Enhanced capacitive deionization of defect-containing MoS2/graphene composites through introducing appropriate MoS2 defect

Abstract

Abstract Defect-containing MoS2/ reduced graphene oxide (rGO) composites were moderately prepared via chemical etching. The effects of MoS2 defect on the structure, electrochemical and desalination performance of the defect-containing MoS2/rGO composites were comparatively researched. The results showed that the defect-containing MoS2/rGO composite chemical etched with 5.0 g NaBH4 (dMSG-5) exhibited the advantages of the fewest amount of (002) interplanar layers, the smallest water contact angle and zeta potential, and the most amount of exposed edge sites. etc, which endowed it with the largest specific capacity (305.6 F/g at 1.0 A/g), the lowest interfacial charge transfer resistance and the best CDI performance with the biggest desalination capacity of 25.47 mg/g at the voltage of 0.8 V in 200 mg/L NaCl solution. The results suggested that appropriate MoS2 defect indeed could enhance the electrochemical and desalination performance of dMSG-5 via providing more adsorption sites for Na+ insertion/extraction and ion diffusion channels, and improving the ion accessibility and transport efficiency. Those pave the way for construction of other high-performance electrode materials and making dMSG-5 attractive to the electrode of CDI device.