Synthesis and electrochemical properties of 2D molybdenum vanadium carbides – solid solution MXenes. Issue 18 (27th April 2020)

• Record Type: Journal Article
• Authors: Pinto, David; Anasori, Babak; Avireddy, Hemesh; Shuck, Christopher E.; Hantanasirisakul, Kanit; Deysher, Grayson; Morante, Joan Ramon; Porzio, William; Alshareef, Husam N.; Gogotsi, Yury
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 18(2020)
• Page Start: 8957
• Page End: 8968
• Publication Date: 2020-04-27
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta01798a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : MXenes demonstrate high performance in energy storage. We report the synthesis and electrochemical characterization of a novel MXene, Mo x V4− x C3 . Abstract : MXenes have demonstrated high performance as negative electrodes in supercapacitors with aqueous electrolytes due to their high redox capacitance. However, oxidation limits their use under positive potential, requiring asymmetric devices with positive electrodes made of other materials which are usually less capacitive compared to MXenes and therefore limit the device performances. Here, we report the synthesis of two-dimensional molybdenum vanadium carbides (Mo x V4− x C3 ), previously unexplored double transition metal MXenes, by selective etching of aluminum from Mo x V4− x AlC3 MAX phase precursors. Unlike the ordered double transition metal MXenes reported previously, Mo x V4− x C3 exhibits a Mo–V solid solution in the transition metal layers. We have synthesized and characterized four different compositions of Mo x V4− x C3 with x = 1, 1.5, 2, and 2.7. We showed that by changing the Mo : V ratio, the surface terminations (O : F ratio), and electrical and electrochemical properties of the resulting MXenes can be tuned. The Mo2.7 V1.3 C3 composition showed a remarkable volumetric capacitance (up to 860 F cm −3 ) and high electrical conductivity (830 S cm −1 ) at room temperature. Moreover, these solid solution MXenes have demonstrated the ability to operate in a wider range of positive potentials compared to other MXenes. Following this discovery, we coupled a Mo2.7 V1.3 C3 positive electrode with a well-studied Ti3 C2 MXene negative electrode to create an all-MXene supercapacitor, as a proof of concept.