Simultaneous Modulation of Interface Reinforcement, Crystallization, Anti-Reflection, and Carrier Transport in Sb...

In this study, an effective quadruple optimization integrated synergistic strategy is designed to fabricate quality Sb gradient-doped SnO₂ /Sb₂ S₃ heterostructure for an efficient photoelectrochemical (PEC) cell. The experimental results and theoretical calculations reveal that i) optical absorption matching is realized by combining the anti-reflection of SnO₂ and high light absorption ability of Sb₂ S₃ in the visible region; ii) interface reinforcement is carried out by coordinating gradient-distributed Sb in SnO₂ with S in S-rich precursor of Sb₂ S₃ for improving the Sb₂ S₃ crystallization process and matching crystalline lattice of Sb:SnO₂ and Sb₂ S₃ ; iii) ultrahigh electron mobility is achieved by making Sb gradient-doped SnO₂ ; iv) carrier separation and transport are accelerated by constructing type-II heterojunction with appropriate energy level alignment and forming a high-speed electron transport channel. All of above-mentioned optimization effects are integrated into a synergistic strategy for constructing the Sb:SnO₂ /Sb₂ S₃ photoanode, achieving a photocurrent density of 2.30 mA cm^-2 , hydrogen generation rate of 30.03 µmol cm^-2 h^-1 , and decent working stability. Notably, this method can also be used in other large-scale fabrication processes, such as drop-casting, spray-coating, blade-coating, printing, slot-die, etc. Moreover, this universal integrated strategy paves an avenue to fabricate efficient photoelectrodes with excellent photoelectrochemical performances.