Synthesis, characterization and photocatalytic dye degradation studies of novel defect pyrochlore, KHf0.5Te1.5O6

Abstract

In this study, KHf_0.5Te_1.5O₆ (KHTO) semiconductor has been synthesized by the solid-state method. The synthesized material is characterized using X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible diffuse reflectance spectroscopy, field emission-scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy and N₂ adsorption/desorption measurements. The material is found to be crystallized in a cubic lattice with the space group F<i>d</i><img src='/image/spc_char/3_bar.gif' border=0><i>m</i> . The bandgap energy of the KHTO is 2.6 eV. The photocatalytic activity of KHTO has been investigated by measuring the degradation of methylene blue (MB) and methyl violet (MV) dyes under the visible light irradiation. The mechanistic dye degradation pathway of MB has been studied. The radical quenching experiments reveal that the short-lived species O₂^●-, OH^●, and h⁺ actively participate in the degradation of MB and MV dyes. An additional terephthalic acid experiment has been carried out to establish the participation of OH^● radicals in the dye degradation. The stability and reusability of the KHTO catalyst are also studied.