Enhanced photocatalytic degradation of harmful pollutants by MoO3/SiO2/MXene nanocomposite powder catalyst

Abstract

The search for materials to treat wastewater is especially crucial. Herein, we have prepared 1D molybdenum oxide (MoO3) nanobelts through a hydrothermal approach. The binary (MoO3/SiO2) and ternary composites of MoO3/SiO2/MXene were synthesized via ultrasonication route. The as-prepared MoO3, MoO3/SiO2, and MoO3/SiO2/MXene composites were employed to investigate the photocatalytic behavior of two organic dyes, methyl orange (MO) and crystal violet (CV). The % degradation of MO in the presence of MoO3 nanobelts and MoO3/SiO2 was calculated to be 48.9 % and 74.4 %, respectively. In the case of CV dye, the degradation (%) was observed at 53.7 % and 75.9 %. The MoO3/SiO2/MXene composite revealed the best photocatalytic behavior against both MO and CV dyes by removing 94.7 % and 97.7 % under visible light irradiation. The rate constant values of MoO3 nanobelts, MoO3/SiO2 and MoO3/SiO2/MXene composite for MO dye were calculated to be 0.00568 min−1, 0.01156 min−1, and 0.02399 min−1 and for CV dye 0.00679 min−1, 0.01208 min−1, and 0.02798 min−1 respectively. A scavenging test was carried out to monitor the main photo-active species that take part during the photocatalysis and hydroxyl radicals were found to be the highly active species during whole photodegradation progression. The SiO2 particles function as a good adsorbent medium and transfer the adsorbed organics toward more active sites to advance the reaction. 2D MXene nanosheets, as good conductors, reduce the recombination rate of charges, offer large surface area, and facilitate fast transfer of charges. The results suggest that MoO3/SiO2/MXene composite is a potential contender for wastewater remediation applications.