Nitrogen-Doped Hollow Mesoporous Carbon Spheres for Efficient Water Desalination by Capacitive Deionization

Abstract

Water desalination performance of capacitive deionization (CDI) largely depends on electrode materials properties. Rational design and regulation of the structure and composition of electrode materials to acquire high CDI performance is of great significance. Herein, nitrogen-doped hollow mesoporous carbon spheres (N-HMCSs) were investigated as electrode material for CDI application. To understand the effect of structure and composition on CDI performance, another two CDI electrode materials, i.e., hollow mesoporous carbon spheres (HMCSs) and solid mesoporous carbon spheres (SMCSs) were prepared for comparison. The obtained N-HMCSs possessed unique hollow cavity and excellent nitrogen doping property, resulting in fast ion diffusion, good charge transfers ability and fine wettability. Compared with HMCSs and SMCSs electrodes, N-HMCSs electrode exhibited an improved electrosorption capacity and rate, demonstrating the dependence of CDI performance on the synergistic effect of hollow structure and nitrogen doping property. N-HMCSs electrode also present excellent cycle stability over 20 adsorption–desorption cycles. These results indicate the promising prospect of N-HMCSs for CDI application.

One‐Step Activation of Anode Materials from Spent Lithium‐Ion Batteries as High‐Performance Electrodes for Capacitive Deionization

“…Clearly, the values of I D /I G for AMCS2‐1, AMCS3‐1 and AMCS4‐1 all increase compared with MMCS, which experience a KOH activation process. It is pointed that the KOH activation process promotes defective or disordered carbon matrix degree, [13] in agreement with the SEM and XRD results. Importantly, the disordered structure of carbon spheres is beneficial for charge accumulation and transportation in the CDI process [14]…”

“…The reason above can be confirmed by previous desalination experiments performed by our group [21] . However, the charge efficiency of AMCS3‐1 remains above 0.515 at a voltage of 1.2 V, which is much greater than other CDI‐based carbon materials reported in many studies (Table S6) [13,22] …”

Oxygen Vacancy–Rich In‐Doped CoO/CoP Heterostructure as an Effective Air Cathode for Rechargeable Zn–Air Batteries

“…Owing to high oxygen vacancies, the In‐CoO/CoP FNS electrode displays a significant improvement of wettability and hydrophilicity, as verified by the dynamic water contact angle measurements ( Figure a). It is observed that the In‐CoO/CoP FNS electrode shows a lower contact angle of 8.0° than that of In‐CoO/CoP NS electrode (10.4°).…”

Metallic Co9S8 Coupled Hollow N‐Doped Carbon Sphere with Synergistic Interface Structure for Efficient Electricity Generation in Microbial Fuel Cells

“…Deconvolution of the N 1s signal of Co 9 S 8 /NHCS (Figure S5b) yielded two peaks due to pyridinic N at 398.3 eV and quaternary N at 400.8 eV . The above results implied the nitrogen successfully doped into carbon shell of in NHCS that would possess advantaged charge transfer ability . It should be noticed that the active sites in NHCS were C atoms adjacent to pyridinic N because of the electron accepting ability, so that the positive‐charge C atoms can greatly facilitate the ORR process .…”