Strategic bandgap tuning of WO3 nanoparticles for superior visible-light-driven photocatalytic degradation for water purification: an effect of Y3+doping

Abstract

Dye pollutants released from various industrial processes into wastewater are a significant environmental concern due to their chemical stability, toxicity, and resistance to conventional treatment methods. Advanced photocatalytic techniques have emerged as effective solutions for degrading these persistent organic compounds. While semiconductor-based photocatalysis is a highly promising method, the efficiency of most photocatalyst is hindered by their poor absorption of visible-light and fast charge recombination. To overcome these challenges, yttrium (Y³⁺)-doped WO₃ nanoparticles were synthesized using a chemical co-precipitation method and thoroughly characterized to assess their structural, morphological, elemental, and optical properties. Various analytical techniques, including X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and UV–Vis spectroscopy, were employed for detailed analysis. The XRD spectra confirm the formation of monoclinic WO₃ (m-WO₃) nanoparticles with high phase purity, as evidenced by the absence of any secondary phases or impurity peaks. Photoluminescence (PL) analysis showed that Y doping enhanced the separation of photo-induced charge carriers, improving the photocatalytic performance. The Y-doped WO₃ nanoparticles demonstrated exceptional photocatalytic efficiency, effectively degrading the organic dye malachite green (MG) under visible-light irradiation. Specifically, the 6% Y-doped WO₃ nanoparticles exhibited a 90% removal of MG under visible-light irradiation with a rate constant of 0.01361 min⁻¹. Additionally, the catalyst displayed remarkable stability and reusability, maintaining its performance over five cycles. These results highlight the significant potential of Y-doped WO₃ nanoparticles as effective photocatalysts for environmental remediation and energy conversion applications, offering a promising solution for water purification and pollutant removal.