3D Porous Pyramid Heterostructure Array Realizing Efficient Photo-Electrochemical Performance

Direct photo-electrochemical (PEC) water splitting is of great practical interest for developing a sustainable energy systems, but remains a big challenge owing to sluggish charge separation, low efficiency, and poor stability. Herein, a 3D porous In2O3/In2S3 pyramid heterostructure array on a fluorine-doped tin oxide substrate is fabricated by an ion exchange-induced synthesis strategy. Based on the synergistic structural and electronic modulations from density functional theory calculations and experimental observations, 3D porous In2O3/In2S3 photoanode by the protective layer delivers a low onset potential of approximate to 0.02 V versus reversible hydrogen electrode (RHE), the highest photocurrent density of 8.2 mA cm(-2) at 1.23 V versus RHE among all the In2S3 photoanodes reported to date, an incident photon-to-current efficiency of 76% at 400 nm, and high stability over 20 h for PEC water splitting are reported. This work provides an alternative promising prototype for the design and construction of novel heterostructures in robust PEC water splitting applications.