Quasi-atomic-scale platinum anchored on porous titanium nitride nanorod arrays for highly efficient hydrogen evolution

Abstract

Highly efficient electrocatalytic hydrogen evolution reaction (HER) is achieved by constructing uniformly dispersed quasi-atomic-scale Pt on porous conductive titanium nitride nanorod arrays (PtTiN NAs). The PtTiN NAs demonstrate high HER efficiencies both in acid (0.5 M H2SO4) and alkaline media (1 M KOH) with the overpotentials of 39.7 mV and 139 mV at the current density of 10 mA cm−2, respectively, which is comparable to that of commercial 20 wt % Pt/C under the same experimental condition. In addition, the Tafel slopes of PtTiN NAs (38.6 mV dec−1 in acid and 98.3 mV dec−1 in alkaline media) are much lower than that of commercial Pt/C. More remarkably, the PtTiN NAs display a much higher current retention of 91.6% after continuous test for 60 h in 0.5 M H2SO4 comparing to 46.9% of Pt/C after 30 h cycling. The excellent HER performance of as-prepared PtTiN NAs are attributed to the abundant available reaction sites from the uniformly distributed quasi-atomic-scale Pt, the suppressed aggregation of Pt by the strong metal-substrate interaction between Pt and TiN, and the superior electron transfer caused by high electric conductivity TiN substrate. Our designed structure provides an ideal catalytic system for efficient HER, which may inspire the design and synthesis of other high efficiency electrocatalytic systems.