Synthesis of g-C3N4/BiVo4 nanocomposite photocatalyst and its application in photocatalytic reduction of CO2

Abstract

A visible-light-active graphitic-like carbon nitride (g-C3N4)/BiVO4 nanocomposite photocatalyst was synthesized using a facile ultrasonic dispersion method. The nanocomposite was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence (PL) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and photocurrent response measurements. The photocatalytic activity in the photoreduction of CO2 under visible-light irradiation (λ>420 nm) was determined. The g-C3N4/BiVO4 catalyst containing 40% (w) g-C3N4 showed the highest photocatalytic activity; it was almost twice that of g-C3N4 nanosheets and four times that of BiVO4. The enhanced photocatalytic activity is attributed to the formation of heterostructures at the g-C3N4/BiVO4 interface and appropriate alignment of the energy levels between them, which can facilitate separation of photogenerated electrons and holes.