Hole-Transfer-Layer Modification of Quantum Dot-Sensitized Photocathodes for Dramatically Enhanced Hydrogen Evolution

Photoelectrochemical (PEC) water splitting involving a sensitized photocathode has emerged as an extremely promising pathway for achieving solar-to-fuel conversion. Here it is reported that merely by modulating the morphology of hole-transfer layer of NiO film to give a regular porous structure, the PEC performance of quantum dots (QDs) sensitized photocathodes can be dramatically enhanced. Mechanistic insights reveal that the porous structure not only increases the loading amount of QDs for enhanced light capture, but also facilitates the process of interfacial hole transfer and migration, which enable a 2.6-fold enhancement of PEC performance to a photocurrent of approximate to 136 A cm(-2). The strategy introduced here provides an effective and facile pathway for further improving the efficiency of artificial photosynthesis.