Sulfur-fixation strategy toward controllable synthesis of molybdenum-based/carbon nanosheets derived from petroleum asphalt

Abstract

Rational yet high value-added utilization of petroleum asphalt is still a persistent challenge, especially faced with the S atoms in it. Inspired by the hydrodesulfurization process, here, an in-situ sulfur-fixation strategy has been developed to controllably prepare versatile molybdenum-based/carbon nanosheets (Mo-based/CNs) composites. Importantly, this synthetic protocol can realize the anchoring of S atoms derived from petroleum asphalt to the great extent through doped into carbon skeletons and bonded with Mo atoms, which avoids the exhaust gas pollution during the fabrication process. The optimized Mo-based/CNs with in-situ generated Mo6S9.5 species exhibit a high capacitance of 512 F g−1 at 1 A g−1, and the assembled asymmetric supercapacitors can deliver a high energy density up to 30.8 Wh kg−1 at a power density of 800 W kg−1 and superb electrochemical stability. Furthermore, the compositions of Mo-based/CNs can be further tailored to produce Mo6S9.5 and Mo2C active species by tuning the amount of Mo precursors, and the resultant Mo-based/CNs present good catalytic activity and stability for hydrogen evolution reactions. This may provide a new perspective for the high value-added utilization of low-cost petroleum asphalt.