Synthesis,characterization, and performance assessment of a perovskite-type nano photocatalyst for degradation of thiamethoxam

It is essential to remove thiamethoxam (THMX) from surface water as it negatively impacts the ecology and neurological systems of insects. Hence, a study was conducted to degrade THMX with different compositions of LaFeO₃/g-C₃N₄ (LFCN) composites. Several methods, including X-ray powder diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), and field emission scanning electron microscopy (FESEM), were applied to characterize the synthesized photocatalyst. The influence of many parameters on degradation, for example, THMX concentration, dosage of catalyst, and pH were studied experimentally. The degradation was highest under both UV-C and sunlight for the synthesized catalyst, 1% LaFeO₃/g-C₃N₄ (LFCN1), in comparison to graphitic carbon nitride (g-CN), and bare lanthanum ferrite (LF). The degradation was around 95% for LFCN1 under UV-C light having an intensity of 15 W/m² whereas degradation was 71.8% with LFCN1 photocatalyst under sunlight at neutral pH in 120 min of reaction time. The increased activity of LFCN1 was attributable to an improved surface area and a lower band gap. The study of reaction kinetics indicated second-order behaviour. Additionally, a probable mechanism for degradation was put forth.