In-situ hydrothermal synthesis of MnO2/NiO@Ni hetero structure electrode for hydrogen evolution reaction and high energy asymmetric supercapacitor applications. (May 2016)

• Record Type: Journal Article
• Authors: Saha, Sanjit; Chhetri, Suman; Khanra, Partha; Samanta, Pranab; Koo, Hyeyoung; Murmu, Naresh Chandra; Kuila, Tapas
• Is Part Of: Journal of energy storage. Volume 6(2016)
• Page Start: 22
• Page End: 31
• Publication Date: 2016-05
• Subjects: Multi-metal oxide -- Binder free electrode -- Hydrogen evalution reaction -- Thermaly reduced graphene oxide -- Asymmetric device -- Energy density; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2016.02.007
• Languages: English
• ISSNs: 2352-152X

Abstract

Graphical abstract: Highlights: Binder free MnO2 /NiO@Nielectrode was developed. MnO2 /NiO@Ni shows superior HER activity with low onset potential of 0.17 V. MnO2 /NiO@Ni was used as the positive electrode of supercapacitor. ASC device shows high energy density of 59.5 Wh kg −1 . ASC remains 75% stable after 10, 000 CD cycles. Abstract: In-situ deposition of MnO2 /NiO hetero structure on Ni-foam has been carried out through simple one-step hydrothermal reaction. The in-situ deposited multi-metal oxide shows extraordinary electrocatalytic activity in hydrogen evolution reaction with a small Tafel slope of 38 mV per decade and very low onset potential of 0.17 V. An electrolyser has been fabricated with MnO2 /NiO deposited Ni-foam which effectively achieves a current density of ∼24 mA cm −2 at an applied voltage of ∼1.57 V. Furthermore, the metal oxide deposited on Ni-foam is directly used as the supercapacitor electrode which shows good rate capability as positive electrode materials. An asymmetric capacitor (ASC) has been assembled by using the MnO2 /NiO deposited Ni-foam as positive electrode and thermally reduced graphene oxide as negative electrode. The assembled ASC has a large specific capacitance of 218 F g −1 at a current density of 3 A g −1 and can deliver high energy and power density of 59.5 Wh kg −1 and 25, 350 W kg −1, respectively. The ASC shows very good electrochemical stability throughout 10, 000 charge–discharge cycles along with the capability to work in the high frequency range.