Reduction of Graphene Oxide by Hydrogen Sulfide: A Promising Strategy for Pollutant Control and as an Electrode for Li-S Batteries

DOI: 10.1002/aenm.201301565 The increasing demand for environmentally friendly industries and effective pollution control has attracted great attention from both academic and industrial organizations for the development of new processes and novel materials. As a major air pollutant, hydrogen sulfi de (H 2 S), originating from various sources (natural gas processing, the refi ning and consumption of fossil fuel, etc.) must urgently be removed and reused due to its high toxicity towards the environment (acid rain) and living organisms. [ 1 ] Great efforts have been made to explore the effective removal of H 2 S and in most cases transitionmetal oxides and mixed oxides are used as adsorbents and/or catalysts for the oxidation of H 2 S, whereas others use zeolite, activated carbon (AC), and carbon nanotubes (CNTs) as adsorbents. [ 2,3 ] Carbon materials have appealing properties as adsorbents or catalyst supports for the removal of H 2 S. For instance, AC or CNTs have been widely used as supports of catalysts (ZnO, NiS 2 , etc.) for the catalytic oxidation of H 2 S. [ 3 ] Nevertheless, the regeneration and full utilization of the H 2 S and the development of high-performance adsorbents are still hard to realize. Thus, it is necessary to develop an appropriate approach to eliminate and recycle H 2 S to realize its regeneration and environmental protection. As a fascinating carbon material, graphene possesses excellent electrical, thermal, and mechanical properties due to its unique 2D structure, making it versatile in fundamental science and various applications, such as energy storage, sensors, adsorption, etc. [ 4 ] Due to its large and fully accessible surface and excellent conductivity, the use of graphene in the removal of H 2 S has been examined both experimentally and theoretically. [ 1a, 2, 5 ] Density functional theory (DFT) studies show that H 2 S molecules are physisorbed only on the surface of graphene, thus, in most cases, graphene has a low catalytic activity for H 2 S oxidation and also a low adsorption capacity. Graphene oxide (GO), the most important derivative of graphene, is decorated by abundant oxygen-containing groups on the graphene layer, and these help improve the reactivity and processability due to their hydrophilic nature. Although GO suffers from poor conductivity due to the destruction of the continuous sp 2