Water electrolysis as an important and facile strategy to generate hydrogen has attracted great attention, and efficient electrocatalysts play a key role in hydrogen evolution reaction (HER). Herein, vertical graphene (VG)-supported ultrafine NiMo alloy nanoparticles (NiMo@VG@CC) were fabricated successfully via electro-depositing as efficient self-supported electrocatalysts for HER. The introduction of metal Mo optimized the catalytic activity of transition metal Ni. In addition, VG arrays as the three-dimensional (3D) conductive scaffold not only ensured high electron conductivity and robust structural stability, but also endowed the self-supported electrode large specific surface area and exposed more active sites. With the synergistic effect between NiMo alloys and VG, the optimized NiMo@VG@CC electrode exhibited a low overpotential of 70.95 mV at 10 mA cm−2and a remarkable stable performance over 24 h. This research is anticipated to offer a powerful strategy for the fabrication of high-performance hydrogen evolution catalysts.Keywords:vertical graphene;NiMo alloy;high surface area;hydrogen evolution reaction;electrodeposition
Ya Liu,Wenzhu Tang,Gaowei Zhang,Wenhao Chen,Qingze Chen,Chunlin Xiao,Shenghui Xie,Yejun Qiu
Developing stable and efficient electrocatalysts for hydrogen evolution reaction is of great significance for the production of clean hydrogen energy from water splitting. In this work, 3D AgNWs@NiMo/PU electrode was obtained by electrodepositing NiMo alloy onto three-dimensional silver nanowires conductive substrate (3D AgNWs/PU) which was uniformly assembled on the surface of the skeleton of a polyurethane sponge (PU). 3D AgNWs/PU provides good electrolyte permeability, rich active site attachment points, good electronic conductivity and electrocatalytic synergy, which greatly improves the catalytic activity. In addition, 3D AgNWs@NiMo/PU electrode does not need to use adhesive in the process of hydrogen evolution, which can improve the hydrogen evolution performance and stability of the electrode. Specifically, the optimized electrode (AgNWs@NiMo/PU-1200 s) exhibits excellent hydrogen evolution performance by achieving a low overpotential of 32 mV (vs. RHE) at a current density of 10 mA cm −2 , with a Tafel slope of 72 mV dec -1 (in 1 M KOH). More interestingly, it also has good stability after 10 h of stability test. Therefore, this study provides a feasible way to develop stable and efficient 3D HER electrocatalysts.