Efficient ZnCr LDH/monoclinic‐WO₃ composites for Degradation of Tetracycline under Visible Light

Abstract

Recently, efficient removal of antibiotics like Tetracycline (TC) from wastewater is emerging as a crucial problem. However, low adsorption capacity and high cost of photocatalysts limit their utility. In this context, monoclinic tungsten trioxide (WO3) loaded ZnCr layered double hydroxide (LDH) composites (ZnCr‐xWO3 x=10 and 20 %) are prepared by co‐precipitation method and characterized by several techniques viz. X‐Ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Raman, Photoluminescence (PL), Field‐Emission Scanning Electron Microscopy (FE‐SEM), Brunauer Emmett Teller (BET), Diffuse Reflectance Spectroscopy (DRS) and Dynamic Light Scattering (DLS). The XRD pattern confirms the formation of ZnCr LDH and its composites with monoclinic‐WO3. Bond vibrations and phase transitions were explored with the help of FTIR and Raman spectra. The BET analysis for ZnCr LDH and ZnCr‐10WO3 composite shows surface area as 27.439 m2/g and 47.691 m2/g. The higher photocatalytic performance of the composites formed is due to enhanced specific surface area and better separation efficiency of photo‐generated electrons and holes through conventional class II hetero junction between ZnCr LDH and monoclinic‐WO3. The kinetics studies performed shows better fit for pseudo first order reaction with maximum degradation efficiency and rate constant for ZnCr‐10WO3 (i. e., 86.7 % and 1.5×10−2 min−1).