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Water electrolysis is a highly efficient route to produce ideally clean H2 fuel with excellent energy conversion efficiency and high gravimetric energy density, without producing carbon traces, unlike steam methane reforming, and it resolves the issues of environmental contamination via replacing the conventional fossil fuel. Particular importance lies in the advancement of highly effective non-precious catalysts for the oxygen evolution reaction (OER). The electrocatalytic activity of an active catalyst mainly depends on the material conductivity, accessible catalytically active sites, and intrinsic OER reaction kinetics, which can be tuned via introducing N heteroatoms in the catalyst structure. Herein, the efficacious nitrogenation of CuS was accomplished, synthesized using a hydrothermal procedure, and characterized for its electrocatalytic activity towards OER. The nitrogen-doped CuO@CuS (N,CuO@CuS) electrocatalyst exhibited superior OER activity compared to pristine CuS (268 and 602 mV), achieving a low overpotential of 240 and 392 mV at a current density of 10 and 100 mA/cm2, respectively, ascribed to the favorable electronic structural modification triggered by nitrogen incorporation. The N,CuO@CuS also exhibits excellent endurance under varied current rates and a static potential response over 25 h with stability measured at 10 and 100 mA/cm2. [ABSTRACT FROM AUTHOR]

Double perovskites are known for their special structures which can be utilized as catalyst electrode materials for electrochemical water splitting to generate carbon-neutral hydrogen energy. In this work, we prepared lanthanide series metal-doped double perovskites at the M site such as M2NiMnO6 (where M = Eu, Gd, Tb) using the solid-state reaction method, and they were investigated for an oxygen evolution reaction (OER) study in an alkaline medium. It is revealed that the catalyst with a configuration of Tb2NiMnO6 has outstanding OER properties such as a low overpotential of 288 mV to achieve a current density of 10 mAcm−2, a lower Tafel slope of 38.76 mVdec−1, and a long cycling stability over 100 h of continuous operation. A-site doping causes an alteration in the oxidation or valence states of the NiMn cations, their porosity, and the oxygen vacancies. This is evidenced in terms of the Mn4+/Mn3+ ratio modifying electronic properties and the surface which facilitates the OER properties of the catalyst. This is discussed using electrochemical impedance spectroscopy (EIS) and electrochemical surface area (ECSA) of the catalysts. The proposed work is promising for the synthesis and utilization of future catalyst electrodes for high-performance electrochemical water splitting. [ABSTRACT FROM AUTHOR]

The doping of metal–organic frameworks (MOFs) with metal-ions has emerged as a powerful strategy for enhancing their catalytic performance. Doping allows for the tailoring of the electronic structure and local coordination environment of MOFs, thus imparting on them unique properties and enhanced functionalities. This frontier article discusses the impact of metal-ion doping on the electronic structure and local coordination of MOFs, highlighting the effects on their electrocatalytic properties in relation to the oxygen evolution reaction (OER). The fundamental mechanisms underlying these modifications are explored, while recent advances, challenges, and prospects in the field are discussed. In addition, experimental techniques that can be applied to tackle the realization of effective metal-ion doping of MOFs are also noted briefly. [ABSTRACT FROM AUTHOR]

Developing effective electrocatalysts for the oxygen evolution reaction (OER) that are highly efficient, abundantly available, inexpensive, and environmentally friendly is critical to improving the overall efficiency of water splitting and the large-scale development of water splitting technologies. We, herein, introduce a facile synthetic strategy for depositing the self-supported arrays of 1D-porous nanoneedles of a manganese cobalt oxide (Mn0.21Co2.79O4: MCO) thin film demonstrating an enhanced electrocatalytic activity for OER in an alkaline electrolyte. For this, an MCO film was synthesized via thermal treatment of a hydroxycarbonate film obtained from a hydrothermal route. The deposited films were characterized through scanning electron microscopy (SEM), X-ray diffractometry (XRD), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). In contrast to a similar 1D-array of a pristine Co3O4 (CO) nanoneedle film, the MCO film exhibits a remarkably enhanced electrocatalytic performance in the OER with an 85 mV lower overpotential for the benchmark current density of 10 mA cm−2. In addition, the MCO film also demonstrates long-term electrochemical stability for the OER in 1.0 M KOH aqueous electrolyte. [ABSTRACT FROM AUTHOR]

