Hydrothermal growth of MnCO3 and covalent organic framework on the surface of MXene with sodium alginate hydrogel for effective photocatalytic eradication of disinfected byproducts

A facile and environmentally friendly methodology was established to integrate MXene (TiNbC), manganese carbonate (MnCO 3 ), and a covalent organic framework (COF) into a sodium alginate (SA) matrix through hydrothermal and crosslinking process, resulting in the successful fabrication of a novel TiNbC/MnCO 3 @COF-SA composite. Moreover, the (TiNbC/MnCO 3 @COF-SA) hydrogel was thoroughly characterized using a range of analytical techniques, such as FTIR, XPS, SEM, TEM, EDX, XRD, TGA, AFM, and zeta potential measurements. Photocatalytic degradation experiments were carried out to evaluate its performance in removing disinfection by-products (DBPs) from water, revealing efficient pollutant elimination mechanisms. Varied experimental parameters, including pH, initial concentration, reaction time, and temperature, were systematically explored to describe their influence on photocatalytic degradation capacities. Notably, the degradation efficiency of materials toward three DBP (2,4,6-triiodophenol (TIP), 2,4,6-Trichlorophenol (TCP) and 2,6-dichloro-4-nitrophenol (DCNP) were evaluated. Additionally, photocatalytic degradation was evaluated under different pH conditions (pH 4.0, 7.0, and 10.0). Under neutral conditions (pH 7.0) with an initial DBP concentration of 100   μg/L, the degradation efficiencies for TIP, TCP, and DCNP reached 77.0%, 81.3%, and 84.8%, respectively, within 60   min of UV irradiation. Moreover, compared to acidic or neutral environments, alkaline environments were identified as favorable to enhanced DBP degradation. The degradation rate within temperature was 86.0%, 93.0%, and 96.0%, respectively. In short, the TiNbC/MnCO 3 @COF-SA composite shows strong potential for efficient wastewater treatment and clean water recovery.