Vesicular BiVO4 nanostructures modified by g-C3N4 quantum dots for enhanced photocatalytic activity

Photocatalysis technology has been an available method to alleviate the improper discharge of dye wastewater by employing light energy to degrade the dye pollutants. Here, the vesicular BiVO4 hollow structures were modified by graphite phase carbon nitride quantum dots (CNQDs) to construct the BiVO4-based photocatalyst (BiVO4/CNQDs) for the enhanced removal of dye molecules. The CNQDs with a diameter of 2–5 nm evenly decorate on BiVO4 vesicles to construct the close interface of the BiVO4/CNQDs heterojunctions. Compared with vesicular BiVO4, the enhanced visible-light decomposition of methyl orange (MO) comes down to the coordination of different components, the C and/or N doping and hollow structure. This is helpful to increase surface area of bulk BiVO4, broaden light response, narrow band gap and obstruct charge combination. Especially, the up-conversion luminescence of the CNQDs can induce BiVO4 to generate more photo-excited electrons to participate in the MO photo-degradation reaction. The BiVO4/CNQDs heterojunctions with the unique hollow structure and excellent photocatalytic activity display the promising utilization in wastewater treatment.