Operating temperatures considerably influence the energy storage mechanism of the anode of Li-ion batteries (LiBs). This effect must be comprehensively studied to facilitate the effective integration of LiBs in practical applications and battery management. In this study, we fabricated a novel anode material, i.e., copper–iron–tin–sulphide (Cu2FeSnS4, CFTS), and investigated the corresponding LiB performance at operating temperatures ranging from 10 °C to 55 °C. The CFTS anode exhibited a discharge capacity of 283.1 mA h g−1 at room temperature (25 °C), which stabilized to 174.0 mA h g−1 in repeated cycles tested at a current density of 0.1 A g−1. The discharge capacity at higher operating temperatures, such as 40 °C and 55 °C, is found to be 209.3 and 230.0 mA h g−1 respectively. In contrast, the discharge capacity decreased to 36.2 mA h g−1 when the temperature decreased to 10 °C. Electrothermal impedance spectroscopy was performed to determine the rate of chemical reactions, mobility of active species, and change in internal resistance at different operating temperatures. In terms of the cycle life, CFTS exhibited outstanding cycling stability for more than 500 charge/discharge cycles, with a 146% capacity retention and more than 80% coulombic efficiency. The electrochemical investigation revealed that the charge storage in the CFTS anode is attributable to capacitive-type and diffusion-controlled mechanisms. [ABSTRACT FROM AUTHOR]

Nanocrystals of CsPbBr3, a colloidal perovskite, are hybridized with silver nanoparticles (Ag NPs) and organic molecules (2,5‐diphenyloxazole, PPO) to improve X‐ray radioluminescence (RL). It is known that charge transfer from the PPO molecules to the CsPbBr3 nanocrystals enhances the RL efficiency of the CsPbBr3 nanocrystals. In this study, Ag NPs are introduced to further enhance the RL efficiency. The plasmonic process of the Ag NPs is activated by the PPO molecules, which contain X‐ray‐induced high‐energy charges. Subsequently, electric fields induced by the plasmonic process of the Ag NPs accelerate the charge transfer from the PPO molecules to the CsPbBr3 nanocrystals. The plasmonic effect of the Ag NPs is demonstrated by the full‐width half maximum (FWHM): the photoluminescence FWHM of the hybridized CsPbBr3 nanocrystals is reduced, whereas the RL FWHM remains unchanged. The Ag‐NP‐induced plasmonic effect improves the RL efficiency of the PPO‐decorated CsPbBr3 nanocrystals by ≈10%. The obtained results demonstrate that a plasmonic process can strengthen the RL of X‐ray scintillators for X‐ray detection and imaging. [ABSTRACT FROM AUTHOR]

This work reports a promising and sustainable method for valorization of abundantly available biomass feedstocks to overcome the thermodynamic high energy barrier of the OER via glucose electrolysis as a proxy anodic reaction, thereby driving the energy-efficient water splitting for green hydrogen generation. For this, a robust and efficient MIL-88B(Fe) based electrocatalyst is engineered via Cu doping. The ultrasonically prepared Cu-doped@ MIL-88B ink when drop-cast on nickel foam (NF) produces thin nano-porous 2D-sheet like films having a thickness of ca. 300 nm and demonstrates an excellent glucose oxidation reaction (GOR) with a lower potential of 1.35 V versus RHE at 10 mA cm−2. In addition, this electrode shows outstanding long-term electrochemical durability for 50 h and exhibits the maximum GOR current load of 350 mA cm−2 at 1.48 V vs. RHE, while the pristine MIL-88B based electrode exhibits a current load of only 180 mA cm−2 at the same potential bias. The remarkably higher current density after doping indicates an accelerated GOR, which is ascribed to the electronic structure modulation of the Fe nodes by Cu, thereby enhancing the active sites and charge transport characteristics of the frameworks. Most importantly, the MOF-based electrodes demonstrate the occurrence of the GOR prior to the OER at a large potential difference, hence assisting the energy-efficient water splitting for green hydrogen production. [ABSTRACT FROM AUTHOR]