Eco-friendly Fenton reagent-based negative ζ potential engineering of porous carbon materials and their applications on the effective removal of methylene blue and SARS-CoV-2 virus by enhanced electrostatic interaction†

Various pollutants in wastewater that are produced from industrial and domestic processes are causing huge threats to human health and environmental safety. Novel porous carbon materials with specially designed surface physiochemical characteristics and pore structures are considered one of the most potential candidates for the highly efficient removal of these pollutants via adsorption. In particular, they have the inherent characteristic of being positively charged towards cationic dyes and SARS-CoV-2 virus with the unique spike protein. Based on this, in this work, we proposed and developed a new strategy for surface-negative ζ potential engineering of porous carbon materials using Fenton reagent, which is a mild, eco-friendly but potent free radical provider. After the pretreatment with Fenton reagent, the amount of oxygen-containing functional groups increased considerably, followed by a distinct decrease in the ζ potential for the porous carbon materials, which, in turn, enabled a relatively higher binding force between the adsorbent and target adsorbate, resulting in the enhanced performance of porous carbon materials in the removal of methylene blue (585.1 mg g⁻¹) and SARS-CoV-2 virus-like-particles (98.61%, 50 g L⁻¹). Thus, this work not only highlights porous carbon materials as promising candidates for the removal of cationic dyes and viruses but also provides a universal strategy for producing negatively charged porous carbon materials with high feasibility and sustainability.