In-site growing honeycombed integrated S-doped-g-C3N4-NiCo2O4 PMS activator for round-the-clock ultra-efficient degradation of multiple pollutants

Given the pressing environmental crisis, there is an imperative to develop robust and efficient technology for treating high concentrations and diverse pollutants in water. Herein, honeycombed integrated S-doped-g-C₃N₄-NiCo₂O₄ catalysts were fabricated via a one-step in-situ growth method, which was utilized to activate PMS, enabling the ultra-efficient degradation of diverse high concentration pollutants within an extremely short period under both light and darkness conditions. Specifically, 10 mg of optimal catalyst can degrade 50 mg/L of tetracycline, rhodamine B, methylene blue, methyl orange, metronidazole and ciprofloxacin with degradation rates of 100 % (1 min), 99.9 % (5 min), 100 % (5 min), 98.1 % (5 min), 98.1 % (5 min) and 99.6 % (5 min), respectively. The TOC removal rate for tetracycline reached 61.9 %, suppressing that achieved by CN alone (7.7 %). The effects of various key parameters (initial TC concentration, PMS concentrations, initial pH, anions, different water bodies and humic acid, stability and practicality in the round-the-clock degradation system were systematically investigated, and the two degradation mechanisms for both dark and light conditions were proposed. The degradation intermediates and their toxicity evaluation were investigated via the example of TC degradation combined with DFT theoretical calculations and three-dimensional excitation-emission matrix fluorescence spectra. This work offers a novel paradigm to design PMS activator for round-the-clock ultra-efficient degradation of multiple pollutants, which reveals great potential for water pollution remediation.