RESUMEN
The problem limiting the use of hydrogen evolution reactions in industry is the inability of electrocatalysts to operate stably at high current densities, so the development of stable and efficient electrocatalysts is important for hydrogen production by water splitting. By designing a rational interface engineering not only can the problem of limited number of catalytic sites in the catalyst be solved, but also can facilitate electron transfer, thus enhancing the efficiency of water splitting. Here, we designed a two-stage chemical vapour deposition method to construct NiC/Mo2C nanorod arrays on nickel foam to enhance the electrocatalytic ability of the catalysts, which exhibited efficient HER catalytic activity due to their special tentacle-like nanorod structure and abundant heterogeneous junction surfaces, which brought about abundant active sites as well as promoted electron transfer capability. The resulting catalysts provide current densities of 10, 100 and 500 mA cm-2 with overpotentials of 31, 153 and 264 mV, and exhibit excellent stability at current densities of 10 mA cm-2 for 200 h. This discovery provides a new idea for the rational design of catalysts with special morphologies.
RESUMEN
Alkaline water electrocatalysis is considered as one of the most reliable method to prepare the stable, inexpensive, and sustainable water splitting catalyst in large-scale. Recently, MoSe2 attracted great attention as a promising catalyst because of its high electrochemical activity and earth-abundant nature. In this paper, bionic NixSey/MoSe2 coralline-liked heterogeneous structures were successfully prepared on 3D nickel foam (NF) via a simple solvothermal process complemented by hydrothermal strategy with selenization and alkali treatment. Furthermore, to overcome the less active sites and poor electrical conductivity of MoSe2, we learned from the coral structure for the inspiration, and reported a novel hollow rod-like structure with increased active sites. Also, 1 T-2H MoSe2 improved the electrical conductivity of single phase MoSe2. We first confirmed the multi-phase of catalyst by XPS analysis with Mo 3d5/2 splited into two independent regions with the 2H and 1 T phase transition. The optimal ratio of NixSey/MoSe2/NF-5 exhibited excellent electrocatalytic activity towards HER in 1 M KOH, driving current densities of 10, 100 and 200 mA cm-2 at only 76, 165 and 194 mV with stability over 24 h. The work provides new ideas for the construction of transition metal selenides hollow rod array structures of efficient HER electrocatalysts.
