[IEEE 2020 IEEE 33rd International Conference on Micro Electro Mechanical Systems (MEMS) - Vancouver, BC, Canada (2020.1.18-2020.1.22)] 2020 IEEE 33rd International Conference on Micro Electro Mechanical Systems (MEMS) - Graphene Quantum Dots Induced NiCo <sub/>2</sub> S <sub/>4</sub> as an Efficient Electrocatalyst for Hydrogen Harvest

摘要： We made an efficient electrocatalyst for hydrogen harvest, with an overpotential as low as 0.131V to achieve a current density of 10 mA/cm2. The morphology of the material was extremely delicate: branches on the nanowire, and smaller twigs on the branches, such that the specific surface area was greatly enlarged. The two-step hydrothermal process improved performance of is easily accessible. The GQD/NiCo2S4 should mainly be ascribed to graphene quantum dots (GQDs), which induce morphology change of NiCo2S4 nanowires. The delicate morphology serves as a buffer for volume change, and also a reservoir for electrolytes to transport protons [1]. In the meaning time, GQDs inherit excellent properties from both graphene and quantum dots, improving conductivity. Moreover, the addition of GQDs creates numerous defects in both the basal and edge planes for the diffusion of protons and thus help overcome the sluggish redox kinetics of the electrode, leading to improved overall performances [2].