Despite the remarkable electronic and mechanical properties of graphene, improving the catalytic activity of the atomically flat, inert, and stable carbon network remains a challenging issue in both fundamental and application studies. In particular, the adsorption of most molecules and ions, including hydrogen (H2 or H+), on graphene is not favorable, underlining the challenge for an efficient electrochemical catalytic reaction on graphene. Various defects, edges, and functionalization have been suggested to resolve the catalytic issue in graphene, but cost-effectiveness and active catalysis with graphene have not been achieved yet. Here, we introduce dynamic stacking of reduced graphene oxide (rGO) with spontaneously generated hydrogen bubbles to form an efficient electrochemical catalyst with a graphene derivative; the in operando stacking of rGO, without using a high-temperature-based heteroatom doping process or plasma treatment, creates a large catalytic surface area with optimized edges and acidic groups in the rGO. Thus, the uniquely formed stable carbon network achieves active hydrogen evolution with a Tafel slope of 39 mV·dec-1 and a double layer capacitance of 12.41 mF·cm-2, which breaks the conventional limit of graphene-based catalysis, suggesting a promising strategy for metal-free catalyst engineering and hydrogen production.
Bibliographical noteFunding Information:
This work is supported by the National Research Foundation of Korea (NRF) under Grant No. NRF-2017R1A2B2008366. S. Cho was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning (2017R1A2B4010423). S.H. Oh was supported by Creative Materials Discoverty Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (NRF-2019M3D1A1078296). H. Shin was supported by NRF-2019R1A2C3009157.
Copyright © 2019 American Chemical Society.
All Science Journal Classification (ASJC) codes
- Materials Science(all)