title: Magnesiothermic synthesis of sulfur-doped graphene as an efficient metal-free electrocatalyst for oxygen reduction.
abstract: Efficient metal-free electrocatalysts for oxygen reduction reaction (ORR) are highly expected in future low-cost energy systems. We have successfully prepared crumpled, sheet-like, sulfur-doped graphene by magnesiothermic reduction of easily available, low-cost, nontoxic CO2 (in the form of Na2CO3) and Na2SO4 as the carbon and sulfur sources, respectively. At high temperature, Mg can reduce not only carbon in the oxidation state of +4 in CO3(2-) to form graphene, but also sulfur in SO4(2-) from its highest (+6) to lowest valence which was hybridized into the carbon sp(2) framework. Various characterization results show that sulfur-doped graphene with only few layers has an appropriate sulfur content, hierarchically robust porous structure, large surface area/pore volume, and highly graphitized textures. The S-doped graphene samples exhibit not only a high activity for ORR with a four-electron pathway, but also superior durability and tolerance to MeOH crossover to 40% Pt/C. This is mainly ascribed to the combination of sulfur-related active sites and hierarchical porous textures, facilitating fast diffusion of oxygen molecules and electrolyte to catalytic sites and release of products from the sites.
authors: 1] State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [2] Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [3] Shanghai Institute of Materials Genome, Shanghai, P. R. China.
authors: Jiacheng
authors: J
authors: Wang
authors: 1] State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [2] Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [3] Shanghai Institute of Materials Genome, Shanghai, P. R. China.
authors: Ruguang
authors: R
authors: Ma
authors: 1] State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [2] Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [3] Shanghai Institute of Materials Genome, Shanghai, P. R. China.
authors: Zhenzhen
authors: Z
authors: Zhou
authors: 1] State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [2] Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [3] Shanghai Institute of Materials Genome, Shanghai, P. R. China.
authors: Guanghui
authors: G
authors: Liu
authors: 1] State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [2] Innovation Center for Inorganic Materials Genomic Science, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, P. R. China [3] Shanghai Institute of Materials Genome, Shanghai, P. R. China.
authors: Qian
authors: Q
authors: Liu