Onion-like Core-shell Ni@C supported on carbon nanotubes decorated with low Pt as a superior electrocatalyst for hydrogen evolution reaction

Abstract

The development of cost-effective electrocatalysts for efficient hydrogen evolution reaction (HER) is of paramount significant for future renewable energy. Pt-based catalysts have been recognized as the most effective electrocatalysts for HER. Developing low-cost and excellent electrocatalysts is a crucial step to achieve its commercial application, because of its high cost and scarcity. In this study, we fabricate carbon encapsulated Ni nanoparticles (NPs) and low Pt NPs supported on carbon nanotubes (CNTs). These samples are synthesized through catalytic decomposition of methane on Ni/CNT catalyst, and Ni/CNT is prepared using the polyol reduction method. Ni@C and Pt are uniformly dispersed on the CNTs. Ni@C-10 with low Pt loading (0.49wt%) exhibits superior HER activity and excellent stability even higher than that of commercial 20wt% Pt/C. Ni@C-10 (Pt loading is 4.3 µg cm−2 on the working electrode) exhibits negligible onset potential, and only 40 mV vs RHE potential is required to support 10 mA cm−2 in 0.1 M H2SO4 aqueous solution, which is better than 19 mV of Pt/C (59 mV). It achieve a low Tafel slope of 31.7 mV dec−1 close to Pt/C (29.3 mV dec−1). After 2000 cycles, it exhibits negligible potential shift (1 mV). This study provides an avenue for developing the efficient catalysts for HER with low Pt loading.