Synergetic Nitrogen‐Rich Nanocarbon Decoration and Metal Intercalation Enabled Low‐Crystalline V3O7 Hybrids for Boosting Capacitive Sodium Capture

Abstract

AbstractFaradaic capacitive deionization (FCDI) with attractive ion‐capture capacity, outstanding durability, and potential compatibility in high‐salinity water has been recognized as the robust alternative to address the alarming freshwater scarcity. The further innovation of boosting electrode materials is the indispensable requisite for highly efficient FCDI application. Herein, a low‐crystalline nitrogen‐doped carbon quantum dots modified Mg2+‐pillar preintercalated V3O7 (i.e., NCQDs/Mg‐V3O7) heterostructure is assembled via an ingenious one‐spot hydrothermal avenue, and is investigated as the advanced FCDI electrode for desalination application. Taking advantages of the synergic effect of unique microstructure, improved electronic conductivity, and exceptional structural durability, the NCQDs/Mg‐V3O7 electrode delivers an admirable gravimetric adsorption capacity of 54.32 mg g−1 in a NaCl solution of 1500 mg L−1 and attractive cyclic durability. Further, density functional theory calculations verify the intense interface electron coupling interaction between tri‐components, enabling the significantly promoting Na+ capture capability. The synergy removal mechanism is clarified by ex‐situ X‐ray photoelectron spectroscopy and in‐situ Raman tests. Additionally, the average removal efficiency of hybrid electrode attains 93.75% in the simulated wastewater comprising the NaCl of 50 mg L−1 and diverse metal nitrates from 10 to 100 mg L−1 for each, certifying the great prospects for practical wastewater treatment.