Investigation of Electrical and Electrochemical Properties of Ascorbic Acid-Treated SnO<sub>2</sub>/MXene Heterostructures for Hybrid Supercapacitors
Hina Mustafa, Aamir Rasheed, Sara Ajmal, Nasir Sarwar, Ushnah Falak, Seung Goo Lee, Abdul Sattar
Abstract
Recently, Ti 3 C 2 T x (MXene) and its heterostructures (HSs) with metal oxides have emerged as excellent materials for supercapacitors considering its distinctive electrochemical properties. However, environmental instability and poor interfacial interactions in two-dimensional (2D) Ti 3 C 2 T x (MXene) and its HSs with metal oxides (due to surface group repulsion) have been a great challenge. Moreover, restacking of MXene passivates the active sites of the electrode. Here, we presented a novel approach to synthesizing ascorbic acid-treated MXene/SnO 2 HS-based flexible electrodes for SCs. As-synthesized 3D SnO 2 nanoflowers (NFs) were treated with ascorbic acid to activate their surface and provide a linkage site for MXene sheets. SnO 2 NFs not only act as nanopillars between these layers but also maintain an appropriate space between the 2D layers and provide a 2D surface for charge storage. In conclusion, the self-assembly of these 2D–3D structures is retained, making it a more promising material for high-performance SC electrodes. The reported material not only presented an appreciable specific capacitance of 643 F/g but also demonstrated great electrochemical stability (only a 2% decrease) after 1000 cycles. In addition, the SnO 2 -anchored MXene showed great resistance against environmental humidity.