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In everyday life, superior lithium-ion batteries (LIBs), with fast charging ability, have become valuable assets. The LIB performance of an anode composite copper cobalt tin sulphide (Cu2CoSnS4; CCTS) electrode, which was fabricated using a simple and easy hydrothermal method, was investigated. The electrochemical charge storage performance of the CCTS anode demonstrated sustainability, high-rate capability and efficiency. The CCTS anode exhibited a first discharge capacity of 914.5 mA h g−1 and an average specific capacity of 198.7 mA h g−1 in consecutive cycles at a current density of 0.1 A g−1. It had a capacity retention of ∼62.0% and a coulombic efficiency of more than 83% after over 100 cycles, demonstrating its excellent cycling performance and reversibility. It can be an alternative anode to other established electrode materials for real battery applications. [ABSTRACT FROM AUTHOR]

Summary: The photoelectrochemical (PEC) properties of nanoflake‐like cadmium sulfide (CdS) sensitized zinc stannate (Zn2SnO4) heterostructure prepared by spray pyrolysis technique and chemical bath deposition (CBD) are investigated in detail. The crystallinity and surface morphology of the Zn2SnO4 and CdS films are evaluated by X‐ray diffraction (XRD), and scanning electron microscope, whereas its optical properties are analyzed by UV‐VIS spectroscopy. Zn2SnO4 exhibits uniform granular structure and it has well defined reflection along (311) plane revealing inverse‐spinel cubic structure. Zn2SnO4 showed band gap of 3.8 eV, it is well agreeing with the literature. The CdS films fabricated by CBD exhibited nanoflake‐like structures. The XRD pattern of the CdS‐sensitized Zn2SnO4 heterostructure exhibits a mixed phases of the zinc stannate and CdS. The PEC properties of the Zn2SnO4‐CdS heterojunction are studied by using a three‐electrode electrochemical cell in a Na2S electrolyte. Zn2SnO4‐CdS system has shown 0.8 mA/cm2 photo‐current density whereas with increasing CdS layer thickness it has shown marginal enhancement up to 2.2 mA/cm2. The stability of the Zn2SnO4‐CdS heterojunction is outstanding up to 300 s. The results demonstrate that Zn2SnO4‐CdS heterojunction could be a potential material in PEC and solar cell applications. [ABSTRACT FROM AUTHOR]

Summary: Urea oxidation reaction (UOR) assisted water‐splitting is a promising approach for effective treatment of urea‐rich waste‐water at the anode and parallelly generate green‐hydrogen (H2) energy at the cathode via hydrogen evolution reaction (HER). However, facile designing and fabricating robust and cheap electrodes derived from earth‐abundant materials is a great challenge. This work reports the synthesis of vanadium sulfide (VS2) micro‐flowered structure via solvent‐assisted hydrothermal method using ethylene glycol as an additive in the aqueous‐based reaction medium, which has imparted a significant effect on the morphology and the crystallinity of the VS2. In addition, in contrast to the VS2 electrode fabricated in a pure aqueous medium, the ethylene glycol mediated VS2 electrode upon coupling as a cathode and anode in an HER||UOR vs reversible hydrogen electrode (RHE)‐based three‐electrode configuration demonstrates a significantly reduced overall urea decomposition potential of 1.38 V at a current density of 10 mA cm−2 as compared to the conventional water‐splitting of 1.75 V vs RHE. The obtained high‐performance electrocatalytic activity on UOR and HER can be ascribed to the influence of ethylene glycol solvent, particularly on VS2 growth, morphology, and crystallinity, favoring the formation of abundant catalytic sites with facile electrolyte diffusion and electrolysis. [ABSTRACT FROM AUTHOR]

