Abstract
The frequent occurrence of antiviral drugs, such as nevirapine (NVP) in water bodies is a significant ecotoxicological risk. Available water treatment technologies are not able to completely remove these antiviral drugs due to their chemical stability and are non-biodegradable.
Photocatalysis as one of the advanced oxidation processes, is environmentally friendly and promising technology for degradation of antiviral drugs. Recovery of photocatalysts after use remains a challenge, this can be mitigated by immobilizing the photocatalyst into membrane to form photocatalytic membrane.
The present work developed a photocatalytic membrane and evaluated its efficiency in synergistically degrading and removing NVP from synthetic water. The photocatalyst employed herein (WO3, ZnIn2S4) were fabricated via hydrothermal method. WO3 and ZnIn2S4 are oxidation and reduction photocatalyst respectively, viable in making S-scheme heterostructure with minimized charge recombination and enhanced redox potential. Vanadium carbide Mxene (V2CTx) was used as a cocatalyst to further improve the effectiveness of charge separation at the interface of WO3/ZnIn2S4 S-scheme heterostructure via formation of ternary heterostructure (V2CTx@WO3/ZnIn2S4). The pristine, binary, and ternary photocatalyst were then used to fabricate cellulose acetate based photocatalytic membrane via phase inversion.
X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL) analysis were done to investigate the physiochemical characteristics of the prepared photocatalysts. PL demonstrated low charge recombination for ternary composites as compared to pristine WO3 and ZnIn2S4, 5% VWZ recorded the lowest charge transfer resistance evidenced by small arc radius in electron impedance spectroscopy (EIS). Work functions obtained from XPS for ZnIn2S4, WO3, and V2CTx were 6.68, 7.08, and 8.70 eV respectively, confirming S-scheme band structure with electron migrating from ZnIn2S4 to WO3 elucidated by changes in binding energies...