Recent advances in heterogeneous catalysis of solar-driven carbon dioxide conversion.

Solar-driven carbon dioxide (CO2) conversion including photocatalytic (PC), photoelectrochemical (PEC), photovoltaic plus electrochemical (PV/EC) systems, offers a renewable and scalable way to produce fuels and high-value chemicals for environment and energy sustainability. This review summarizes the basic fundament and the recent advances in the field of solar-driven CO2 conversion. Expanding the visible-light absorption is an important strategy to improve solar energy conversion efficiency. The separation and migration of photogenerated charges carriers to surface sites and the surface catalytic processes also determine the photocatalytic performance. Surface engineering including co-catalyst loading, defect engineering, morphology control, surface modification, surface phase junction, and Z-scheme photocatalytic system construction, have become fundamental strategies to obtain high-efficiency photocatalysts. Similar to photocatalysis, these strategies have been applied to improve the conversion efficiency and Faradaic efficiency of typical PEC systems. In PV/EC systems, the electrode surface structure and morphology, electrolyte effects, and mass transport conditions affect the activity and selectivity of electrochemical CO2 reduction. Finally, the challenges and prospects are addressed for the development of solar-driven CO2 conversion system with high energy conversion efficiency, high product selectivity and stability.

Rich oxygen vacancies in confined heterostructured TiO2@In2S3 hybrid for boosting solar-driven CO2 reduction.

Solar energy driving CO2 reduction is a potential strategy that not only mitigates the greenhouse effect caused by high CO2 level in atmosphere, but also yields carbon chemicals/fuels at the same time. Herein, a facile way to design the heterogeneous TiO2@In2S3 hollow structures possessing robust light harvesting in both ultraviolet and visible regions is proposed and exhibits a higher generation rate of 25.35 and 1.24 µmol·g-1·h-1 for photocatalytic CO2 reduction to CO and CH4, respectively. The excellent photocatalytic catalytic performance comes from i) the confined heterostructured TiO2@In2S3 possesses a suitable band structure and a broadband-light absorbing capacity for CO2 photoreduction, ii) the rich interfaces between nanosized TiO2 and In2S3 on the shell can significantly reduce the diffusion length of carriers and enhance the utilization efficiency of photogenerated electron-hole pairs, and iii) enriched surface oxygen vacancies can provide more active sites for CO2 adsorption.