Vol.:(0123456789) 1 3 Topics in Catalysis https://doi.org/10.1007/s11244-021-01472-7 ORIGINAL PAPER Hydrothermal Synthesis of Flower Like MnSe 2 @MoSe 2 Electrode for Supercapacitor Applications M. Sangeetha Vidhya 1  · R. Yuvakkumar 1  · P. Senthil Kumar 2  · G. Ravi 1  · D. Velauthapillai 3 Accepted: 7 July 2021 © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2021 Abstract Active electrodes of transition metal selenides attract extensive consideration in energy storage application because of its improved electrochemical performances. In this study, evolution of fower like MnSe 2 @MoSe 2 was subsequently synthesized through one pot hydrothermal route. Growth of combined composite exposed fowerlike morphology with looser corrugated nanospikes increases surface area for redox reaction which reduces ionic difusion pathway and improves supercapacitor performance in three-cell confgurations. The best performed (MMS-3) electrode exhibited 719 Fg −1 specifc capacitance and retained 99.78% capacity retention over 2000 cycles. Furthermore, as an asymmetric MnSe 2 @MoSe 2 //AC device delivered signifcant 75 Whkg −1 energy density at 747 Wkg −1 power density. Besides, asymmetric (MMS-3)//AC device maintained 99.16% capacity retention after constant 2000 charge discharge cycles. In a small-scale practical demonstration, MnSe 2 @ MoSe 2 //AC device illuminated red LED and displayed improved electrochemical performance. Hence, both Mn (manganese) and Mo (molybdenum) mutual role promotes more afuent redox chemistry, which is benefcial for higher electrochemical activity. Thereby, Se provided greater number of electroactive sites that can aid maximum utilization of electrolyte ions. Keywords Supercapacitor · Electrochemical performance · Stability · Energy storage and conversion 1 Introduction Currently, environment and energy paved more attention to stimulate the research towards the electrochemical storage and conversion for a new sort of energy supply [1, 2]. Conse- quently, the supercapacitors (SC) have gained importance as high efciency storage devices because of their unique prop- erties like elevated charge discharge mechanism [3–5], nota- ble power density [6–8], stable cycle life, and environmental protection than the batteries when compared with the tradi- tional capacitors [9, 10]. Based on charge storage and deliv- ery, in electrical double-layered capacitors (EDLC) charge is being stored electrostatically [11, 12] and in pseudoca- pacitors, mainly of faradaic origin store energy at electrode surface or in shallow depth of the electrode material [13]. In general, various carbonaceous material and their deriva- tives served as the electrode material for EDLC and whereas metal oxides, selenides and polymers are explored as the active electrode for pseudocapacitors. The high performance of the SCs is achieved by opting reasonable electrode with the aptly preferred electrolyte. Recently, metal selenides signifcantly aforded as an efcient electrocatalyst for elec- trochemical performances [14]. Transition metal selenides (TMS) is studied for several electrochemical areas owing to extraordinary physical, chemical and electrical properties. The main advantage of selecting two diferent selenide mate- rials is that selenium electronegativity is than low oxides and sulfurs. Therefore, MnMo based selenide could provide rich electroactive sites for improving specifc capacitance and outstanding electrochemical stability. Therefore, the synthesized material will enhance electrochemical activity. The unique conductivity, rate performance, large volume variation and capable synergetic efect sandwiched between transition metal and selenides enhanced the electrochemical energy storage activity. Moreover, the high metallic nature * R. Yuvakkumar yuvakkumarr@alagappauniversity.ac.in * P. Senthil Kumar senthilkumarp@ssn.edu.in 1 Department of Physics, Alagappa University, Tamil Nadu, Karaikudi 630 003, India 2 Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai 603110, India 3 Faculty of Engineering and Science, Western Norway University of Applied Sciences, 5063 Bergen, Norway