title: Direct Chemical Synthesis of MnO2 Nanowhiskers on Transition-Metal Carbide Surfaces for Supercapacitor Applications.
abstract: Transition-metal carbides (MXenes) are an emerging class of two-dimensional materials with promising electrochemical energy storage performance. Herein, for the first time, by direct chemical synthesis, nanocrystalline ε-MnO2 whiskers were formed on MXene nanosheet surfaces (ε-MnO2/Ti2CTx and ε-MnO2/Ti3C2Tx) to make nanocomposite electrodes for aqueous pseudocapacitors. The ε-MnO2 nanowhiskers increase the surface area of the composite electrode and enhance the specific capacitance by nearly 3 orders of magnitude compared to that of pure MXene-based symmetric supercapacitors. Combined with enhanced pseudocapacitance, the fabricated ε-MnO2/MXene supercapacitors exhibited excellent cycling stability with ∼88% of the initial specific capacitance retained after 10000 cycles which is much higher than pure ε-MnO2-based supercapacitors (∼74%). The proposed electrode structure capitalizes on the high specific capacitance of MnO2 and the ability of MXenes to improve conductivity and cycling stability.
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.|Chemical Sciences and Technology Division, CSIR- National Institute of Interdisciplinary Sciences and Technology (CSIR-NIIST) , Thiruvananthapuram, Kerala 695019, India.
authors.forename: Raghavan Baby
authors.initials: RB
authors.lastname: Rakhi
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.
authors.forename: Bilal
authors.initials: B
authors.lastname: Ahmed
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.
authors.forename: Dalaver
authors.initials: D
authors.lastname: Anjum
authors.affiliation: Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900, Saudi Arabia.
authors.forename: Husam N
authors.initials: HN
authors.lastname: Alshareef
keywords: MXene; cycle life; specific capacitance; symmetric supercapacitor; ε-MnO2/MXene