In-situ growth of β-Bi2O3 nanosheets on g-C3N4 to construct direct Z-scheme heterojunction with enhanced photocatalytic activities

In order to construct tighter heterostructures, a novel Z-scheme β-Bi2O3/g-C3N4 composite (xBC) was synthesized by in-situ growth method. The crystal phase, morphology, chemical composition, optical and photoelectrochemical properties of the composites were investigated by XRD, FT-IR, SEM, TEM, XPS, UV–vis DRS, EIS, etc. The characterizations verified that β-Bi2O3 nanosheets grew uniformly on the surface of g-C3N4. Meanwhile, the photocatalytic performance of xBC composites were also evaluated by degrading Rhodamine B (RhB) and p-Nitrophenol (PNP) under visible-light irradiation. As a result, 0.5BC exhibited the most superior performance, the removal efficiencies reached 71.6% for PNP in 300min and 94.8% for RhB in 120 min, with a rate constant (0.0233min−1) of 7.1 and 5.8 times than that of g-C3N4 and β-Bi2O3, respectively. Evidences that Z-scheme carries transfer path were strongly confirmed by XPS, PL and reactive species analysis. Herein, we synthesized a novel direct Z-scheme β-Bi2O3/g-C3N4 heterostructure by in-situ growth method. [Display omitted] •An in-situ growth method was proposed to synthesize g-C3N4/β-Bi2O3 heterojunction.•The growth process of β-Bi2O3 on the surface of g-C3N4 was illustrated in detail.•The Z-scheme charge transfer pathway was proved by various characterizations.•The optimum mass ratio of β-Bi2O3 to g-C3N4 was 0.5 for RhB and PNP degradation.