Photocatalytic, antioxidant, and electrochemical behavior of one-pot hydrothermal synthesized chlorine and calcium co-doped tungsten(VI) oxide nanowires

Photocatalytic, antioxidant, and electrochemical properties of one-pot hydrothermal synthesized chlorine and calcium co-doped WO₃ nanowires (Cl-Ca@WO₃) were studied. The prepared WO₃-based nanowires were characterized using various analytical techniques. The UV–visible and Photoluminescence analysis showed that the band gap energy decreased from 2.49 eV for WO₃ to 1.80 eV for WO₃ nanowires that were co-doped with 4 % chlorine and 1 % calcium (4:1).Higher Scanning and Transmission Electron Microscopic analysis, showed that Cl-Ca@WO₃nanowires shapes changed and that they formed long and short bundles of nanowires based on the Cl-Ca mixing ratio. X-ray diffraction (XRD) analysis revealed a monoclinic phase even after the doping with Cl and Ca. The textural analysis showed an increase in surface area (4.216 m²g⁻¹ to 16.031 m²g⁻¹). The photoreaction method removed 31.94 % of the brilliant green dye by WO₃ nanowires and 88 percent using Cl-Ca@WO₃ at 240 min.The order of abundance of metals in the dyeing wastewater is Cu(1.76 ppm)> Cr (1.66 ppm)> Pb(1.26 ppm)> Ni (1.15 ppm) and the order of removal by each nanocatalyst at maximum time of 120 is as follows; WO₃: Cr> Ni> Cu> Pb, Cl-Ca@WO₃ (1:2): Cu > Cr > Ni > Pb, Cl-Ca@WO₃ (4:1): Cr > Cu > Ni > Pb.The pseudo-second-order model best described pollutant uptake and that Cl-Ca@WO3 was reusable after the fifth cycle. The antioxidant activity assayed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) revealed that Cl-Ca-WO₃ performed better with IC₅₀ value of 70.95 at 100 µg/mL. The electrochemical tests discovered that Cl-Ca-WO₃ nanowires have better kinetic performance and higher spontaneous energy than WO₃ nanowires.