Amorphous-crystalline heterostructure for simulated practical water splitting at high-current-density

The catalyst for practical water electrolysis needs to maintain long-term stability and work effectively withstanding high-intensity gas evolution, which is extremely challenging. Heterostructure with an amorphous crystalline interface has been reported recently to availably enhance the catalytic performance of materials at high output. Herein, a wet chemical etching method realizes the hierarchical amorphous/crystalline heterostructure [(WO2-Ni17W3)/NiFe(OH)(x)]. It induces modulated electronic structure and abundant active sites with chemical stability, resulting in extraordinary catalytic activity for hydrogen evolution reaction (eta(10) = 31 mV, eta(1000) = 258 mV), oxygen evolution reaction (eta(50) = 240 mV, eta(1,000) = 336 mV), and overall water splitting (1.54/ 1.84 V at 50/1,000 mA cm(-2)). Besides, it can maintain at 1,000 mA cm(-2) stably for 120 h under simulated industrial condition (6.0 M KOH solution at 60 celcius) as a bifunctional catalyst. The coupled active phases and the in-situ formed heterojunction ensure an excellent performance at high current density. This strategy could be promoted to fabricate catalysts for practical water electrolysis.

Automated summary

This paper presents a hierarchical amorphous/crystalline heterostructure [(WO2-Ni17W3)/NiFe(OH)(x)] prepared by a wet chemical etching method as a catalyst, which exhibits extraordinary catalytic activity and stability for water electrolysis.