Developments of Metal Phosphides as Efficient OER Precatalysts

Abstract

Over the last 2 years, it has been observed that metal phosphides have emerged as efficient electrocatalysts for both hydrogen and oxygen evolution reactions (HER and OER). However, while the HER has been immensely studied, the OER is limited. The chemistry in the OER is more complicated and involves irreversible surface oxidations of these materials and transforms them to their corresponding oxide/oxyhydroxide. Interestingly, these in situ changes have been widely observed generating more active catalysts with superior performance. Phosphides of Fe, Co, and Ni with different compositions have been proved as efficient catalysts for water oxidation. Considering their importance, structures, compositions, surface modifications, and also in situ transformation during electrolysis, this Perspective provides state-of-the-art views of their current developments and future prospects.

Construction of Hierarchical Co–Fe Oxyphosphide Microtubes for Electrocatalytic Overall Water Splitting

“…Besides, the electrolyzer shows good stability with about 93% of the initial activity retained after the stability test of 10 h ( Figure S17, Supporting Information). [45] This hypothesis can be proved by the HRTEM observation, which shows the formation of the surface amorphous layer ( Figure S19a, Supporting Information). However, the sharp edges of the nanoflakes become roundish, which might be induced by the transformation of the oxyphosphides on the surface into amorphous hydroxides during the OER.…”

Preparation of Yolk–Shell‐Structured CoxFe1−xP with Enhanced OER Performance

“…[14] More recently,m etal sulfides have been used as OER catalysts because of their betterintrinsic electrical conductivity.S hanmugam and co-workers prepared CoS 2 (400)/N, S-GO, which showedb etter electrocatalytic performance than preciousm etal catalysts. [9,17] Recently,t ransition metal phosphidesh ave attracted researchers because of their excellent OER properties [9] (e.g.,h igh activity,o utstanding durability,a nd low cost). [16] Although metal sulfides show higher OER performance, their poor structural stabilityd uring the OER process limits their implementation in OER-related applications.…”

Reduced Graphene Oxide‐Wrapped Co9–xFexS8/Co,Fe‐N‐C Composite as Bifunctional Electrocatalyst for Oxygen Reduction and Evolution

“…Over the past few decades, tremendous endeavors have been made on the development of nonnoble metal‐based OER catalysts, including transition metal oxides, layered double hydroxide, selenides, phosphides, and chalcogenides . Among them, the transition metal sulfides (TMSs), with relatively lower intrinsic electrical resistivity, have been considered as promising alternative OER catalysts .…”