Non‐Noble‐Metal‐Based Electrocatalysts toward the Oxygen Evolution Reaction

The roles of oxygen vacancies in electrocatalytic oxygen evolution reaction

The modulation of electron density is an effective option for efficient alternative electrocatalysts. Here, p-n junctions are constructed in 3D free-standing FeNi-LDH/CoP/carbon cloth (CC) electrode (LDH=layered double hydroxide). The positively charged FeNi-LDH in the space-charge region can significantly boost oxygen evolution reaction. Therefore, the j at 1.485 V (vs. RHE) of FeNi-LDH/CoP/CC achieves ca. 10-fold and ca. 100-fold increases compared to those of FeNi-LDH/CC and CoP/CC, respectively. Density functional theory calculation reveals OH- has a stronger trend to adsorb on the surface of FeNi-LDH side in the p-n junction compared to individual FeNi-LDH further verifying the synergistic effect in the p-n junction. Additionally, it represents excellent activity toward water splitting. The utilization of heterojunctions would open up an entirely new possibility to purposefully regulate the electronic structure of active sites and promote their catalytic activities.

Utilizing the Space-Charge Region of the FeNi-LDH/CoP p-n Junction to Promote Performance in Oxygen Evolution Electrocatalysis.

The development of cost-effective catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for enhancing the energy efficiency of many electrochemical energy conversion and storage devices. Owing to their low cost and high activity, transition metal oxides have attracted much attention as alternative electrocatalysts to replace the currently used noble metal-based catalysts. Anion defects (e.g., oxygen vacancies, interstitials, and anion dopants) can significantly change the electronic structure of oxides or the stability of adsorbed intermediates, thus greatly enhancing the electrocatalytic activities of the oxide surface. Anionic defect engineering represents a potential new direction for rational design of high-performance electrocatalysts. In this review, recent progress in manipulating the anion defects in transition metal oxides for enhancing their activity and stability is summarized and the proposed mechanisms for enhanced performance are discussed in detail. Challenges and prospects are also discussed in the development of a new generation of highly efficient ORR and OER electrocatalysts.

Anionic defect engineering of transition metal oxides for oxygen reduction and evolution reactions

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial reactions in energy conversion and storage systems including fuel cells, metal–air batteries, and electrolyzers. Developing low-cost, highefficiency, and durable non-noble bifunctional oxygen electrocatalysts is the key to the commercialization of these devices. Here, based on an in-depth understanding of ORR/OER reaction mechanisms, recent advances in the development of non-noble electrocatalysts for ORR/OER are reviewed. In particular, rational design for enhancing the activity and stability and scalable synthesis toward the large-scale production of bifunctional electrocatalysts are highlighted. Prospects and future challenges in the field of oxygen electrocatalysis are presented.

Recent Advances in Non‐Noble Bifunctional Oxygen Electrocatalysts toward Large‐Scale Production

A Facile Strategy to Construct Amorphous Spinel-Based Electrocatalysts with Massive Oxygen Vacancies Using Ionic Liquid Dopant

https://onlinelibrary.wiley.com/doi/pdf/10.1002/aenm.201870121

Electrocatalysts: A Facile Strategy to Construct Amorphous Spinel-Based Electrocatalysts with Massive Oxygen Vacancies Using Ionic Liquid Dopant (Adv. Energy Mater. 27/2018)

Feng He

Papers

A Facile Strategy to Construct Amorphous Spinel-Based Electrocatalysts with Massive Oxygen Vacancies Using Ionic Liquid Dopant

Electrocatalysts: A Facile Strategy to Construct Amorphous Spinel-Based Electrocatalysts with Massive Oxygen Vacancies Using Ionic Liquid Dopant (Adv. Energy Mater. 27/2018)