ZIF-67 derived CoNiP-N-C as an efficient catalyst for water splitting

Abstract

Transition metal phosphides (TMPs) are deemed viable electrocatalysts for electrocatalytic water splitting reactions, which facilitate clean hydrogen production. Among the various synthesis methods, the synthesis of TMPs through simple, green and sustainable pathways remains a challenge. In this study, an ecologically friendly phytic acid-assisted phosphorylation strategy was utilized to fabricate nitrogen-doped carbon skeleton supported CoNiP nanoparticles (CoNiP-N-C). Benefiting from the incorporation of a carbon matrix, agglomeration of the TMPs was well avoided, leading to the significant exposure of active sites, which significantly enhanced the catalytic activity of CoNiP-N-C for the hydrogen evolution reaction (HER) as well as the oxygen evolution reaction (OER) in alkaline solutions. The electrocatalytic test unveiled that as for the CoNiP-N-C catalyst, overpotentials of almost 170 mV and 350 mV were needed to achieve the current density of 10 mA cm⁻² for the HER and OER, respectively. Meanwhile, excellent overall water splitting activity was achieved as well, exhibiting a current density of 10 mA cm⁻² at 1.69 V. This study suggests a new method for the preparation of novel TMPs and provides an excellent electrocatalyst for overall water splitting.