MoS2 Decorated Carbon Nanofibers as Efficient and Durable Electrocatalyst for Hydrogen Evolution Reaction

Hydrogen is an efficient fuel which can be generated via water splitting, however hydrogen evolution occurs at high overpotential, and efficient hydrogen evolution catalysts are desired to replace state-of-the-art catalysts such as platinum. Here, we report an advanced electrocatalyst that has low overpotential, efficient charge transfers kinetics, low Tafel slope and durable. Carbon nanofibers (CNFs), obtained by carbonizing electrospun fibers, were decorated with MoS2 using a facile hydrothermal method. The imaging of catalyst reveals a flower like morphology that allows for exposure of edge sulfur sites to maximize the HER process. HER activity of MoS2 decorated over CNFs was compared with MoS2 without CNFs and with commercial MoS2. MoS2 grown over CNFs and MoS2-synthesized produced about 374 and 98 times higher current density at −0.30 V (vs. Reversible Hydrogen Electrode, RHE) compared with the MoS2-commercial sample, respectively. MoS2-commercial, MoS2-synthesized and MoS2 grown over CNFs showed a Tafel slope of 165, 79 and 60 mV/decade, capacitance of 0.99, 5.87 and 15.66 mF/cm2, and turnover frequency of 0.013, 0.025 and 0.54 s−1, respectively. The enhanced performance of MoS2-CNFs is due to large electroactive surface area, more exposure of edge sulfur to the electrolyte, and easy charge transfer from MoS2 to the electrode through conducting CNFs