Microbial-assisted upcycling of agricultural waste into dual-functional porous carbon for synergistic tetracycline decontamination and sustainable energy storage

Abstract

Converting agricultural waste into high-value materials is a promising strategy for concurrent environmental remediation and energy storage. Herein, we report a microbial-assisted route to convert soybean straw into hierarchical porous carbon (designated M800-Zn, where M = Myrothecium verrucaria，800 for 800 ℃ Zn-dual-salt activation). Starting from the raw biochar (SSC, 7.66 m² g⁻¹, 0.1289 mg g⁻¹ TC uptake), fungal pre-treatment followed by dual-salt activation boosts the BET area 317-fold to 2433.97 m² g⁻¹ and the tetracycline adsorption capacity 1934-fold to 249.37 mg g⁻¹ (pH 7), surpassing most reported carbons. When assembled into a symmetric supercapacitor, M800-Zn delivered 254.5 F g⁻¹ at 0.5 A g⁻¹ and retained 93.75 % capacitance after 5000 cycles at 2 A g⁻¹. This low-energy, 800 ℃ process (about 100 ℃ lower than conventional activation) thus provides a circular-economy-compatible material that simultaneously purifies antibiotic-contaminated water and sustains high-power energy storage.