Size Effects of MoS2 on Hydrogen and Oxygen Evolution Reaction

Molybdenum disulfide (MoS2) has been widely used as a catalyst for the bifunctional activities of hydrogen and oxygen evolution reactions (HER OER). Here, we investigated size dependent HER OER performance MoS2. The smallest (90 nm) MoS2 exhibits lowest overpotential −0.28 V at −10 mAcm−2 1.52 300 with Tafel slopes 151 176 mVdec−1 OER, respectively, compared to bigger sizes (2 μm 6 μm) better is attributed high electrochemical active surface area (6 × 10−4 cm2) edge sites low charge transfer resistance (18.1 Ω), confirming that smaller nanosheets have catalytic behavior.