S-doped carbon materials: Synthesis, properties and applications

Carbon element is a widely distributed element in nature, and carbon nanomaterials have been widely used in the fields of energy storage, CO2 capture and H2 storage, high capacity adsorption of specific pollutants and sensors. In order to meet the more advanced applications of carbon nanomaterials, heteroatom doping of carbon materials has attracted much attention in recent years. Among the several usual elements for doping, sulfur atoms have many attractive characteristics, such as, large atomic radius, small electronegativity, many electrons and various covalent bonds. These characteristics make them play unique roles in different applications. Here, a comprehensive review is presented for establishing the connection between the basic properties and the performance, and revealing how sulfur doping has improved the applications. In-situ and post-treatment synthetic routes of S-doped carbons are summarized. Characteristics and properties of S-doped carbons including molecular structure, electronegativity, conductivity, hydrophilicity and co-doping effects are stated. And, the promising applications of S-doped carbons are presented. Especially, we put emphasis to explain the effects of S doping on the properties and application performances for S-doped carbons. At the end, a perspective is presented.