Sulfur-doped porous carbons: Synthesis and applications

Heteroatom doping of carbon materials may become the “Next Big Thing” in materials science further enhancing research concerning carbon nanostructures. In particular, the S-doped porous carbons have gained a great deal of attention in the last few years. They are already proven to be versatile functional materials with a wide range of potential applications, including heterogeneous catalysis, sorption, as well as in the areas of energy conversion and storage. To date, a few approaches have been developed to intrinsically blend sulfur into the carbon matrix. Yet there is still a need to design new porous structures with controllable porosity and well defined chemical status of sulfur doped into the carbon matrix. In this review, we summarize recent reports on the preparation of S-doped carbons, with special emphasis on porous carbons with intrinsically doped sulfur. The effect of S-doping on the properties determining applications is delineated. Special attention is paid to differentiate between elemental sulfur impregnation, intercalation, surface functionalization and S bulk doping of porous carbons. To this end, synthesis and applications of S-impregnated, S-functionalized and S-intercalated carbons are shortly discussed before the intrinsically S-doped carbons are presented in detail. The importance of the sulfide –C–S–C– system for the properties of S-doped carbon is stressed. At the very end, Se-doped carbons are shortly presented as a promising next generation of chalcogen-doped carbon.