Increasing the photocatalytic efficiency of ZnWO4 by synthesizing a Bi2WO6/ZnWO4 composite photocatalyst

In the present study, a Bi2WO6/ZnWO4 photocatalyst was successfully constructed by a modified hydrothermal synthesis method with different molar concentrations of Bi2WO6 with respect to ZnWO4. The variation in molar concentrations of Bi2WO6 changed the photocatalytic properties of the Bi2WO6/ZnWO4 catalyst. The synthesized Bi2WO6/ZnWO4 photocatalyst was characterized by various techniques to decipher its structural and spectral properties. The interaction of Bi2+ ionic charge carriers and many-body effects cause the band gap to narrow in Bi2WO6/ZnWO4, as shown by PL analysis. The decrease in band gap energies (Eg) from 4.7 eV (ZnWO4) to 3.5 eV (30% Bi2WO6/ZnWO4) is beneficial because less energy is required to excite the valence electrons. The maximum degradation of Plasmocorinth B dye was found with 30% Bi2WO6/ZnWO4 under UV irradiation. This increased activity of 30% Bi2WO6/ZnWO4 can be attributed to the (i) synergistic effect in the bicrystalline framework of Bi2WO6 and ZnWO4, (ii) the high close contact between Bi2WO6 and ZnWO4, and (iii) the small crystallite size. The photocatalytic activity of synthesized Bi2WO6/ZnWO4 photocatalyst shows its significant potential in water/wastewater treatment application.