Efficient infrared-light-driven photothermal CO2 reduction over MOF-derived defective Ni/TiO2

Infrared (IR) light serves as an attractive renewable source of solar energy for photothermal CO2 methanation. Herein, we report the synthesis of Ni nanoparticles (NPs) supported on TiO2 (Ni/TiO2) derived from MIL-125(Ti) (MOFs), which achieves a CH4 production rate of 271.9 mmol gNi-1 h-1 with nearly 100% selectivity and good durability at least 48 h under IR irradiation. The results indicate the catalytic performance is predominantly driven by thermal energy from efficient IR light conversion. IR light acts as the most effective light source and induces highest activity and CH4 selectivity over 8Ni/TiO2 compared with UV–vis and full spectrum light. Highly-dispersed small-size Ni NPs, rich oxygen vacancies (OVs), strong adsorption capacity and enhanced CO2 activation ability contribute to the high catalytic performance. OVs over Ni/TiO2 play a crucial role in the CH4 formation. This work demonstrates a feasible strategy towards the synthesis of MOF-derived catalysts for efficient photothermal CO2 methanation.