Green approach to g-C3N4/Zn2V2O7 nanocomposites synthesis using salvia hispanica powder for photocatalytic degradation of dyes and organic catalysis

Two-dimensional mixed metal oxides have been of interest recently, owing to their distinctive crystal structures and multifunctional properties. This article presents a green and sustainable synthesis approach for zinc vanadate (ZNV) nanoparticles (NPs) using chia seed powder by a green solution combustion method. The synthesized ZNV NPs were then employed for the preparation of g-C3N4/Zinc vanadate (ZNVG) nanocomposites (NCs) at 10 %, 20 %, and 30 % of g-C3N4 compositions. XRD, FT-IR, SEM, EDAX, UV-Vis, and PL techniques have been performed to characterize the materials entirely. The size of crystallites calculated through the Debye-Scherrer equation for 10 %, 20 %, and 30 % g-C3N4 doping content are 40 nm, 38 nm, and 37 nm, respectively. UV-Vis spectroscopy shows the redshift in the absorption wavelength and a reduction in the band-gap energy with enhanced light- harvesting features for higher g-C3N4 contents. Photocatalytic investigations have shown that the performance of ZNVG-20 nanocomposite is the optimum; with remarkable degradation efficiencies of 94 % of Rose Bengal and 97 % of Methylene Blue dyes after 180 min. Excellent degradation results were obtained for mixed dyes containing Rose Bengal, Methylene Blue and Methyl Orange and also for environmentally challenging substrates such as rangoli colors. Interestingly, the ZNVG composites also acted as good catalysts in the Knoevenagel condensation reaction, which exhibited up to 92 % efficiency under blue light irradiation. The present findings indicate the versatile potential of ZNVG nanocomposites as photocatalysts and catalysts for addressing environmental and synthetic challenges in a sustainable manner.