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Single‐Step Hydrothermal Synthesis of N, S‐Dual‐Doped Graphene Networks as Metal‐Free Efficient Electrocatalysts for Oxygen Reduction Reaction
Author(s) -
Lv Yang,
Wang Xianbao,
Mei Tao,
Li Jinhua,
Wang Jianying
Publication year - 2018
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201800098
Subject(s) - graphene , catalysis , oxide , heteroatom , materials science , electrochemistry , methanol , sulfur , hydrothermal circulation , chemical engineering , doping , inorganic chemistry , nanotechnology , electrode , chemistry , organic chemistry , metallurgy , ring (chemistry) , optoelectronics , engineering
Doping of heteroatoms and radicals is an important method to improve catalytic performances of graphene. However, typical heteroatom‐doped methods are mostly involved in gas phase deposition or high‐temperature annealing under specific gases, and need exceptional equipment and complicated technology. In this work, we explore a low temperature, thrifty, and ordinary one‐step hydrothermal approach to synthesize nitrogen‐sulfur dual doped reduced graphene oxide (N, S‐rGO) networks at low temperature, therein thiourea was used as both nitrogen (N) and sulfur (S) sources and a reducing agent to make graphene oxide (GO) reduced synchronously with N and S in situ doping into skeleton frame of GO. The synthesized N, S‐rGO has large N and S proportions (2.1 at% and 3.54 at%, respectively), and high‐grade sulfur‐containing types (mainly ‐C‐S‐C‐) and high relative percentage pyridinic‐N (44.6%) and graphitic‐N (33.9%). Many open edges and defects are attached on the surface of the N, S‐rGO, and it is beneficial to improve the electrocatalytic activity of oxygen reduction reaction (ORR). Electrochemical tests show that the N, S‐rGO has the outstanding electrical conductivity and predominant electrocatalytic activity for ORR. Its stability and methanol tolerance are greatly enhanced compared with commercial Pt/C catalyst. The low‐temperature one‐step method offers the probability for the preparation of N, S‐rGO in electronic devices and applications in electrode materials of fuel cells.