Ultrasonic degradation of selected dyes using Ti3C2Tx MXene as a sonocatalyst.

Abstract

MXene, a new family of two dimensional materials, was utilized as a sonocatalyst in an ultrasonic treatment (US) process for removal of methylene blue (MB) and acid blue 80 (AB). The physico-chemical properties of MXene were characterized using scanning electron microscopy, transmission electron microscopy, porosimetry, and a zeta potential analyzer. Degradation of dyes by US was systemically investigated under several experimental conditions including: power density of US (45, 90, 135, and 180WL-1), frequency of US (28 and 970kHz), pH of dye solution (3.5, 7, and 10.5), solution temperature (293, 303, and 313K), and addition of hydroxyl radical promotor (H2O2) and scavenger (t-BuOH) to concentrations of 25mM. Based on the experimental results, the quantity of H2O2, which was used as an indicator of hydroxyl radical concentration, was an important factor in determining the degradation rate of MB and AB in this US study. Additionally, synergetic indices for removal of both dyes were higher than 1.0 in all cases, indicating the outstanding efficiency of MXene as a sonocatalyst in the US reactor for removal of both, due to an increase in both (i) the quantity of H2O2 in the US reactor and (ii) active sites for adsorbates from dispersion effects. A stability test on MXene in the US process was conducted using X-ray diffraction and five-cycle recycling performance tests. Based on our experimental data, MXene can be utilized as a sonocatalyst in the US process for a high removal rate for dyes (e.g., MB).