Exploring active, stable, and low-cost bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is crucial for water splitting technology associated with renewable energy storage in the form of hydrogen fuel. Here, a newly designed antiperovskite-based hybrid composed of a conductive InNNi core and amorphous InNi(oxy)hydroxide shell is first reported as promising OER/HER bifunctional electrocatalyst. Prepared by a facile electrochemical oxidation strategy, such unique hybrid (denoted as EO-InNNi ) exhibits excellent OER and HER activities in alkaline media, benefiting from the inherent high-efficiency HER catalytic nature of InNNi antiperovskite and the promoting role of OER-active InNi(oxy)hydroxide thin film, which is confirmed by theoretical simulations and in situ Raman studies.
View Article and Find Full Text PDFThe state-of-the-art active HER catalysts in acid media (e.g., Pt) generally lose considerable catalytic performance in alkaline media mainly due to the additional water dissociation step.
View Article and Find Full Text PDFThe oxygen evolution reaction (OER) is pivotal in multiple gas-involved energy conversion technologies, such as water splitting, rechargeable metal-air batteries, and CO /N electrolysis. Emerging anion-redox chemistry provides exciting opportunities for boosting catalytic activity, and thus mastering lattice-oxygen activation of metal oxides and identifying the origins are crucial for the development of advanced catalysts. Here, a strategy to activate surface lattice-oxygen sites for OER catalysis via constructing a Ruddlesden-Popper/perovskite hybrid, which is prepared by a facile one-pot self-assembly method, is developed.
View Article and Find Full Text PDFDeveloping efficient and low-cost electrocatalysts for the oxygen evolution reaction (OER) is of paramount importance to many chemical and energy transformation technologies. The diversity and flexibility of metal oxides offer numerous degrees of freedom for enhancing catalytic activity by tailoring their physicochemical properties, but the active site of current metal oxides for OER is still limited to either metal ions or lattice oxygen. Here, a new complex oxide with unique hexagonal structure consisting of one honeycomb-like network, Ba Sr (Co Fe ) O (hex-BSCF), is reported, demonstrating ultrahigh OER activity because both the tetrahedral Co ions and the octahedral oxygen ions on the surface are active, as confirmed by combined X-ray absorption spectroscopy analysis and theoretical calculations.
View Article and Find Full Text PDFOxygen evolution reaction (OER) is crucial in many renewable electrochemical technologies including regenerative fuel cells, rechargeable metal-air batteries, and water splitting. It is found that abundant active sites with favorable electronic structure and high electrical conductivity play a dominant role in achieving high electrocatalytic efficiency of perovskites, thus efficient strategies need to be designed to generate multiple beneficial factors for OER. Here, highlighted is an unusual super-exchange effect in ferromagnetic perovskite oxide to optimize active sites and enhance electrical conductivity.
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