Three-dimensional polyaniline architecture enabled by hydroxyl-terminated Ti3C2Tx MXene for high-performance supercapacitor electrodes. (30th September 2021)

• Record Type: Journal Article
• Authors: Wang, Lin; Tan, Yu; Yu, Zhifeng; Tian, Hua; Lai, Yuannan; He, Yunyi; Xiang, Hanqing; Wang, Jianwei; Zhao, Wenjun; Zhang, Lin
• Is Part Of: Materials chemistry frontiers. Volume 5:Number 21(2021)
• Page Start: 7883
• Page End: 7891
• Publication Date: 2021-09-30
• Subjects: Materials science -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1039/d1qm01059j
• Languages: English
• ISSNs: 2052-1529

Abstract

Abstract : Hydroxyl-terminated Ti3 C2 T x MXene obtained by a step-by-step removal of the intermediate element from MAX phases can effectively improve the electrochemical performance of PANI for supercapacitors. Abstract : Termination-mediated surface functionalization of Ti3 C2 T x MXene is greatly explored for extensive applications in the electrochemical energy storage. Herein, the predominance of surface-terminated hydroxyl groups on Ti3 C2 T x MXene is realized by a step-by-step removal of the intermediate element from MAX phases. In a sequence of NaOH and HF-etching processes, the former facilitates the coupling of hydroxyl groups with native defects of etched Ti3 AlC2 T x, dependending on selectively extracting the partial Al element. The latter allows the dissolution of the residual Al element towards the chemical exfoliation of Ti3 C2 T x MXene. Importantly, the negatively charged surface of hydroxyl-terminated Ti3 C2 T x MXene tends to attract emeraldine-based PANI nanosheets dispersed in N -methyl pyrrolidone, so as to break intrinsic hydrogen bonds between emeraldine-based PANI and N -methyl pyrrolidone. The reinforcement of the binding interaction in PANI/hydroxyl-terminated Ti3 C2 T x composites is beneficial for the uniform coating of PANI on the layered configuration of hydroxyl-terminated Ti3 C2 T x to form the three-dimensional architecture in favor of exposing the electrolyte-accessible surface of electrodes. The result shows that PANI/hydroxyl-terminated Ti3 C2 T x composites achieve a specific capacitance of 464 F g −1 at a current density of 1 A g −1 in comparison with those of 307 F g −1 for emeraldine-based PANI and 348 F g −1 for PANI/pristine Ti3 C2 T x composites. After 4000 cycles, PANI/hydroxyl-terminated Ti3 C2 T x composites also exhibit excellent cycling stability with high capacitance retention of 86% at a current density of 10 A g −1, suggesting that the surface functionalization of MXene is an effective route to improve the electrochemical performance of MXene-based composites.