In-situ fabrication of MoO3 hexagonal flowers decorated with Co3O4 microrods with enhanced photocatalytic activity and stability under visible light irradiation

In the recent years, semiconductor photocatalyst has become an environmentally friendly solution for the oxidative elimination of emerging wastewater contaminants under visible light irradiance. Though, the large bandgap energy (Eg) and fast recombination of charge carriers are still problems for the definite application. Here, excellent photocatalytic activity of MoO3 based photocatalyst was explored by decorating Co3O4 microrods with MoO3 hexagonal flowers with lower concentrations (1.0, 3.0, 5.0, 7.0 wt%) of Co3O4 to form novel p-n heterojunctions of Co3O4/MoO3 via hydrothermal synthesis. The as-synthesized 3% Co3O4/MoO3 nanocomposite revealed enormously improved visible light photocatalytic activity for the degradation of rhodamine B (RhB) and alizarin yellow (AY) dyes as compared to other samples due to the development of the p-n junction between p-Co3O4 and n-MoO3. The improved 3.0 wt% Co3O4-loaded MoO3 had a total removal of 91% RhB and 67% AY after 120 min of visible-light exposure with high recyclability and stability after five cycles. The developed p-n heterojunction between 3.0 wt% Co3O4 and MoO3 decreases Eg up to 2.16 eV, shows broader visible light absorption and improved photocharge separation as compared to pristine MoO3. The utilization of this novel heterojunction photocatalyst for the degradation of both dyes is the focus of this research. Furthermore, the trapping experiments and enhanced photocatalytic mechanism was proposed also.