Enhanced Capacitive Desalination Performance of Porous Carbon Spheres@MnO2 Composite

A porous carbon spheres@MnO2 composite is prepared and used as the electrosorption electrode. The MnO2 nanoparticles are evenly distributed on the porous carbon spheres. The as-prepared composite possesses high specific surface area of 258.6 m2·g -1. Its electrochemical evaluations confirm that the composite has high specific capacitance of 175 Fog-1 at a current density of 1 A·g -1 in 0.5 mol·L-1 NaC1 aqueous solution, and shows good conductivity and excellent cycling performance. Electrosorption capacity for the porous carbon spheres@MnO2 composite is 6.28 mg·g-1. Moreover, the composite electrode exhibits excellent recyclability with an efficient regeneration process.

Integration of pore structure modulation and B,N co-doping for enhanced capacitance deionization of biomass-derived carbon

Biomass-derived carbon has demonstrated great potentials as advanced electrode for capacitive deionization(CDI),owing to good electroconductivity,easy availability,intrinsic pores/channels.However,conventional simple pyrolysis of biomass always generates inadequate porosity with limited surface area.Moreover,biomass-derived carbon also suffers from poor wettability and single physical adsorption of ions,resulting in limited desalination performance.Herein,pore structure optimization and element co-doping are integrated on banana peels(BP)-derived carbon to construct hierarchically porous and B,N co-doped carbon with large ions-accessible surface area.A unique expansionactivation(EA)strategy is proposed to modulate the porosity and specific surface area of carbon.Furthermore,B,N co-doping could increase the ions-accessible sites with improved hydrophilicity,and promote ions adsorption.Benefitting from the synergistic effect of hierarchical porosity and B,N co-doping,the resultant electrode manifest enhanced CDI performance for NaCl with large desalination capacity(29.5 mg g^(-1)),high salt adsorption rate(6.2 mg g^(-1)min^(-1)),and versatile adsorption ability for other salts.Density functional theory reveals the enhanced deionization mechanism by pore and B,N co-doping.This work proposes a facile EA strategy for pore structure modulation of biomass-derived carbon,and demonstrates great potentials of integrating pore and heteroatoms-doping on constructing high-performance CDI electrode.

A novel flow electrode capacitive deionization device with spindle-shaped desalting chamber

Flow-electrode capacitive deionization(FCDI)is an innovative technology in which an intermediate chamber plays an important role in the desalination process.However,relatively few studies have been conducted on the structures of these intermediate chambers.In this study,we propose a novel flow-electrode capacitive deionization device with a spindle-shaped inlet chamber(S-FCDI).The desalination rate of the S-FCDI under optimal operating conditions was 36%higher than that of the FCDI device with a conventional rectangular chamber(R-FCDI).The spindle-shaped chamber transferred 1.2μmol more ions than the rectangular chamber,based on energy per joule.Additionally,we performed a detailed analysis of different inlet chamber shapes using computational fluid dynamics software.We concluded that S-FCDI has a relatively low flow resistance and almost no stagnation zone.This provides unique insights into the development of intermediate chambers.This study may contribute to the improvement of the desalination performance in industrial applications of FCDI.