Simultaneous S-scheme promoted Ag@AgVO₃/g-C₃N₄/CeVO₄ heterojunction with enhanced charge separation and photo redox...

Photocatalytic removal of toxic contaminants is one of the emerging techniques for water remediation, but it suffers from low redox ability, charge recombination and poor light harvesting efficiency. The present work reports a simultaneous S-scheme promoted by CeVO₄/g-C₃N₄/Ag@AgVO₃. The formation of the S-scheme mechanism enhanced the generation of photogenerated carriers and also improved the redox ability of the electrons and holes in the reduction and oxidation photocatalysts. The ternary demonstrated remarkable photo switching properties along with efficient charge separation which was achieved through dual interfacial interaction within the ternary (Ag@AgVO₃/g-C₃N₄ and CeVO₄/g-C₃N₄). The heterojunction formation was verified through the shift in binding energy spectra in the X-ray Photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy analysis (HR-TEM). The ternary demonstrated reduced PL intensity, width of space charge region and an upsurge in photogenerated current density in the order of 93 μA/cm2 (∼6X higher than all the pristine). This resulted in efficient removal of methyl orange, methylene blue and endocrine disruptive bisphenol-A with a removal rate of 0.02 min^-1, 0.03 min^-1 and 0.0087 min^-1 and an apparent quantum yield of 4.6 × 10^-9 (Methylene Orange), 6.89 × 10^-9 (Methylene Blue) and 2 × 10^-9 (Bisphenol A/H₂O₂).