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FeNiOOH is regarded as the most stable active species in the oxygen evolution reaction (OER), but the high oxidation energy of NiOOH poses a challenge to directly synthesize FeNiOOH as a real OER catalyst. Herein, an anion‐mediated kinetically controlled strategy is proposed, coupled with cation‐induced geometric topology modulation, to directly synthesis FeNiOOH with ultra‐thin, densely packed nanosheet architectures. Specifically, the Cl−‐mediated in situ generation of hypochlorous acid promotes the direct formation of NiFeOOH. Concurrently, high‐valence competitive Ru3+ mitigate electrostatic repulsion, fostering a compact and densely packed assembly of Ru/FeNiOOH nanosheet branches. Furthermore, the intrinsic electron‐capturing ability of FeOOH, in synergy with the stabilizing effect of doped Ru atoms, further promote the formation and stabilization high‐valence NiOOH. Consequently, the hierarchical Ru/FeNiOOH@NiPOx nanoarray catalyst displays exceptional OER performance, with an overpotential of 172 mV at 10 mA cm−2 and outstanding stability. This study provides a novel strategy to directly construct a real catalyst. [ABSTRACT FROM AUTHOR]

Surface reconstruction that produces real active species for catalytic reactions generally occurs during electrocatalytic water splitting, but overcoming the reconstruction level‐mass activity‐stability trade‐off is a grand challenge. A cation‐doping in conjunction with a geometrical topology strategy is proposed to concurrently realize deep reconstruction and self‐optimization of FeNi phosphide nanoarrays during an electrochemical activation process. The doped Zn cation induces a deep reconstruction of FeNiP@Fe2P precatalyst by continuously dissolving Fe2P and re‐depositing as amorphous FeOOH that solders Ni2P nanoparticles, forming small ultra‐thin nanosheets with abundant amorphous‐crystalline interfaces for structural stability. Moreover, multichannel topology exhibits an unusual ability to optimize their morphology via finally evolving into multi‐microchannel tubular nanoarrays comprising of interconnected‐nanosheets with a very loose structure for enhanced electrolyte permeability, mass transfer, and accessibility of active sites. The reconstructed Zn‐Ni2P/FeOOH superstructure catalysts reach 10 mA cm−2 current density at an ultra‐low overpotential of 11 mV for hydrogen evolution reactions (HER). Impressively, when assembled as a two‐electrode cell with Zn‐FeNiP@Zn‐Fe2P as anode and Zn‐Ni2P/FeOOH as cathode, it delivers current densities of 10 mA cm−2 at a record low cell voltage of 1.40 V. This strategy provides a novel avenue to promote reconstruction for achieving high catalytic performance. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) activity of Ni-based oxyhydroxides greatly hinges on their phase structures, which are mainly γ and β phases: the former has higher intrinsic activity than the latter. However, it is still a grand challenge to purposefully generate γ phase, rather than β phase. Here, we propose a cation-doping strategy to generate γ phase by taking Zn-doped NiFeP/N-doped C (Z-NFP/N-C) precatalyst as a model. In contrast to the case of NFP/N-C that can only be reconstructed into β-NiFeOOH, Zn dopant will induce the formation of γ-NiFeOOH during an electrochemical process. Specifically, the doped Zn cation will promote the dissolution of NiFeP and redeposition of NiFeOOH on the surface. Simultaneously, the cation defects generated by Zn leaching will force the surrounding Ni valence state to rise for charge balance and will attract more K+ in the solution to intercalate into the interlayer of NiFeOOH, resulting in the formation of γ-NiFeOOH. As a result, the γ-NiFeOOH/Z-NFP/N-C exhibits superior OER performance: a low overpotential of 216 mV at 10 mA cm−2 and satisfactory stability (100 h at 17 mA cm−2). Our study offers a practical approach to produce highly active "true catalyst" for efficient water splitting. [ABSTRACT FROM AUTHOR]

Nickel–iron oxyhydroxides are among the most active electrocatalysts, but their sluggish kinetic of oxygen evolution reaction (OER) limits the energy efficiency toward overall water splitting. Here, we present a "cascade electron transfer" strategy through spurring unidirectional electron transfer among different metal sites in Mn-doped FeNiOOH@FeNiP to boost OER and overall water splitting. The Mn doping induces a cascade electron transfer from Ni to Fe and then to Mn via metal-O-metal bridge, thus promoting the oxidation Ni and Fe centers, which in turn help charge transfer by increasing the covalency between metal-O bonds to optimize the bonding strength between metal and adsorbed oxygen species. Consequently, the optimal Mn–FeNiOOH@FeNiP delivers a fast OER kinetics (32.1 mV dec−1) along with a low overpotential of 215 mV@10 mA cm−2. Benefiting from the synergistic effect of high conductivity, large specific surface area, and favorable OER kinetics, the catalyst only requires a low cell voltage of 1.456 V to achieve 20 mA cm−2 for overall water splitting, superior to that of a commercial RuO2ǁPt/C catalyst. [ABSTRACT FROM AUTHOR]

Ischemia/reperfusion (I/R) is a pathological process that causes severe damage. Propofol is known to alleviate I/R-related injury; however, the exact function and underlying mechanisms are not fully understood. Using an oxygen glucose deprivation/re-oxygenation (OGD/R) method, an in vitro I/R injury model was induced. The cell viability and the level of Fe2+, glutathione synthetase (GSH), and malondialdehyde (MDA) were evaluated using kits. Luciferase reporter gene assay, chromatin immunoprecipitation, and RNA immunoprecipitation (RIP) were used to verify the interaction between molecules. The m6A level of BECN1 mRNA was determined through methylated RIP. Propofol-treated OGD/R models showed reduced levels of Fe2+ and MDA, while the cell viability and the level of GSH increased. Propofol inhibited ferroptosis by down-regulating HIF-1α in OGD/R-treated HT22 cells. HIF-1α is bound to the promoter region of YTHDF1 to promote its transcription, and YTHDF1 promoted ferroptosis by stabilizing the mRNA of BECN1. The suppressive effect of propofol on OGD/R-induced ferroptosis was reversed by the overexpression of YTHDF1. Our study revealed that the HIF-1α/YTHDF1/BECN1 axis in OGD/R-treated HT22 cells promotes ferroptosis, and administration of propofol can inhibit this axis to avoid cell death. This study provides a novel insight for the neuroprotective function of propofol. [ABSTRACT FROM AUTHOR]

Rational engineering of non-noble metal catalysts with exposed highly active facets for water splitting is desirable yet remains greatly challenging. Herein, we report a doping-induced facet transformation strategy to prepare single-crystalline cobalt carbonate hydroxide hydrate (CCOH) nanowires with high oxygen evolution reaction (OER) activity. Specifically, Cu doping induces the CCOH nanowires to grow along the (020) direction, whereas nanowires without Cu dopant grow along the (121) direction. Density functional theory calculations reveal that compared with the (121) surface, the (020) surface of CCOH has higher intrinsic OER activity due to different atomic arrangements and coordination. As a result, the Cu-doped (020)-faceted CCOH nanowire arrays exhibit outstanding OER performances with a low overpotential of 210 mV at 10 mA cm−2 and a Tafel slope of 67 mV dec−1 in alkaline medium, as well as extremely long-term durability over 36 h. Our findings demonstrate that doping-induced facet engineering is an effective strategy to design and develop highly active catalysts. [ABSTRACT FROM AUTHOR]