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

Photocatalytic CO2 hydrogenation into fuels and value-added chemicals is considered as a promising strategy for CO2 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 In2O3 semiconductor, which exhibited very high HCOOH yield (5158.0 umol g-1 h-1) in CO2 hydrogenation under sunlight irradiation. The In2O3 acted as a photocatalyst for generating photoelectrons to reduce CO2 and provided sufficient surface hydroxyl (In-OH) groups favouring CO2 adsorption during the reaction. The high dispersion of NiB nanoparticles (co-catalyst) and interaction with In2O3 provided the rich interface between NiB and In2O3, favoring the surface reactions between CO2 and H2. Meanwhile, the unique amorphous alloy structure made the Ni electronenriched, which promoted CO2 hydrogenation through the H2 dissociation. More importantly, the NiB amorphous alloy with good electric conductivity facilitated the transfer of photoelectrons from In2O3, which sufficiently diminished the photoelectron-hole recombination, leading to the enhanced quantum efficiency in photocatalytic CO2 hydrogenation.

Automated summary

A novel catalyst was developed by combining NiB amorphous alloy with In2O3 semiconductor, achieving high efficiency in CO2 hydrogenation under sunlight irradiation. This catalyst enhanced the quantum efficiency of photocatalytic CO2 hydrogenation by providing rich interfaces, promoting surface reactions, and facilitating CO2 hydrogenation through various mechanisms.