Novel step-scheme (S-scheme) heterojunction photocatalysts toward artificial photosynthesis

The conversion of sunlight energy into fuel through photocatalytic CO2 photoreduction, called artificial photosynthesis, is a promising idea to simultaneously mitigate the greenhouse effect and energy crises. Although many studies have been undertaken, challenges remain and require further improvements. Hence, current and future studies for CO2 photoreduction are developing and tailoring novel photocatalysts that could offer potential activity, attractive selectivity, good stability, and reasonable cost. Among potential candidates, exploration of various heterojunction photocatalysts to boost CO2 photoreduction is of great importance. Notably, S-scheme photocatalysts could be further enhanced by proper adjustment of photocatalysts (oxidation photocatalyst and reduction photocatalyst) through doping, coupling with 2D nanomaterials, heterojunction formation, and amendment with cocatalysts to improve charge separation. In the present study, we have briefly discussed and summarized Step-scheme (S-scheme) heterojunction photocatalysts for CO2 reduction.