Galvanic exchange at layered doubled hydroxide/N-doped graphene as an in-situ method to fabricate powerful electrocatalysts for hydrogen evolution reaction

摘要

Introducing a novel strategy for growing dispersed metal nanoparticles at reduced graphene oxide (rGO) and nitrogen-doped GO (rNGO), this work aimed to design Pt-free electrocatalysts for water splitting. For this purpose, gold nanoparticles were fabricated by the in-situ galvanic exchange of layered double hydroxide (LDH) metals on rGO and rNGO. The significant roles of the galvanic exchange method, LaNi-LDH, and the Au nanoparticles synthesized on the rGO/rNGO-LaNi-LDH surface (Au(@)GO/rNGO-LaNiLDH) were investigated via a variety of methods and certain novel properties such as nitrogen-metal bridge bonds between the metal component of (AuLDH)-L-@ and the nitrogen component of rNGO were established, which indicated the semi-nanorod morphology of the.Au(@)rGO/rNGO-LaNi-LDH thus produced. Electrochemical studies were used to reveal an onset potential of only -80 mV vs. RHE at an exchange current density of about 10 mA cm(-2) with a small Tafel slope of 60 mV dec(-1) for the hydrogen generation reaction in a 0.5 mol L-1 H2SO4 solution. The isolated island architecture of rNGO/LaNi-LDH and rNGO/(AuLaNi)-La-@-LDH were found to promise rich and active sites to be exposed, which allow for the effective interaction of the reactants (e.g., protons) with these active sites. (C) 2016 Elsevier Ltd. All rights reserved.