Fabrication of nanomagnetite/graphitic carbon nitride composite for adsorption and photo-Fenton decomposition of methylene blue dye

Abstract Pollution caused by synthetic dyes is an urgent issue, necessitating the development of highly effective and environmentally friendly solid adsorbents and catalysts. Herien, nanomagnetite/graphitic carbon nitride composite (NgCN) was developed for the adsorption and photo-Fenton breakdown of methylene blue. The formed NgCN composite has low band gap energy (2.14 eV), high surface area of 94.9 m 2 /g, various chemical surface functional groups, and a TEM average particle size of 10 nm. The adsorption and Fenton approach were studied under several application circumstances. The Langmuir maximum adsorption capacity was verified by NgCN (80.65 mg/g) at pH = 6, and the adsorption was well-applied by Langmuir, Temkin, and Freundlich, as adsorption isotherm models. The kinetic experiments proved the application of nonlinear PSO and Elovich models, and 6 h is the optimum adsorption equilibrium time. The degradation data from Fenton and photo-Fenton show that NgCN is more effective than nanomagnetite (Ng) and graphitic carbon nitride ( g -C 3 N 4 ). Methylene blue breakdown exhibits 100% using NgCN catalyst under UV light at 40 °C, at 40 min of the catalytic activity. Kinetic and thermodynamics of MB decomposition by photo-Fenton verified the PFO, nonspontaneous, and endothermic catalytic procedure. Throughout eight photo-Fenton cycles, the reusability of NgCN declined by only 4.0%. The NgCN demonstrated significant dye adsorption and decomposition efficacy at varying pollutant concentrations. The fabricated material is a promising solid adsorbent as well as a photo-Fenton catalyst for the removal of organic pollutants.