Recently, it was demonstrated in a number of studies that transition metal chalcogenide obtained an increasing attention as a promising alternative electrocatalysts for hydrogen evolution reaction . Although transition metal chalcogenide have an appropriate hydrogen adsorption free energy, there still exist some obstacles that they have low electroconductivity and poor active sites. Herein, to make a breakthrough, we develop a template-directed method to synthesize Co-Mo-S hierarchical core shell nanorod array at Nickel foam. At first, the Co(CO3)0.5OH●0.11H2O nanowire array at nickel foam is fabicated by hydrothermal synthesis, which is considered as the template of the nanorod growing. Afterward, the precursor is treated by solvothermal synthesis in mixture of DMF and water. As we predicted, due to the ion exchange mechanism, the small-size Co-Mo-S nanosheets grow from the nanowire spontaneously, which construct a hierarchical core-shell nanorod structure. Through this simple strategy, we can achieve an electrocatalyst which has rich active sites exposed and structure stability to resist restacking without any complicate operations and expensive reagents. Remarkably, the current density of the optimum sample reached as high as 60 mA/cm2 at an overpotential of 166.4 mV vs RHE (in 1 M KOH), with Tafel slope of ~60.75 mV/dec, electrical double-layer capacity of 148.06 mF/cm2 and excellent long-term stability. Furthermore, in the comparison with CoS@NF and MoS2@NF, the Co-Mo-S hierarchical core-shell nanorod array has an obvious promotion of the electrocatalytic performance. Overall, we prepared Co-Mo-S hierarchical core-shell nanorod array at nickel foam with a simple template-directed method, which could be a prospective way to extend the future of transition metal chalcogenide in hydrogen evolution reaction.
1. Seh, Z. W., Kibsgaard, J., Dickens, C. F., Chorkendorff, I., Norskov, J. K., & Jaramillo, T. F. (2017). Combining theory and experiment in electrocatalysis: Insights into materials design. Science, 355(6321). doi:10.1126/science.aad4998
2. Jiang, J., Gao, M., Sheng, W., & Yan, Y. (2016). Hollow Chevrel-Phase NiMo3 S4 for Hydrogen Evolution in Alkaline Electrolytes. Angew Chem Int Ed Engl, 55(49), 15240-15245. doi:10.1002/anie.201607651