The novel Auricularia-like MoS2 as binder-free electrodes for enhanced capacitive deionization

Abstract

Molybdenum disulfide (MoS₂) has been proven to be an effective and promising electrode material for capacitive deionization (CDI) due to its unique architectures and excellent electrochemical activity. However, MoS₂-based electrodes still suffer from the high contact electrical resistance between MoS₂ and the current collectors because of the necessity of adding binder during their fabrication. In this work, a flexible MoS₂-based electrode with no binders was successfully fabricated. It was found that the frameworks of stainless-steel mesh with surface treatment could serve as an ideal substrate to provide plenty of active nucleation sites for the growth of MoS₂. Consequently, a novel morphology of MoS₂ with Auricularia-like architectures was produced. Based on electrochemical impedance spectroscopy (EIS), the charge transfer resistance was reduced to nearly zero after the treatment, highly increasing the transportation of charges inside the electrodes compared to the common MoS₂-based electrodes. As a result, the binder-free MoS₂-based electrodes demonstrated a superior desalination performance of 28.76 mg g^-1 (1.2 V) for NaCl solution, which was superior to that of common MoS₂-based and many other advanced materials-based electrodes. The novel MoS₂-based electrode not only facilitates the utilization of MoS₂ in CDI but also paves the way for its application in other electrochemical domains.