Ball mill-induced piezocatalysis assessment for dye degradation using BiVO4

Abstract

The process of mechanochemical ball milling, carried out at a temperature of 600 °C for a duration of 4 h, yielded a single phase of BiVO4 powder. This powder was subsequently evaluated as a catalyst for the purpose of methylene blue (MB) dye degradation. The formation of phase was confirmed through the use of X-ray diffraction and Raman spectroscopy. The use of a scanning electron microscope facilitated the verification of the existence of grains exhibiting irregular morphologies. During a 40-minute investigation of piezocatalysis utilising ball milling, it was observed that the MB degradation efficiencies of the 0.6 g BV and control samples were approximately ∼86% and ∼17%, respectively. The degradation efficiencies of MB for the samples containing 0.6 g BV and without sample (control) were approximately ∼32% and ∼16%, respectively, following a 180-minute piezocatalysis evaluation that utilised ultrasonication. The utilisation of piezocatalysis in the operation of a ball mill for the assessment of 0.6 g BiVO4, utilising 15 yttria-stabilized zirconia balls, has resulted in a remarkable degradation constant (k) value of 0.0476 min−1. The scavenger test results indicate that the ball mill-assisted piezocatalysis mechanism for MB dye degradation is primarily driven by the active species of superoxide radicals (•O2−).