Mechanochemical versus chemical routes for graphitic precursors and their performance in micropollutants removal in water

Sustainable and low-cost technologies for carbon-based nanomaterials are required for wastewater treatment. Two graphitic precursors (graphite flakes and graphite powder) were tested to synthesize graphene-related materials using mechanochemical treatment. For comparison, chemical graphite oxide (GO imp) was synthesized. The pristine and final products were characterized by SEM-EDX, particle size distribution, elemental analysis, surface area, DTA-TG and Raman spectra. Oxygen/carbon ratios of the mechanochemical and chemical routes were detected by EDX and confirmed using elemental analysis. The surface area increased from ~1 up to 666 and 328 m2 g−1 for graphite flakes and graphite powder at 24 h of mechanochemical treatment, respectively. However, the surface area for GO imp reached 157 m2 g−1. The removal of methylene blue, acid orange 7 and bisphenol A with the mechanochemical synthesized graphite oxides reached >93.8% at 30 min. The adsorption mechanism is mainly governed by π − π interactions and hydrogen bonding.