Recent Advances in Perovskite Catalysts for Efficient Overall Water Splitting

Abstract

Hydrogen is considered a promising clean energy vector with the features of high energy capacity and zero-carbon emission. Water splitting is an environment-friendly and effective route for producing high-purity hydrogen, which contains two important half-cell reactions, namely, the anodic oxygen evolution reaction (OER) and the cathodic hydrogen evolution reaction (HER). At the heart of water splitting is high-performance electrocatalysts that efficiently improve the rate and selectivity of key chemical reactions. Recently, perovskite oxides have emerged as promising candidates for efficient water splitting electrocatalysts owing to their low cost, high electrochemical stability, and compositional and structural flexibility allowing for the achievement of high intrinsic electrocatalytic activity. In this review, we summarize the present research progress in the design, development, and application of perovskite oxides for electrocatalytic water splitting. The emphasis is on the innovative synthesis strategies and a deeper understanding of structure–activity relationships through a combination of systematic characterization and theoretical research. Finally, the main challenges and prospects for the further development of more efficient electrocatalysts based on perovskite oxides are proposed. It is expected to give guidance for the development of novel non-noble metal catalysts in electrochemical water splitting.

Regulation of perovskite oxides composition for the efficient electrocatalytic reactions

“…The oxidation states of A-site metal cation are generally fixed, and it is hardly to change by the redox reaction in the electrocatalytic process. [36,43] According to the apparent oxidation states of the doped atoms, we categorized and compiled the impacts of A-site doping on the electrocatalytic activities in perovskite oxides, including isovalent metal doping and heterovalent metal doping.…”

“…Oxygen vacancies in perovskites are the most favorable Schottky defects due to low-formation energies and stable structure of perovskites. [36,53,78] They were shown to greatly increase the electrocatalytic activities of perovskites. Additionally, the reaction process may change due to the oxygen vacancies.…”

“…There are many reviews focusing on perovskite electrocatalysts in terms of design principles, synthetic methods, and practical applications [19,35–37a,b] . Composition regulation strategies, as an essential subset of optimizing approaches, are rarely systematically and comprehensively reported.…”

A/B-Site Management Strategy to Boost Electrocatalytic Overall Water Splitting on Perovskite Oxides in an Alkaline Medium

“…Among the effective strategies that have been used to boost the electrocatalytic activity of perovskite, cationic doping to achieve the improved oxygen vacancy is particularly attractive. The A and B sites of perovskite-type oxides can be replaced by heterogeneous atoms to regulate the electronic structure of bulk oxides . According to the principle of charge balance, the oxidation state of transition metal elements at the B site may change when small amounts of elements with different valence states are added at the A site.…”

Photocatalytic Z‐scheme Overall Water Splitting: Insight into Different Optimization Strategies for Powder Suspension and Particulate Sheet Systems

“…Several reviews have been reported, discussing Z-schemes for overall water splitting and specifically proposing mechanisms, design strategies, and challenges. [1,3,7,13,[18][19][20][21][22][23][24] The focus of this review is the optimization strategies of powder suspension and particulate sheet Z-scheme photocatalytic systems for overall water splitting; in particular, different optimization strategies for a powder suspension Z-scheme with a redox shuttle and particulate sheet Z-scheme are emphasized.…”