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A direct Z-scheme BiOBr/Bi 2 Sn 2 O 7 photocatalyst with abundant of surface OVs (Vo-BiOBr/Bi 2 Sn 2 O 7) has been designed and synthesized which is applied for photocatalytic degradation under visible light irradiation. The as-prepared Vo-BiOBr/Bi 2 Sn 2 O 7 heterojunctions with abundant surface OVs displays outstanding degradation performance and excellent stability. [Display omitted] Promoting charge migration and enhancing redox ability of photogenerated carriers are important for the development of highly efficient semiconductor-based photocatalyst. Here, BiOBr/Bi 2 Sn 2 O 7 heterojunction with oxygen vacancies (OVs) was constructed by homogeneously depositing Bi 2 Sn 2 O 7 nanoparticles on the Vo-BiOBr surface. The experimental results manifested that Vo-BiOBr/Bi 2 Sn 2 O 7 displayed better performance for rhodamine B, ciprofloxacin, and tetracycline degradation than counterparts without OVs. The characterization results proved OVs played the essential role for enhanced performance via improving the separation efficiency of charge carriers, increasing the visible light harvest, and lowering conduction band position. Moreover, mechanism study revealed that an inner electric field was built at the interface, leading to a Z-scheme path of photogenerated electron. This study provided an efficient strategy for designing highly efficient photocatalyst for solving environmental pollution. [ABSTRACT FROM AUTHOR]

Sufficient generation of H 2 O 2 played an essential role in boosting self-sufficient heterogeneous Fenton reaction. Herein, the dual H 2 O 2 production paths were designed to maximize the yield over H 2 O 2 -etched MoS 2 /FeS 2 Z-scheme heterojunction, whose surface was modified with abundant –OH groups and sulfur vacancies (SVs). Mechanism studies revealed that H 2 O 2 was generated via two-step single-electron reduction by electrons on conduction band, where H 2 O 2 production was significantly improved by the internal hole-scavenging effect from –OH groups. Additionally, electrons surrounding SVs served as another sites for H 2 O 2 production via one-step two-electron reduction even in darkness. H 2 O 2 yield in neutral aqueous solution reached 1.5 mM/g/h without external hole scavenger. Tetracycline and rhodamine B were effectively degraded under light or in darkness. The degradation performance was even comparable to the heterogeneous Fenton reaction. This work provides new insights for the design of self-sufficient heterogeneous Fenton system with exceptional degradation performance. [Display omitted] • E-MoS 2 /FeS 2 with abundant -OH groups and SVs is prepared via surface engineering. • H 2 O 2 yield is largely improved by the internal h+-scavenging effect from –OH groups. • e - surrounding SVs serve as another sites for H 2 O 2 production even in darkness. • In-situ H 2 O 2 yield reaches 1.5 mM/g/h, and it is enough for following Fenton reaction. • Pollutant can be degraded within 25 or 60 min under actual sunlight or in darkness. [ABSTRACT FROM AUTHOR]