Integrating energy-environmental functions into multifaceted lignocellulose valorization: high-performance supercapacitors and antibiotic decomposition

Abstract

Engineered lignocellulose valorization enables the formation of superior energy and environmental materials which are developed to achieve the aim of sustainable carbon-neutral technologies. In this work, sequential manufacture under the trigger of hydrothermal fractionation is proposed for the “two-in-one” valorization of wheat straw into highly dispersed Fe, N-codoped carbon spheres (Fe–N–C) and Co nanoclusters anchored on biochar (Co–N–C) via using synchronous pyrolysis/activation. Taking advantage of the ordered ion-diffusion shortcut, suitable geometric/nanosized porous structure, ultrahigh surface area, well-developed packing architecture, and multiple redox possibilities (i.e., Fe species and N functional groups), the durable, conductive Fe–N–C microspheres can function as supercapacitor electrodes, exhibiting superior specific capacitance, rate-performance, and long-cycling lifespan. Benefitting from well-exposed Co nanoclusters and N coordination, the recyclable Co–N–C catalysts enabling efficient persulfate activation are conducive to expediting tetracycline removal with a working pH from 3 to 9, and a concomitant mechanism involving reactive oxygen species and interface electron shuttling is revealed via radical trapping, direct charge-transfer, and theoretical simulation. Hence this work provides multifaceted insights into a coupling strategy for lignocellulose conversion that involves matching the brand-new “biomass–energy–water” interplay with improved biorefining value.