A novel amorphous alloy photocatalyst (NiB/In2O3) composite for sunlight-induced CO2 hydrogenation to HCOOH

Photocatalytic CO 2 hydrogenation into fuels and value-added chemicals is considered as a promising strategy for CO 2 conversion and utilization. However, the photocatalysts used usually displays low efficiency and poor durability. Herein we developed a novel catalyst by combining NiB amorphous alloy with In 2 O 3 semiconductor, which exhibited very high HCOOH yield (5158.0 umol g −1 h −1 ) in CO 2 hydrogenation under sunlight irradiation. The In 2 O 3 acted as a photocatalyst for generating photoelectrons to reduce CO 2 and provided sufficient surface hydroxyl (In−OH) groups favouring CO 2 adsorption during the reaction. The high dispersion of NiB nanoparticles (co-catalyst) and interaction with In 2 O 3 provided the rich interface between NiB and In 2 O 3 , favoring the surface reactions between CO 2 and H 2 . Meanwhile, the unique amorphous alloy structure made the Ni electron-enriched, which promoted CO 2 hydrogenation through the H 2 dissociation. More importantly, the NiB amorphous alloy with good electric conductivity facilitated the transfer of photoelectrons from In 2 O 3 , which sufficiently diminished the photoelectron-hole recombination, leading to the enhanced quantum efficiency in photocatalytic CO 2 hydrogenation.