the strength and amount of adsorbed CO 2 species were greatly enhanced after the doping of Ni due to the increase of active sites. As a result, Ni doped In 2 O 3 samples show much higher photocatalytic activity for CO 2 reduction compared to undoped one. With optimal Ni doping amount, the highest production rates of H 2, CO and CH 4 were 27.8, 20.8 and 66.2 μmol∙gcat-1∙h-1, respectively, which was about 4.9, 2.7 and 3.1 times higher than undoped In 2 O 3, respectively. This work provides insights on designing and synthesizing highly active photocatalysts for solar fuel production.