Multifunctional Ag/AgCl/ZnTiO3 structures as highly efficient photocatalysts for the removal of nitrophenols, CO2 photoreduction, biomedical waste treatment, and bacteria inactivation

Abstract

Over the past few decades, biological hazards and organic pollution have become major environmental concerns. Photocatalysis has been found to be effective in minimizing the negative impacts of these issues in air and water. Lozenge shape Ag/AgCl/ZnTiO3 photocatalysts were fabricated by a facile two-step synthesis method, including hydrothermal and coprecipitation. The physicochemical characteristics and morphological properties of the structures were comprehensively described taking advantage of a multi-technique approach. The prepared photocatalysts offered excellent nitrophenol mineralization (>90%) after 90 min of visible light irradiation. Based on the spin-trapping ESR technique, •O2̅– was recognized as the eminent reactive species during the photocatalytic process. Interestingly, the plasmonic Ag/AgCl/ZnTiO3 photocatalyst presented promising CO2 to CO/CH4 conversion with a production rate of 95.0/18.5 μmol.g−1.h−1 under visible light irradiation, which is about 1.6 times higher than that of ZnTiO3, implying the synergetic effects due to Ag/AgCl in the ternary construction. In addition to the investigation of antibacterial activity, the prepared photocatalysts were successfully applied to treat the hazardous biological waste bearing U87-MG cancer cells under visible light for the first time. Several as-related analytical techniques were served to demonstrate the activity and interaction pathways. This work may hone a new insight into designing highly efficacious ternary photocatalytic materials.