In this work, a facile ionic liquid-mediated method was utilized to fabricate an efficient photocatalyst for environmental remediation. The eco-friendly aspect of the treatment was explored through an in-vivo toxicity bioassay. ZnO particles, prepared by a combined solid state-pyrolysis method, were coated by 1-methyl-3-(oxiran-2ylmethyl)- 1H-imidazolium-3-chloride ([MOYI]Cl) ionic liquid. Then, Ag/AgCl species were grown on the surface to make a heterojunction system leading to efficient charge separation and light absorption extension to the visible domain. The products were characterized by XRD, FTIR, SEM, EDX, DRS, BET, and PL analysis. Photocatalytic performance of the nanostructures was evaluated by the degradation of 3-methyl-4-nitrophenol (from the semivolatile organic compounds, SVOCs, family) solutions under visible light. According to the results, the photocatalyst was able to completely degrade the pollutant and decrease the amount of COD from 210 to 32 mg/L within 90 min of the photoreaction. Reusability studies revealed that the degradation efficiency slightly decreased to 92% after five repetitive experiments. In order to investigate the eco-friendly aspect of the treatment procedure, an in-vivo bioassay was conducted to evaluate the acute toxicity of the contaminant solution, before and after the photochemical reaction, in terms of physical, biochemical and hematological markers of the laboratory rats. LC-MS analysis was applied to identify the chemical structure of the reaction products and propose the most probable reaction pathway. The results showed that the photocatalytic treatment over the prepared materials is an eco-friendly and reliable method to effectively transform such toxic contaminants into non-toxic or less harmful compounds.
