Molybdenum disulfide with enlarged interlayer spacing decorated on reduced graphene oxide for efficient electrocatalytic hydrogen evolution

Layered transition metal dichalcogenides especially MoS 2 is favorable to be the low-cost alternative to Pt-based electrocatalysts for water splitting. Defect-rich MoS 2 nanosheets exhibiting enlarged interlayer spacing of 9.2 Å were synthesized via a solvothermal method, in which trithiocyanuric acid (TTCA) was used as a sulfur source. In addition, we synthesized MoS 2 with L -cysteine for comparison. To improve the conductivity and quantity of active exposed sites of MoS 2 nanosheets, the rGO nanosheets were introduced to hybridize with MoS 2 . With the addition of rGO, the MoS 2 /rGO hybrids exhibit different morphologies and larger interlayer spacing of 9.5 Å. Furthermore, the enhanced performance for hydrogen evolution reaction is attributed to the synergistic effect between the MoS 2 nanosheets and rGO substrates. MoS 2 /rGO-2 possesses an onset overpotential of 118 mV, a small Tafel slope of 51 mV/dec, high double-layer capacitance ( C dl ) of 15.27 mF/cm 2 , and superior cycling stability over 1000 cycles in acidic conditions.