Carbon coated nickel - Nickel oxide composites as a highly efficient catalyst for hydrogen evolution reaction in acid medium

摘要

Carbon coated nickel - nickel oxide composites (Ni/NiO@C/GR-t-w) was synthesized from the direct carbonization of the composites composed of Ni-MOF-74 and graphene oxide (GO). Due to the synergetic effects of Ni, NiO and graphene, Ni/NiO@C/GR-t-w all exhibited the electrocatalytic performance to HER in acidic medium. When the GO content was 8% and the carbonization temperature was 900 degrees C, the composites (Ni/NiO@C/GR-900-8) showed the best electrocatalytic properties with an lower over-potential of 108mV (vs. RHE) at 10 mA cm(-2), a smaller Tafel slope of 44 mV dec(-1) and a good stability in a 0.5 M H2SO4 solution. The excellent electrocatalytic performance enabled Ni/NiO@C/GR composites to be a favorable HER catalyst to replace the expensive Pt-based materials in the applications of the hydrogen production. (C) 2018 Elsevier Ltd. All rights reserved.