Preparation of novel ternary g-C_3N_4/WO_3/ZnO nanocomposite adsorbent with highly effective imidacloprid removal: optimization design and a controllable systematic study

摘要

In this study, a novel g-C_3N_4/WO_3/ZnO nanocomposite was successfully synthesized from two-dimensional (2D) g-C_3N_4 and WO_3 nanosheets and one-dimensional (1D) ZnO nanorods. These nanostructures were characterized by the related analyses of field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, mapping, X-ray diffraction, and Fourier transform infrared spectroscopy. The obtained results further demonstrated the successful synthesis of the ternary heterostructure. The final productions were used as an effective adsorbent for imidacloprid pesticide removal from aqueous solution. Also, 2~(k-1) factorial design was applied to systematic study the effects of various experimental parameters such as the amount of adsorbent, imidacloprid concentration, contact time, and pH on the adsorption behaviors. According to the results obtained from the analysis of variance, these experimental parameters have significant effects on the imidacloprid adsorption efficiency. Also, response surface methodology was used to attain the best optimization procedure of imidacloprid adsorption. The results showed that g-C_3N_4/WO_3/ZnO nanocomposite has a significant potential for imidacloprid removal with an efficiency of 99.9%. The appropriate kinetic model for imidacloprid adsorption on the g-C_3N_4/WO_3/ZnO nanocomposite was pseudo-second-order kinetic models. Also, Freundlich isotherm was fitted for performing the adsorption process. The nanocomposite developed in this study and also the optimization procedure can be used as a novel strategy in the green future.