Bio-inspired ZnWO4−x exhibiting vacancy-driven UV-to-NIR photodegradation of antibiotics in wastewater

Abstract

Complex structures of antibiotics inhibit their breakdown by conventional removal techniques, resulting in persistent environmental pollution and breeding of deadly bacteria, that pose disastrous human health implications. As a remedy, we prepared BW-ZnWO4−x photocatalyst by combining Papilio paris (P. paris) wings as supporting substrates and templating frameworks and oxygen vacant ZnWO4 through modified functionalization and solvothermal processes. The BW-ZnWO4−x photocatalyst exhibited narrowed bandgap, broader photo-absorption, ∼6-fold high surface area and inhibited charge carrier recombination. Consequently, BW-ZnWO4−x photocatalyst degraded 98 %, 94 % and 85 % of levofloxacin (LVFX) antibiotic and 96 %, 93 % and 83 % of tetracycline (TC) antibiotic under ultraviolet (UV), visible and near-infrared (NIR) irradiation, respectively in 60 min. Comparatively, hydrothermally synthesized pristine ZnWO4 photocatalyst (denoted: P-ZnWO4) degraded 83 %, 82 %, 59 % of LVFX antibiotic and 85 %, 79 %, 50 % of TC antibiotic under UV, visible and NIR light irradiation, respectively. Moreover, the BW-ZnWO4−x photocatalyst demonstrated real-world applicability by degrading 95 %, 92 % and 78 % of hexavalent chromium (Cr VI) under UV, visible and NIR light irradiation, respectively. Therefore, these results could be insightful in development of bio-inspired materials for solar harvesting and storage systems, security systems and water treatment applications.