Synthesis, Characterization, and Photoluminescence Properties of High and Low-Temperature Dimorphs of Pb2WO5 Glass-Ceramic for Photocatalytic Application

Abstract

Abstract In this study, pure Pb 2 WO 5 with its two dimorphs, high temperature (HT) and low temperature (LT) forms, were successfully crystallized via melt-quenching technique in the system PbO. WO 3 . Al 2 O 3 . The influence of adding definite amounts of different transition metal oxides (TMO) such as ZnO, TiO 2 , CuO, MnO 2, and V 2 O 5 on the crystalline structure, optical, and photocatalytic activity were investigated. X-ray diffraction revealed a high degree of crystallization of pure Pb 2 WO 5 in undoped and ZnO, TiO 2 , CuO, and MnO 2 -doped samples. Only the V 2 O 5 -doped sample revealed crystallization of PbWO 4 beside Pb 2 WO 5 . LT- Pb 2 (WO 5 ) is the preferred isomorph in the undoped and ZnO, TiO 2 , CuO, and MnO 2 -doped samples, while HT- Pb 2 WO 5 is preferred in the V 2 O 5 -doped sample. Scanning Electron Microscopy (SEM) depicted an undeveloped rectangular pillar with a crystal size of 400–900 nm. Energy-Dispersive X-ray Spectroscopy (EDX) analysis certifies the existence of transition metal in the crystals at the expanse of Pb ions. Photoluminescence measurements under ultraviolet (UV) excitation revealed an emission band at 470 nm for undoped sample and exhibited a series of peaks spanning from 400 nm to 620 nm for doped samples. The International Commission on Illumination (CIE) chromaticity coordinates for all the samples are situated within the blue color region of the chromaticity diagram. The undoped sample displays CIE coordinates at (0.117, 0.091), corresponding to a deep blue hue; while the doped samples are shifted towards the light blue area of the chromaticity diagram. Utilizing ultraviolet-visible (UV-Vis) diffused reflectance, the optical bandgap energy (E opt ) for all glass-ceramic samples was estimated, revealing values within the semiconductor range (2.52–3.01 eV). Photocatalytic activity, evaluated through methyl orange (MO) degradation under UV light. The undoped sample revealed a higher degradation efficiency (33.7% after 3 h). This study is thus considered a significant step toward the facile synthesis of moderately efficient UV light novel photocatalysts, semiconducting materials, and photoluminescent glass-ceramics.