Sustainable Ball Milling-Assisted Synthesis of Bread Waste-Derived Highly Porous Carbons for Adsorption-Based Applications

A facile synthesis was used for the preparation of highly porous carbons from bread waste. This synthesis relied on the fast ball milling of only two reagents, dry bread, and a mild activation agent, followed by direct thermal treatment at 800°C, afforded carbons with high specific surface areas up to 2400 m2·g-1, and a large pore volume up to 1.56 cm3·g-1. This seems to be the first attempt to employ ball milling for the synthesis of sustainable bread-derived highly porous carbons. Effective activation was achieved thanks to homogeneous distribution of the activating agent throughout the precursor, ensured by mechanochemical treatment. These carbons adsorbed a high amount of carbon dioxide at 0°C and 1 bar, up to 6.7 mmol·g-1. Moreover, cyclic stability, CO2/N2 selectivity at 0°C, and benzene adsorption-desorption isotherms at 20°C were determined for the selected samples. High porosity in carbons is essential for adsorption and catalysis-related applications. Additionally, the proposed strategy provides a solution for cost-effective and feasible food waste management.