Highly active Fe-doped ZIF-8 nanocatalyst in electrochemical degradation of pharmaceutical pollutant in neutral environment

Abstract

In this study, zeolitic imidazolate framework (ZIF-8) nanocatalyst was synthesized by the thermal solvent method and doped by Fe species through wet impregnation technique. The nanocatalysts were applied for the degradation of Phenazopyridine Hydrochloride (PHP) through the heterogeneous Electro-Fenton (HEF) process. The nanocatalysts were characterized by XRD, BET-BJH, FT-IR, FE-SEM, TEM, and acidimetric-alkalimetric titration techniques. The results showed the high surface area (1335 m2g-1) and homogenous dispersion of Fe species. The influence of different operating conditions was investigated, including pH level, nanocatalyst concentration, applied current, and PHP concentration. The optimum conditions for the HEF system over the Fe-ZIF-8 nanocatalyst were pH=7, 0.2 g L-1 of the Fe-ZIF-8 nanocatalyst, 100 mA, and 10 ppm of PHP concentration, which resulted in 99% PHP removal. The developed nanocatalyst had high reusability for the PHP removal in the HEF process. The results confirm the high potential of ZIF-8 nanocatalyst for pharmaceutical wastewater treatment through the HEF process.