Surface modification of heterostructured Bi8W4O24/ZrO2@GO composite via low-pressure cold plasma for boosting photocatalytic potential against Basic fuchsin and Bismarck brown Y dyes.

Abstract

The widely used dyes, Basic fuchsin (BF) and Bismarck brown Y (BBY), pose significant risks to water resources and human health, necessitating efficient removal methods. Semiconductor-based heterogeneous photocatalysis offers an eco-friendly solution. However, improving the photocatalyst's efficiency remains a challenge. This study aims to fabricate a promising Bi₈W₄O₂₄/ZrO₂@GO (BWOZG) heterojunction via hydrothermal approach, followed by low-pressure cold plasma (LPCP) treatment to improve its properties for environmental remediation of BF and BBY dyes along with industrial wastewater. The prepared composites were analyzed via DLS, UV-visible spectroscopy, SEM-EDX, FTIR, XRD, and EPR. The findings indicated that the LPCP-treated BWOZG has z-average of 225 ± 5 nm, zeta potential of - 38.74 ± 2 mV, band gap of 2.20 eV, a porous morphology, and mixed orthorhombic Bi₈W₄O₂₄ and tetragonal ZrO₂ phases. LPCP-treated BWOZG composite exhibited 5% increase in degradation efficiency of BF (99.7%) at pH = 6, catalyst dose = 20 mg L^-1, dye dose and irradiation time = 10 mg L^-1/30 min, and 6% for BBY (98%) at pH = 5, catalyst dose = 30 mg L^-1, dye dose and irradiation time = 10 mg L^-1/30 min, and 80.41% reduction in COD of industrial wastewater. The successful degradation of dyes to nontoxic species was confirmed by FTIR. The formation of ^•OH and O₂^-• radical species during photocatalytic process was confirmed by EPR analysis. Kinetics study showed the best fitness of the pseudo-first-order model on experimental data. LPCPT-BWOZG retained 91 and 89% recyclability after five cycles of BF and BBY degradation, respectively, and good broad-spectrum bactericidal activity for E. coli and S. aureus, demonstrating its potential as antibacterial photocatalytic materials for oxidation of organic pollutants in aqueous media to enhance the environmental safety.