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Precious‐Metal‐Free Electrocatalysts for Activation of Hydrogen Evolution with Nonmetallic Electron Donor: Chemical Composition Controllable Phosphorous Doped Vanadium Carbide MXene
Author(s) -
Yoon Yeoheung,
Tiwari Anand P.,
Choi Min,
Novak Travis G.,
Song Wooseok,
Chang Hyunju,
Zyung Taehyoung,
Lee Sun Sook,
Jeon Seokwoo,
An KiSeok
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201903443
Subject(s) - overpotential , materials science , tafel equation , phosphide , mxenes , catalysis , carbide , oxide , gibbs free energy , doping , vanadium , hydrogen , inorganic chemistry , chemical engineering , chemistry , nanotechnology , metal , electrochemistry , thermodynamics , organic chemistry , metallurgy , electrode , optoelectronics , engineering , physics
The insufficient strategies to improve electronic transport, the poor intrinsic chemical activities, and limited active site densities are all factors inhibiting MXenes from their electrocatalytic applications in terms of hydrogen production. Herein, these limitations are overcome by tunable interfacial chemical doping with a nonmetallic electron donor, i.e., phosphorization through simple heat‐treatment with triphenyl phosphine (TPP) as a phosphorous source in 2D vanadium carbide MXene. Through this process, substitution, and/or doping of phosphorous occurs at the basal plane with controllable chemical compositions (3.83–4.84 at%). Density functional theory (DFT) calculations demonstrate that the PC bonding shows the lowest surface formation energy (Δ G Surf ) of 0.027 eV Å −2 and Gibbs free energy (Δ G H ) of –0.02 eV, whereas others such as P‐oxide and PV (phosphide) show highly positive Δ G H . The P3–V 2 CT x treated at 500 °C shows the highest concentration of PC bonds, and exhibits the lowest onset overpotential of –28 mV, Tafel slope of 74 mV dec −1 , and the smallest overpotential of ‐163 mV at 10 mA cm −2 in 0.5 m H 2 SO 4 . The first strategy for electrocatalytically accelerating hydrogen evolution activity of V 2 CT x MXene by simple interfacial doping will open the possibility of manipulating the catalytic performance of various MXenes.