Semiconductors modified gourd-shaped hollow PtNi and their directional electron and mass transfer effects

Maximization of the utilization of electronic energy and enhancement of mass transfer are important goals in designing high-performance electrocatalytic PtNi nanoalloys. However, realization of such a combination of these properties into Pt based electrocatalysts remains a significant challenge. In an effort targeted at attaining these goals, we prepared several semiconductors (BiVO4, CdS and TiO2) modified, gourd-shaped hollow PtNi nanocomposites. We observed that among members of this group, BiVO4 modified PtNi (denoted as BiVO4/PtNi) displays optimal directional electron and mass transfer, which are attributed to the closeness of the work functions of BiVO4 and PtNi, and a unique gourd-shaped, hollow structure. Moreover, BiVO4/PtNi displays remarkable electrocatalytic performance in the hydrogen evolution reaction, in terms of low overpotential of 23 mV to drive the current density of 10 mA cm(-2) and a low Tafel slope of 40 mV dec(-1) in alkaline natural seawater. Furthermore, this nanocomposite exhibits high stability during a 20-h durability test that greatly exceeds that of commercial Pt/C. The results of this investigation show that new approaches exist for designing novel nano-materials that have superior performance as electrocatalysts or in other practical applications.

Automated summary

The utilization of electronic energy and mass transfer in electrocatalytic PtNi nanoalloys is crucial for their high performance. However, achieving these goals in Pt-based electrocatalysts remains a challenge. In this study, we prepared gourd-shaped hollow PtNi nanocomposites modified with semiconductors (BiVO4, CdS, and TiO2). Among them, BiVO4 modified PtNi showed optimal electron and mass transfer due to the similarity in work functions and unique hollow structure. This nanocomposite exhibited remarkable electrocatalytic performance in the hydrogen evolution reaction, with low overpotential and high stability.