Engineering different B doping modes on Ru active sites for efficient alkaline hydrogen evolution

Revealing the inner relationship between different active sites is of great significance to the rational design of highly efficient electrocatalysts for HER. Herein, two doping modes of boron, doping on the surface of Ru (B-Ru/CNT) and into carbon nanotubes (Ru/B-CNT), have been undertaken by using closo-[B12H12]2- as a B precursor through in situ reduction and calcination. According to experimental and DFT calculation results, the two B doping methods can both help reduce the electron density of Ru, which favors an enhancement in HER performance. More importantly, B doped into supports can further improve charge transfer efficiency. As a result, Ru/B-CNT exhibits an impressive HER performance (eta 10 = 15 mV) with fast reaction kinetics, as well as outstanding stability, which is much higher than those of undoped and surface-doped Ru-based catalysts. Two doping modes of B, direct doping on the Ru surface and doping into CNT, both modulate the electron density of Ru for high intrinsic activity, while the latter further improves charge transfer efficiency to accelerate reaction kinetics.