Nanoengineered Kesterite Photocathodes: Enhancing Photoelectrochemical Performance for Water Splitting and Beyond.

Harnessing solar energy for the production of storable and transportable chemicals via photoelectrochemical (PEC) reactions offers a promising solution to overcome the intermittence of solar irradiation. Kesterites have been known as cost-efficient, environmentally friendly, and efficient semiconductor photoelectrode materials for PEC solar fuel production. While significant progress has been made in water splitting, there is increasing attention paid to extending applications to CO reduction, ammonia synthesis, and more. However, when efficient kesterite-based photoelectrodes are designed for water splitting and beyond, it is crucial to comprehensively consider both photoelectrode activity and reaction selectivity. This review elaborates on strategies for rationally designing kesterite-based photoelectrodes by optimizing photoactivity in terms of photogenerated charge migration and regulating the surface catalytic sites through nanoscale engineering. More importantly, it discusses optical management and system integration to advance PEC device design for future scalable applications. The perspectives and challenges are also proposed for future solar fuel applications.