Tailoring photocatalytic performance: the role of Cu-Ni concentration on electrospun Cu-Ni/TiO₂-PVA nanofibers under UV and sunlight irradiation

Abstract Recently, researchers have concentrated on enhancing the photocatalytic efficiency of TiO 2 by doping and co-doping it with various metals during the synthesis process. However, achieving an optimal dopant concentration is critical. This study explores the effects of copper-nickel (Cu-Ni) co-doping on the structural, morphological, optical, and photocatalytic properties of TiO 2 -PVA nanofibers (NFs). Cu-Ni/TiO 2 -PVA NFs were fabricated using sol–gel and electrospinning techniques at various dopant concentrations. XRD analysis revealed an anatase phase for all the samples, with the crystallite size and band gap decreasing from 23.00 nm to 18.91 nm and 3.11 eV to 2.76 eV, respectively, as the Cu-Ni dopant concentration increased. TEM analysis confirmed the lattice fringes with a 0.352 nm interplanar spacing corresponding to anatase TiO 2 . The sample with a dopant concentration of 0.5 wt% exhibited the highest photocatalytic degradation efficiency. Under UV irradiation, 97.49% degradation of methylene blue (MB) was achieved with a rate constant of 5.19 × 10 −3 min −1 , while under sunlight, 99.84% degradation was achieved with a rate constant of 16.97 × 10 −3 min −1 . Recyclability tests demonstrated consistent performance, with 85.66% MB degradation efficiency after six cycles. Scavenger tests identified holes as the primary active species responsible for photocatalytic activity. This study highlights the enhanced photocatalytic performance, stability, and reusability of Cu-Ni/TiO 2 -PVA NFs under UV and sunlight irradiation. These findings demonstrate the material’s potential for sustainable wastewater treatment applications, providing a cost-effective and environmentally friendly solution for organic pollutant removal.