Hydrothermal synthesis and photocatalytic performance of Dy₂O₃/Mn nanostructures

Semiconductor photocatalysts have been widely used to catalyse photochemical reactions for the remediation of wastewater contaminated with organic dyes. This study aimed to synthesise and characterise manganese-doped Dy₂O₃ (Dy₂O₃/Mn) nanostructures as possible catalysts with improved photocatalytic properties. A low-cost hydrothermal method was used to fabricate materials with optimal morphological and structural properties. Before characterisation, Dy₂O₃/Mn nanostructures were subjected to heat treatments in the range 300–600 °C. X-ray diffraction analysis revealed that all samples exhibited a cubic phase structure; the crystallite size varied between 30.7 and 40.2 nm with the calcination temperature. Scanning electron microscopy, energy-dispersive spectroscopy, and Fourier transform infrared spectroscopy were used to examine the morphology and chemical content of the nanostructures, and the efficacy of the elaboration approach was validated. Diffuse reflectance spectroscopy demonstrated the visible-light absorption of the samples, and the bandgap energy was determined to be approximately 2.9 eV. Methylene blue (MB) dye was used to examine the photocatalytic activity of the Dy₂O₃/Mn nanostructures under visible-light irradiation. After 360 min, 92% of MB was degraded. The doping of Dy₂O₃ with Mn improved both the photocatalytic activity and the overall properties of the catalyst. Therefore, Dy₂O₃/Mn nanostructures could replace current catalysts for the degradation of organic dyes in wastewater. Graphical abstract: [Figure not available: see fulltext.].