Bi₃TiNbO₉/Bi₂S₃ Heterojunction for Efficient Photosynthesis of H₂O₂ in Pure Water

Abstract Heterojunction engineering has been deemed one of the most promising strategies for promoting charge separation and improving solar‐to‐chemicals efficiency. Howbeit, constructing well‐defined nanoheterojunction with superior photocatalytic activity for H 2 O 2 generation and a clear reaction mechanism remains a formidable challenge. Herein, an in situ vulcanization way to synthesize an intriguing 2D/1D Bi 3 TiNbO 9 /Bi 2 S 3 heterojunction by growing Bi 2 S 3 nanorods on Bi 3 TiNbO 9 microsheet is used for the first time, where an S‐scheme charge transfer mechanism is formed that facilitates the spatial separation of charge carriers. Moreover, the in situ grown Bi 2 S 3 on Bi 3 TiNbO 9 can optimize the interfacial electronic structure and the reaction energy barriers. As a result, the H 2 O 2 yield rate for Bi 3 TiNbO 9 /Bi 2 S 3 can reach 810(2) µmol g −1 h −1 without any sacrificial agents and cocatalysts, ≈6.18 and ≈18.0 times of pristine Bi 3 TiNbO 9 and Bi 2 S 3 , respectively. Importantly, the heterojunction unveiled unprecedented stability, remaining ≈95.46(2)% of the initial one after 13 continuous cycles. This work highlights an innovative in situ vulcanization strategy to engineer oxide perovskite/metal sulfide nanocomposite catalysts for artificial photosynthesis of H 2 O 2 , opening new opportunities for achieving highly efficient photocatalyst systems.