Developing adjustable micro- and mesopore structured carbon materials from wood via biotechnology for enhanced capacitive deionization

•Tunable pore structures in wood-derived carbon enhance CDI efficiency.•Fungal pretreatment yields nitrogen-doped carbon with superior porosity.•Innovative approach boosts desalination, outperforming conventional electrodes. Capacitive deionization (CDI) has attracted significant investigation interest for its potential in low-cost, efficient, and non-selective ion removal. However, achieving high performance in adsorption capacity and efficiency remains challenging, particularly with conventional biomass-derived electrodes. In this study, we developed adjustable, intricately porous, and hydrophilic wood-derived nanocarbon electrodes for electrochemical deionization. Our approach utilized biological pretreatment white-rot fungi, followed by chemical activation, effectively disrupting the rigid crystalline-amorphous structure of wood to create open micro-mesoporous networks. The resulting CDI carbon electrodes featured a predominance of micropores (especially below 0.8 nm) and a pronounced mesoporous arrangement, with a specific surface area of 1788 m2/g and 48 % meso-porosity. Additionally, this process enhanced surface oxidation and nitridation, resulting in surfaces rich in oxygen- and nitrogen-containing functional groups. These characteristics enable the electrodes to achieve a maximum adsorption capacity of 28.78 mg/g within 30 min, outperforming the performance of common biomass-derived electrodes. Moreover, the electrodes demonstrated excellent adsorption capacities for other contaminants, including 29.76 mg/g for NaF, 30.12 mg/g for Cd(NO3)2, and 27.24 mg/g for Pb(NO3)2. This study offers a cost-effective and viable alternative to current CDI electrodes, advancing the field by providing a viable solution to the limitations of existing technologies.