Modification of CdZnS nanoparticles on nanoporous FeVO4 photoanode to improve photoelectrochemical performance

Abstract

Photoelectrochemical (PEC) performance of semiconductor photoanode can be significantly improved by regulating the energy band alignment to promote carrier separation. This study demonstrates the first application of CdZnS (CZS) nanoparticles to modify FeVO4 (FVO) nanostructure phoyoanode for PEC water splitting. The constructed FVO/CZS photoanode exhibits significantly enhanced PEC performance with a zero-bias solar-driven photocurrent density of 1.00 mA/cm2, which is 11 times and 4.5 times that of unmodified FVO and CZS, respectively. The Tests of the optical absorption and electrochemical spectroscopy demonstrate that the modification of CZS nanoparticles not only improves the light harvesting ability of the FVO/CZS heterojunction nanostructures in the wavelength of 300–500 nm but also establishes a type II band alignment between the interface of FVO and CZS that is conducive to the transport and separation of the charge carriers and prolongs charge lifetime. Consequently, synergistic actions of the improved light harvesting capacity, effective charge transport and separation and the prolonged carrier lifespan enable the designed and fabricated FVO/CZS heterojunction photoanode to get substantially augmented PEC water splitting performance. This work supplies an innovative guidance for designing FVO-based photoanodes to improve photoelectric conversion behavior from the perspective of interface engineering.