title: The role of terminations and coordination atoms on the pseudocapacitance of titanium carbonitride monolayers.
abstract: Nowadays, MXenes have received extensive concern as a prominent electrode material of electrochemical capacitors. As two important factors to the capacitance, the influence of the intrinsical terminations (F, O and OH) and coordination atoms (C and N) is investigated using first-principles calculations. According to the density of states aligned with the standard hydrogen electrode, it turns out that a Ti3CNO2 monolayer is proven to show an obvious pseudocapacitive behavior, while the bare, F and OH terminated Ti3CN monolayers may only present electrochemical double layer characters in an aqueous electrolyte. Moreover, the illustration of molecular orbitals over the Fermi level are mainly contributed by the d-orbitals of Ti atoms coordinated with O and N atoms, indicating that the redox pseudocapacitance of the Ti3CNO2 monolayer is promoted by the coordination N atoms. Then the superiority of N bonded Ti atoms in accepting charges can be visualized through the charge population. Further, the larger ratio of C/N in the coordination environment of Ti atoms indicates that more electrons can be stored. Our investigation can give an instructional advice in the MXenes-electrode production.
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Wenqiang
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Chuan
authors.initials: C
authors.lastname: Cheng
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Peilin
authors.initials: P
authors.lastname: Fang
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Tang
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Jindou
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Guoming
authors.initials: G
authors.lastname: Huang
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Cong
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Bao
authors.initials: B
authors.lastname: Zhang
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ji
authors.affiliation: School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, People's Republic of China. hustjx@mail.hust.edu.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Miao