Summary: Replacing oxygen in an oxide‐based material with sulfur can produce improved flexibility and more efficient electron transport in its structure leading to enhanced electrical performance. Herein, facile template‐free growth of free‐standing cobalt (II, III) oxide (Co3O4) on Ni foam via a mild hydrothermal technique followed by its transformation to cobalt (II, III) sulfide (Co3S4) via an ion‐exchange is reported. The microstructural morphology, phase, and porosity of the prepared Co3O4 and Co3S4 are characterized by FESEM, XRD, Raman, XPS, TEM, and BET analyses. The electrochemical performance of the Co3S4 film with a microporous morphology is considerably superior to that of Co3O4, exhibiting a high specific capacitance of 1604 F g−1 (905 F g−1 for Co3O4), the excellent restorative ability of ~99% at 1 A g−1 (~96% for Co3O4), and good retention of 98% at 10 A g−1 (~70% for Co3O4). The Co3S4 electrode shows excellent capacitance endurance even after 10 000 charge/discharge cycles and a high energy density of 128.32 Wh kg−1 at 0.72 kW kg−1. A fabricated symmetric Co3S4 supercapacitor device also reveals superior charge/discharge, restorative, and retention performances compared to a Co3O4 one. The excellent supercapacitive performance of phase‐transformed Co3S4 electrode is due its large electrochemically active surface area along with synergetic effect of small charge transfer resistance and high relative diffusion coefficient. [ABSTRACT FROM AUTHOR]

Summary: Bimetallic electrocatalysts have attracted great importance and they have proved themselves as a promising strategy for high‐performance electrocatalysis. They offer the synergetic effect between different elements and structural modification to enhance the electrochemical surface area (ECSA) and conductivity. In this study, efficient nonprecious bimetallic electrocatalysts of Mn1−xCux oxide (0.15 ≤ x ≤ 0.75) have been synthesized using a simple and cost‐effective electrodeposition technique. The effect of compositional ratios between Mn and Cu on the electrochemical properties has been systematically investigated. The dramatic change of morphology upon composition variation suggests the alteration of ECSA, which is an important factor for electrocatalysis. The optimized Mn0.50Cu0.50 catalyst exhibits a low overpotential of 291 mV to reach a current density of 10 mA cm−2 with a low Tafel slope of 54.6 mV dec−1. It showed ultra‐high stability at a very high current density of 500 mA cm−2 in alkaline media. The enhanced catalytic activity of Mn0.50Cu0.50 electrocatalyst is associated with the enhanced ECSA, formation of porous morphology, which facilitates the diffusion coefficient, and enhanced electronic conductivity. Overall, Mn‐Cu is one of the best capable electrocatalysts for oxygen evolution reaction, which confirmed abundant potential in realistic applications. [ABSTRACT FROM AUTHOR]

Summary: We report an effective strategy generally applicable towards improving Li‐ion battery performance with insulating metal oxide‐based anode materials. We fabricated density‐modulated multilayered homo‐junction tungsten oxide (WOx) films as anode materials for Li‐ion batteries, in which high‐ and low‐density thin layers were alternately deposited on Cu current collectors using radio frequency magnetron sputtering. The performance of the battery with multilayered WOx was systematically optimized by changing the number of layers and deposition order. A 4‐layer density‐modulated WOx anode with a low density on top WOx layer showed superior performance with a high reversible capacity of 508 mAh g−1 after 200 cycles at a current density of 0.2 A g−1. Moreover, it provided a reversible capacity of 150 mAh g−1 and good coulombic efficiency of 93.7% after 1000 cycles at a high current density of 2 A g−1 and showed excellent rate capability and cycling stability. The observed outstanding battery performance of the density‐modulated multilayer WOx anode can be attributed to its controlled mass loading, optimized charge‐transfer kinetics, and favourable morphology. [ABSTRACT FROM AUTHOR]

The exploration of memtransistors as a combination of a memristor and a transistor has recently attracted intensive attention because it offers a promising candidate for next‐generation multilevel nonvolatile memories and synaptic devices. However, the present state‐of‐the‐art memtransistors, which are based on a single material, such as MoS2 or perovskite, exhibit a relatively low switching ratio, require extremely high electric fields to modulate bistable resistance states and do not perform multifunctional operations. Here, the realization of an electrically and optically controllable p–n junction memtransistor using an Al2O3 encapsulated 2D Te/ReS2 van der Waals heterostructure is reported. The hybrid memtransistor shows a reversible bipolar resistance switching behavior between a low resistance state and a high resistance state with a high switching ratio up to 106 at a low operating voltage (<10 V), high cycling endurance, and long retention time. Moreover, multiple resistance states are achieved by applying different bias voltages, gate voltages, or light powers. In addition, logical operations, including the inverter and AND/OR gates, and synaptic activities are performed by controlling the optical and electrical inputs. The work offers a novel strategy for the reliable fabrication of p–n junction memtransistors for multifunctional devices and neuromorphic applications. [ABSTRACT FROM AUTHOR]