Ru-Doped Platelet-Like Ni2P Nanostructure for Electrocatalytic HER and ORR Applications

Abstract

Extended AbstractIn this work, for the first time, a unique Ru-doped platelet-like Ni 2 P nanostructure, was successfully prepared based on a simple one-pot synthesis method. Due to its particular platelet-like structure, the as-synthesized Ru-doped Ni 2 P catalyst not only exhibits a remarkably enhanced electrocatalytic hydrogen evolution reaction (HER) performances with an onset potential of 35 mV, tafel slope of 34 mV dec -1 and long-term stability, but also possesses superior oxygen evolution reaction (OER) properties with an onset potential of 1.54 V and robust durability, exceeding the performance of an individual Ru or Ni 2 P component and comparable to that of commercial 20% Pt/C, IrO 2 catalysts. As confirmed by HRTEM, line-scan, elemental-mapping and electrochemical analysis, the superior electrocatalytic bifunctionality of Rudoped Ni 2 P nanostructure can be attributed to the combined influence of the following factors: (1) The good intrinsic electrocatalytic properties for the exposed abundant (001) planet of Ni 2 P [1][2][3][4] ; (2) The special platelet-like structure ensures larger specific surface area compared to simple flat or hollow nanosheets, along with more accessible active sites caused by defects, facilitating their electrocatalytic process; (3) The introduced metallic Ru enables faster electron transfer rate of semiconductor Ni 2 P and moderate hydrogen adsorption energy, and thus are responsible for their remarkable electrocatalytic bifunctionality [5], [6] . In summary, such platelet-like Ru-doped Ni 2 P nanostrufcture is expected to serve as a new kind of robust catalyst for HER and OER applications. This study opens up new avenues for the design of novel highefficiency bifunctional electrocatalysts for use in water-splitting, fuel cells and other renewable energy technology fields. References[1] P. Xiao, W. Chen and X. Wang, "A review of phosphide-based materials for electrocatalytic hydrogen evolution," Adv. Energy Mater., vol. 5, pp. 1500985 (1-13), 2015.[2] Y. Shi and B. Zhang, "Recent advances in transition metal phosphide nanomaterials: synthesis and applications in hydrogen evolution reaction," Chem. Soc. Rev., vol. 45, pp. 1529-1541 A. Han, H. Chen, Z. Sun, J. Xu and P. Du, "High catalytic activity for water oxidation based on nanostructured nickel phosphide precursors," Chem. Commun., vol. 51, pp. 11626-11629, 2015. [4] E. J. Popczun, J. R. McKone, C. G. Read, A. J. Biacchi, A. M. Wiltrout, N. S. Lewis and R. E. Schaak, "Nanostructured nickel phosphide as an electrocatalyst for the hydrogen evolution reaction," J. Am. Chem. Soc., vol. 135, pp. 9267-9270, 2013. [5] L. A. Stern, L. Feng, F. Song and X. Hu, "Ni 2 P as a Janus catalyst for water splitting: the oxygen evolution activity of Ni 2 P nanoparticles," Energy Environ. Sci., vol. 8, pp. 2347Sci., vol. 8, pp. -2351Sci., vol. 8, pp. , 2015.[6]X. Wang, R. Tong, Y. Wang, H. Tao, Z. Zhang and H. Wang "Surface roughening of nickel cobalt phosphide nanowire arrays/Ni foam for enhanced hydrogen evolution activity," ACS Appl.