Lead-free double perovskite Cs2AgBiBr6/RGO composite for efficient visible light photocatalytic H2 evolution

Lead halide perovskites have demonstrated great potential in photovoltaic and photocatalytic applications. Despite of their high efficiency, the lead toxicity issue could limit their applications in photocatalysis. Herein, lead-free double perovskite Cs2AgBiBr6 (CABB) combined with reduced graphene oxide (RGO) was facilely synthesized (donated as CABB/RGO) and applied for H2 evolution in saturated HBr aqueous solution. The CABB/RGO composite with optimal RGO loadings exhibited enhanced photocatalytic activity than bare CABB particles, which could be ascribled to the facilitated charge separation and transfer by RGO. As high as 489 μmol g−1 H2 can be produced within 10 h under visible light irradiation (λ ≥ 420 nm, 300 W Xe lamp) using CABB/RGO as photocatalyst. Furthermore, the champion photocatalyst of CABB/2.5%RGO showed high stability for 120 h continuous photocatalytic H2 evolution. This study suggests Cs2AgBiBr6-based perovskite are promising candidate for photocatalytic hydrogen generation.