Various S-bonding configurations existing in sulfur-doped reduced graphene oxide (S-rGO) show different electronic structures and physiochemical properties. Thus, understanding the properties of unique S-bonding configurations requires the construction of S-rGO with only single configuration. Here, we synthesized S-rGO with a pure thiophene− sulfur configuration through a simple and low-cost hydrothermal method by simply controlling the oxidation degree of the graphene oxide (GO) precursor. Through the use of a GO precursor with a high content of C−O groups, pure doping of the thiophene−sulfur configuration in the rGO can be achieved. Further electrochemical characterization reveals an increased electrocatalytic activity of the pure thiophene−sulfur-doped S-rGO in the oxygen reduction reaction, indicating the important role of thiophene−sulfur. The present work deepens the understanding of the functions of doped nonmetal elements in carbon materials in electrocatalysis and helps in the design of high performance electrocatalysts.

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