Surfactant-assisted formation of robust p-Ag₂O – n-BaTiO₃ heterojunctions for visible-light photocatalytic applications

This paper reports the use of microwave-assisted hydrothermal and precipitation approaches to prepare a composite from a polyethylene glycol (PEG − 10000) surfactant-assisted dispersion of p-Ag₂O particles in conjunction with n-BaTiO₃ (n-BTO) for use in visible-light photocatalytic applications. The conductivities of p-Ag₂O and n-BTO were determined through Mott–Schottky measurements and verified using energy band diagrams. Various PEG − 10000-treated and untreated (1 − x)BTO − xAg₂O (x ≈ 57.0, 63.0, and 75.0 mol%, determined using Rietveld refinement) composites were prepared. X-ray photoelectron spectroscopy was used to determine the valence states and binding energies of the constituent elements in the various composites. Scanning electron microscopy, transmission electron microscopy, and particle-size distribution measurements revealed that Ag₂O is excellently dispersed in the PEG − 10000-treated composite, which exhibited a remarkable surface area (≈10 m²⋅g⁻¹) and pore volume (≈0.05 cm³⋅g⁻¹) at x ≈ 63.0 mol%. All composites exhibited effective and reliable visible-light energy-harvesting capabilities. The PEG − 10000-treated composite (x ≈ 63.0 mol%) exhibited the most promising rhodamine B photodegradability, attributable to the formation of abundant p − n junctions and the effective absorption of visible light. An energy-band diagram was constructed to elucidate the potential mechanism responsible for this remarkable activity. Under visible light, our samples outperformed other similar and representative literature-reported samples under solar light.