Visible-light-driven photocatalytic degradation of methyl parathion as chemical warfare agent simulant by NiO/Bi2MoO6 heterojunction photocatalyst

Chemical warfare agents are considered the most lethal and sinister pollutants with incapacitating effects on humans and the environment. This study has reported a new NiO/Bi2MoO6 heterojunction photocatalyst capable of degrading methyl parathion (MP) as a nerve agent simulant. The NiO/Bi2MoO6 photocatalyst with nanoscale morphology was prepared using a solvothermal method and characterized using FE-SEM, EDS, TEM, HRTEM, XRD, UV-Vis spectroscopy and photoelectrochemical measurements. The conjugation of NiO with Bi2MoO6 nanostructures decreased the bandgap energy from 2.88 and 2.61 eV. The photoluminescence studies proved that the recombination of the charge carriers is slower in NiO/Bi2MoO6 nanocomposite compared to the pristine Bi2MoO6. Response surface methodology was used to consider the effect of pertinent factors (such as time, organophosphate concentration, pH, and photocatalyst dosage on the degradation reaction of MP. The photodegradation of the organophosphorus compound follows pseudo-first-order kinetics with a high rate constant of 1.7 × 10−3 min−1. According to the obtained results, NiO/Bi2MoO6 photocatalyst degraded more than 95% of MP around 120 min. The synthesized nanocomposite showed favorable performance for removing chemical pollutants with potential applications in visible-light-induced environmental remediation.