Cross-Linked Fungal Biotemplate Enables Highly Efficient Nanomaterial Recovery and Reutilization as Porous Carbon

Waste nanomaterials pose environmental and human health concerns and they need to be urgently and efficiently managed. In this study, a fungal biotemplate was used to accumulate and recover nano-Fe2O3 materials from an aqueous solution. Then, recovered nano-Fe2O3 materials were activated to form a high-performance magnetic porous carbon composite (FePC) for energy storage and organic pollutant removal. The results indicate that high concentrations (500 mg/L) of 50 nm Fe2O3 particles can be completely recovered using a cross-linked Neurospora crassa fungus (NC), primarily because of its encapsulation function. In addition, the surface area, degree of graphitization, and heteroatom content of the FePC materials can be boosted by the catalytic effects of the incorporated Fe atoms. The developed FePC materials exhibit potential as high electrical double-layer capacitors as well as strong retention capabilities, excellent stability, and efficient adsorption of triclosan (TCS, ~526 mg/g). Additionally, these FePC materials exhibit superior capacities for energy storage and pollutant reduction compared to commercial and reported carbon materials. These results reveal a sustainable route for the recovery and reutilization of nanomaterials.