Quantum Dots-Based Photoelectrochemical Hydrogen Evolution from Water Splitting

Solar-driven photoelectrochemical (PEC) hydrogen evolution is a promising and sustainable approach to convert solar energy into a fuel that can be stored. Semiconductor quantum dots (QDs) are increasingly used in PEC devices due to their broad composition/size/shape tunable absorption spectrum (from ultraviolet to near-infrared, with significant overlap with the solar spectrum). Despite significant efforts and recent progress, several major challenges remain unresolved in this fast-developing field. Here, the latest progress in tailoring the materials, structure, and performance of QDs-based PEC H-2 generation, including photoanodes, photocathodes, and tandem PEC systems, is summarized. In particular, recent strategies developed for PEC H-2 generation are critically analyzed. Specific features of QDs (e.g., size/shape/composition-tunable absorption band edge arising from quantum confinement, ease of fabrication through chemical approaches, and multiple exciton generation), charge generation, and charge transfer of photoelectrodes and their implications on the performance of PEC devices are discussed. Future challenges and opportunities working, toward high-efficiency and stable QDs-based PEC applications are discussed in the conclusion.