Synthesis of a plasmonic AgCl and oxygen-rich BiOCl composite heterogeneous catalyst for enhanced degradation of tetracycline and 2,4-dichlorophenoxy acetic acid.

In this study, a AgCl/BiOCl composite heterostructure was constructed. Varying ratios of AgCl nanoparticles were immobilised onto the BiOCl rod-like structure. The physical and optical properties of the synthesised catalysts were characterised using a range of techniques. The photocatalytic activity of the catalysts was investigated by the degradation of 2,4-dichlorophenoxy acetic acid (2,4-D) and tetracycline (TC) under visible light irradiation. The performance of the composite photocatalysts was 18 and 3.4 times better in 2-4,D and TC photodegradation when compared to BiOCl alone. The improved photocatalytic performance was due to the surface plasmon resonance (SPR) effects of the Ag nanoparticles deposited on the surface of the wt%AgCl/BOC thereby improving the separation of the electron-hole pair. The effects of the initial contaminant concentration, pH, photocatalyst loading were investigated. Trapping experiments were also carried out to deduce the reactive species responsible for the degradation process and a preliminary mechanism of degradation was proposed. Successful mineralisation of 2,4-D and TC at 65% and 63% efficiency was also measured after 24 h and the potential for reusability of the as-synthesised photocatalyst was established. This work reports a promising heterogeneous photocatalyst for the removal of pollutants such as TC and 2,4-D from wastewater.