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Hydroxyl radical (•OH), a highly reactive oxygen species (ROS), is assumed as one of the most aggressive free radicals. This radical has a detrimental impact on cells as it can react with different biological substrates leading to pathophysiological disorders, including inflammation, mitochondrion dysfunction, and cancer. Quantification of this free radical in‐situ plays critical roles in early diagnosis and treatment monitoring of various disorders, like macrophage polarization and tumor cell development. Luminescence analysis using responsive probes has been an emerging and reliable technique for in‐situ detection of various cellular ROS, and some recently developed •OH responsive nanoprobes have confirmed the association with cancer development. This paper aims to summarize the recent advances in the characterization of •OH in living organisms using responsive nanoprobes, covering the production, the sources of •OH, and biological function, especially in the development of related diseases followed by the discussion of luminescence nanoprobes for •OH detection. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is a promising way for the sustainable production of hydrogen, but the efficiency of the overall water‐splitting reaction largely depends on the oxygen evolution reaction (OER) because of its sluggish kinetics. Herein, a series of hierarchical ZnCo2O4/Co3O4/NC‐CNT (NC‐CNT=nitrogen‐rich carbon nanotube) mesoporous dodecahedrons grafted to carbon nanotubes have been synthesized from ZnCo bimetallic zeolitic imidazolate frameworks (ZnCo‐ZIFs) through sequential pyrolysis in nitrogen and mild oxidation in air. The simultaneous modulation of oxygen vacancies, composition, and hierarchical mesoporous architecture remarkably enhanced their electronic conduction and the amount and reactivity of accessible actives; thus boosting their intrinsic activity in the OER. The optimal ZnCo2O4/Co3O4/NC‐CNT‐700 sample exhibited a large current density of 50 mA cm−2 at a potential of 1.65 V, a small Tafel slope of 88.5 mV dec−1, and superior stability in alkaline media. This work should provide a facile strategy for the rational design of advanced OER catalysts by simultaneous engineering of oxygen vacancies and composition. Hard graft: Simultaneous modulation of oxygen vacancies and hierarchical mesoporous architecture in ZnCo2O4/Co3O4/NC‐CNT (NC‐CNT=nitrogen‐rich carbon nanotube; see figure) dodecahedrons derived from ZnCo bimetallic zeolitic imidazolate frameworks (ZnCo‐ZIFs) with grafted carbon nanotubes resulted in superior electrochemical properties towards the oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is a promising way for the sustainable production of hydrogen, but the efficiency of the overall water-splitting reaction largely depends on the oxygen evolution reaction (OER) because of its sluggish kinetics. Herein, a series of hierarchical ZnCo 2 O 4 /Co 3 O 4 /NC-CNT (NC-CNT=nitrogen-rich carbon nanotube) mesoporous dodecahedrons grafted to carbon nanotubes have been synthesized from ZnCo bimetallic zeolitic imidazolate frameworks (ZnCo-ZIFs) through sequential pyrolysis in nitrogen and mild oxidation in air. The simultaneous modulation of oxygen vacancies, composition, and hierarchical mesoporous architecture remarkably enhanced their electronic conduction and the amount and reactivity of accessible actives; thus boosting their intrinsic activity in the OER. The optimal ZnCo 2 O 4 /Co 3 O 4 /NC-CNT-700 sample exhibited a large current density of 50 mA cm -2 at a potential of 1.65 V, a small Tafel slope of 88.5 mV dec -1 , and superior stability in alkaline media. This work should provide a facile strategy for the rational design of advanced OER catalysts by simultaneous engineering of oxygen vacancies and composition., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hydrogen produced from electrocatalytic water splitting is a promising route due to the sustainable powers derived from the solar and wind energy. However, the sluggish kinetics at the anode for water splitting makes the highly effective and inexpensive electrocatalysts desirable in oxygen evolution reaction (OER) by structure and composition modulations. Metal-organic frameworks (MOFs) have been intensively used as the templates/precursors to synthesize complex hollow structures for various energy-related applications. Herein, an effective and facile template-engaged strategy originated from bimetal MOFs is developed to construct hollow microcubes assembled by interconnected nanopolyhedron, consisting of intimately dominant FeNi alloys coupled with a small NiFe 2 O 4 oxide, which was confined within carbonitride outer shell (denoted as FeNi/NiFe 2 O 4 @NC) via one-step annealing treatment. The optimized FeNi/NiFe 2 O 4 @NC exhibits excellent electrocatalytic performances toward OER in alkaline media, showing 10 mA·cm -2 at η = 316 mV, lower Tafel slope (60 mV·dec -1 ), and excellent durability without decay after 5000 CV cycles, which also surpasses the IrO 2 catalyst and most of non-noble catalysts in the OER, demonstrating a great perspective. The superior OER performance is ascribed to the hollow interior for fast mass transport, in situ formed strong coupling between FeNi alloys and NiFe 2 O 4 for electron transfer, and the protection of carbonitride layers for long stability.