Ultralow Ru loaded CoNi bimetallic phosphides nanorods as efficient electrocatalyst for overall water splitting.

Efficient hydrogen/oxygen evolution reactions (HER/OER) bifunctional catalysts are critical to the overall water splitting efficiency. In this paper, a 1D rod-like structure bifunctional catalyst was firstly prepared, with ultralow Ru (1.19 wt%) loaded into CoNi bimetallic phosphides derived from 1D MOF-74-CoNi nanorods. Due to the strong interface interaction between Co and Ni bimetals which tunes the electronic structure and the Ru loading which increases the number of active sites of the catalyst, the electrocatalytic performance for both HER (8.7mV@10 mA cm−2) and OER (179.4mV@10 mA cm−2) under alkaline condition were significantly improved. The cell voltage of the full water splitting device assembled by the catalysts was only 1.47 V to achieve 10 mA cm−2. The rational materials design of 1D rod-like structured bimetallic phosphide catalysts in this work may suggest a new strategy for the preparation of other bifunctional electrocatalysts. The 1D rod-like structure bifunctional catalyst with ultralow Ru loaded into CoNi bimetallic phosphides exhibits outstanding water splitting performance in alkaline solution. [Display omitted] • Ru loaded CoNi bimetallic phosphides (Ru–CNP) bifunctional electrocatalyst was synthesized. • Ru loading could induce electron interactions and increase intrinsic activity. • The interface interaction between Co and Ni bimetals facilitates the HER/OER performance. • Ru–CNP exhibited excellent HER performance under alkaline and acidic conditions. • Ru–CNP presented superior OER and overall water splitting activity in alkaline solution. [ABSTRACT FROM AUTHOR]