Highly efficient adsorption assisted photocatalytic decontamination of metronidazole by Co3O4 doped graphitic carbon nitrides

Since traditional wastewater treatment techniques only partially remove antibiotics like metronidazole (MTZ), the rising use of these drugs causes their entry into wastewater and receiving surface waterways. A flexible method that may effectively degrade such organic pollutants is adsorption assisted photocatalytic degradation. Herein, an easy mixing-and-heating procedure was used to synthesize visible light-induced g-C3N4/Co3O4 heterojunction photocatalysts. The structural properties and morphology of as-prepared materials were measured using characterization techniques such as FTIR, FSEM, and XRD analysis. The as-prepared catalyst has demonstrated a remarkable adoption and photocatalytic performance in degrading MTZ. It was found that 0.2 weight percent of Co3O4 was the optimum amount for achieving the best photocatalytic efficiency. A key factor in boosting photo-generated carrier separation is the synergistic interaction between g-C3N4 and Co3O4. The kinetics study of MTZ adsorption and degradation as well as factors effecting such as pH (2-10) and catalyst dosage process were investigated. The functional treatment method attained 78% degradation of MTZ under the following general conditions: pH = 6, g-C3N4/Co3O4 = 0.04 g/L, and reaction time = 200 min and MTZ concentration = 20 mg/L. A possible mechanism for the photocatalytic degradation was introduced, wherein O2•− was found to be the leading radical, whereas h+ and  HO• radicals contribute moderately to the degradation process. The research presents an appealing and environmentally friendly technique for the practical remediation of waste water carrying antibiotics.