G-C3N4/Ag@CoWO4: A novel sunlight active ternary nanocomposite for potential photocatalytic degradation of rhodamine B dye

Present study reports the fabrication of novel sunlight active heterogeneous photocatalyst, i.e. Ag@g-C3N4/CoWO4 for potential degradation of rhodamine B dye. The ternary nanocomposite was fabricated using thermal condensation of melamine to prepare g-C3N4 followed by coupling with silver doped cobalt tungstate (Ag@CoWO4) using the hydrothermal method. The novel composite photocatalyst (Ag@g-C3N4/CoWO4) along with pristine photocatalysts (g-C3N4 and Ag@CoWO4) were well characterized in term of morphology (scanning electron microscopy), structure (Fourier Transformed Infrared spectroscopy), crystallinity (X-ray diffraction), and composition (energy dispersive X-ray). The energy band gaps of catalysts were calculated using UV-visible spectroscopic analysis (Tauc plot). The characterization analysis supports the successful assembly of Ag@CoWO4 nanoparticles on the surface of g-C3N4 nanosheets with good crystallinity. The photocatalytic potential of novel catalysts was examined through the degradation of rhodamine B dye in water. The engineered heterojunction promotes photocatalytic activity and improves photo-generated charge separation. The results of the proposed research showed boosted sunlight active photocatalytic efficiency (97% in 120 min at pH 6) of novel composite against rhodamine B dye degradation. The kinetics of the reaction was determined using different models and RSM was used as a statistical tool for interaction and individual effects of influencing parameters. The numerical values of optimized parameters endorsed the results of RSM i.e. composite dose = 10mg/100 mL, H2O2 = 15 mM, and pH = 6.