Easy access to trace-loading of Pt on inert Ni3N nanoparticles with significantly improved hydrogen evolution activity at entire pH values

Abstract

Compared with 2D metallic Ni3N nanosheets as a potential alternative to Pt-based catalyst, Ni3N nanoparticles exhibit inert electrocatalytic hydrogen evolution reaction (HER) activity due to their poor conductivity. In this work, we demonstrated that the HER activity of inert Ni3N nanoparticles could be significantly improved through high dispersion of trace-loaded Pt on their surface. In detail, Ni3N/Ni@C with controllable Ni content was prepared via the urea-urea-glass-route by controlling the calcination temperature and time based on the thermal unstability of Ni3N. Followed by the galvanic replacement between Ni and a platinum precursor, Ni3N/Ni@C decorated with a trace amount (0.45 wt%) of Pt was simply prepared. The trace-loaded catalyst exhibited greatly enhanced HER activity and stability in entire pH range including in 0.5 M H2SO4, 1.0 M KOH and 0.2 M PBS (pH = 7), which could be comparable to commercial Pt/C (20 wt%) catalyst. For example, they held low overpotential of 117 mV at 10 mA/cm2, small Tafel slope of 47.3 mV/dec, and large electrochemical surface area of 60.24 mF/cm2 in 0.5 M H2SO4. The present work provides an intriguing strategy for developing trace loadings of noble metal electrocatalysts on inert materials with high HER performance.