Exfoliated thin Bi₂MoO₆ nanosheets supported on WO₃ electrode for enhanced photoelectrochemical water splitting

Highlights: • Thin Bi₂MoO₆ nanosheets were prepared by microwave assisted ultrasonic separation. • The thin Bi₂MoO₆ nanosheets could be more favorable to charge shift and separation. • The WO₃/thin Bi₂MoO₆ exhibits superior photoelectric activity than WO₃/Bi₂MoO₆ film. • The efficient photoelectric property results from facilitated charge separation. - Abstract: Thin Bi₂MoO₆ nanosheets are obtained by a microwave-assisted ultrasonic separation process. After exfoliation, the thinner and uniform nanosheets with a thickness of about 10 nm were obtained. The exfoliated nanosheets would provide many amazing functionalities such as high electron mobility and quantum Hall effects. Therefore, thin Bi₂MoO₆ supported on WO₃ electrode (WO₃/thin Bi₂MoO₆) exhibits facilitated charge separation than pure WO₃ film and the un-exfoliated Bi₂MoO₆ nanosheets supported on WO₃ electrode (WO₃/Bi₂MoO₆). As a result, WO₃/thin Bi₂MoO₆ shows remarkably stable photocurrent density of 2.2 mA/cm² at 0.8 V_SCE in 0.1 M Na₂SO₄ which is higher than that of that of WO₃ (1.1 mA/cm²) and WO₃/Bi₂MoO₆ (1.5 mA/cm²).