Mixed-calcination synthesis of Bi2MoO6/g-C3N4 heterojunction with enhanced visible-light-responsive photoreactivity for RhB degradation and photocurrent generation

Abstract

Organic-inorganic hybrid photocatalyst Bi2MoO6/g-C3N4 was synthesized via a mixed-calcination route based on intimate interfacial interaction. The successful combination of g-C3N4 and Bi2MoO6 was verified by X-ray diffraction (XRD), Fourier-transform infrared spectra (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) mapping. The optical property of the as-prepared photocatalysts was characterized by UV⿿vis diffuse reflectance spectra (DRS). The photocatalytic activities were investigated by degradation of Rhodamine B (RhB) and photocurrent generation under visible-light (λ>420nm). The results demonstrated that the Bi2MoO6/g-C3N4 composite exhibits highly enhanced photoreactivity compared to the pristine samples. It should be attributed to the fabrication of a Bi2MoO6/g-C3N4 heterojunction, thus resulting in the high separation and transfer efficiency of photogenerated charge carriers, as confirmed by the photoluminescence (PL) and electrochemical impedance spectra (EIS). The active species trapping experiments indicated that holes (h+) and superoxide radicals (O2⿿) are the main active species in the degradation process.