Graphitic carbon nitride (g-C3N4) decorated ZnWO4 heterojunctions architecture synthesis, characterization and photocatalytic activity evaluation

Herein, efficient ZnWO4/g-C3N4 hybrid photocatalysts with effective interfaces were designed by controlling the surface charges of the two individual materials via facile hydrothermal method. The photocatalysts were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive X-ray (EDX) analysis, Raman, N2 adsorption-desorption, Photoluminescence spectroscopy (PL) and UV–Vis diffuse reflectance spectra analysis. XRD and TEM results indicate the reasonable existence of g-C3N4 (001)-ZnWO4 (010) interfaces. The incorporated g-C3N4 layer has shown a great impact on the structure and properties, including lattice expansion, band-gap narrowing, luminescence enhancement, as well as photocatalytic activity. Visible light induced photocatalytic degradation test was carried out for all the synthesized catalysts towards rhodamine B (RhB) and 4-chlorophenol (4-CP) dyes. The results reveal that the hybrid catalyst show outstanding degradation efficiency of 99%, high apparent constant (0.0931 min−1) and long term stability towards RhB dye under visible light irradiation. The degradation efficiency is only ~41 and 47% for the pure g-C3N4 and ZnWO4 catalysts, respectively. The synergic effect between these hybrid materials photocatalytic mechanism was also discussed in brief.