Single atom-decorated transition metal oxide nanomaterials for efficient oxygen evolution reaction

Abstract

As a promising technology for highly pure hydrogen production under mild conditions, electrochemical water splitting has been garnering substantial interest, while its efficiency and rate are primarily restricted by the sluggish anodic oxygen evolution reaction (OER). To date, the most efficient electrocatalysts for the OER have been Ru or Ir-based nanomaterials, but features of high price, scarcity and instability limit their massive utilization in water splitting. Therefore, developing effective, inexpensive and stable electrocatalysts is critical for large-scale water splitting. In this review, the OER mechanisms were first discussed in detail and then the principles for designing advanced single atom-decorated transition metal oxide-based OER electrocatalysts with excellent activities and stabilities were proposed accordingly. After that, recent advances in designing and preparing single atom-decorated transition metal oxide-based OER electrocatalysts were summarized in terms of synthetic methods and intrinsic nature to enhance the OER. Meanwhile, the roles of atomically dispersed sites in transition metal oxides for OER performance improvement were presented. Finally, we also highlighted the key challenges and future opportunities of single atom-decorated transition metal oxide-based OER electrocatalysts to provide new insights into synthesizing low-cost transition metal oxide electrocatalysts for water splitting.