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Self-assembled CuO nanosheet bundles are fabricated on stainless steelviachemical bath deposition and optimized for efficient electrocatalysis.

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This work reports on the concurrent electrochemical energy storage and conversion characteristics of granular copper oxide electrode films prepared using reactive radio-frequency magnetron sputtering at room temperature under different oxygen environments. The obtained films are characterized in terms of their structural, morphological, and compositional properties. X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscope studies reveal that granular, single-phase Cu2O and CuO can be obtained by controlling the oxygen flow rate. The electrochemical energy storage properties of the films are investigated by carrying out cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy tests. The electrochemical analysis reveals that the Cu2O and CuO electrodes have high specific capacitances of 215 and 272 F/g in 6 M KOH solution with a capacity retention of about 80% and 85% after 3000 cycles, respectively. Cyclic voltammetry and chronoamperometry are used to study the electrochemical energy conversion properties of the films via methanol electro-oxidation. The results show that the Cu2O and CuO electrodes are electro-catalytically active and highly stable.

An efficient and sustainable gas diffusible OER anode toward industrial alkaline water-splitting is fabricated by simply immersing Ni foam in ethanolic FeCl3 etchant, which produces a microporous Ni backbone decorated with nanocatalysts.

A supercapacitor is well recognized as one of emerging energy sources for powering electronic devices in our daily life. Although various kind of supercapacitors have been designed and demonstrated, their market aspect could become advanced if the utilisation of other physicochemical properties (e.g. optical) is incorporated in the electrode. Herein, we present an electrochromic supercapacitor (smart supercapacitor) based on a nanoflake NiMoO 4 thin film which is fabricated using a facile and well-controlled successive ionic layer adsorption and reaction (SILAR) technique. The polycrystalline nanoflake NiMoO 4 electrode exhibits a large electrochemically active surface area of ~ 96.3 cm 2. Its nanoporous architecture provides an easy pathway for the intercalation and de-intercalation of ions. The nanoflake NiMoO 4 electrode is dark-brown in the charged state and becomes transparent in the discharged state with a high optical modulation of 57 %. The electrode shows a high specific capacity of 1853 Fg-1 at a current rate of 1Ag-1 with a good coloration efficiency of 31.44 cm 2 /C. Dynamic visual information is obtained when the electrode is charged at different potentials, reflecting the level of energy storage in the device. The device retains 65% capacity after 2500 charge-discharge *Manuscript Click here to view linked References 2 cycles compared with its initial capacity. The excellent performance of the nanoflake NiMoO 4 based smart supercapacitor is associated with the synergetic effect of nanoporous morphology with a large electrochemically active surface area and desired chemical composition for redox reaction.

As an energy source, hydrogen has outstanding properties, such as zero carbon emission, high conversion efficiency, and recyclability. [1] Moreover, it is the cleanest primary energy resource on earth and is a candidate for replacing fossil fuels. Water, which is the most abundant source of hydrogen, can be used for producing hydrogen if the strong bond between hydrogen and oxygen can be broken. Water electrolysis is a process in To generate hydrogen, which is a clean energy carrier, a combination of electrolysis and renewable energy sources is desirable. In particular, for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in electrolysis, it is necessary to develop nonprecious, efficient, and durable catalysts. A robust nonprecious copper-iron (CuFe) bimetallic composite is reported that can be used as a highly efficient bifunctional catalyst for overall water splitting in an alkaline medium. The catalyst exhibits outstanding OER and HER activity, and very low OER and HER overpotentials (218 and 158 mV, respectively) are necessary to attain a current density of 10 mA cm −2 . When used in a two-electrode water electrolyzer system for overall water splitting, it not only achieves high durability (even at a very high current density of 100 mA cm −2 ) but also reduces the potential required to split water into oxygen and hydrogen at 10 mA cm −2 to 1.64 V for 100 h of continuous operation.which water is split into oxygen and hydrogen, and technologies related to this process are attracting considerable attention for their potential use in the production of clean and environmentally friendly energy. [2] Electrochemical water splitting comprises two reactions: the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. [1] Of these, the OER is the main reaction because it involves complex electron-proton transfer that leads to sluggish kinetics and a high overpotential.In general, all electrocatalysts used for splitting water into oxygen and hydrogen require a high overpotential in addition to the ideal potential (note that the total reaction ideally requires a potential difference of 1.23 V to split water into oxygen and hydrogen). A major challenge is the fabrication of durable and efficient catalyst materials for the OER. [3] In addition, from the viewpoint of productivity and cost effectiveness, it is highly advantageous to fabricate bifunctional electrocatalysts that operate efficiently for both the OER and HER in the same aqueous alkaline or acidic media. [4] Recently, oxides, carbides, sulphides, phosphides, and layered double hydroxides (LDHs) of transition metals, as well as mixed-metal alloys, have been extensively investigated for use as electrocatalysts for the OER and HER. [5][6][7][8][9][10][11][12][13][14][15][16] Furthermore, several strategies have been employed to improve the electrocatalytic performance of current catalyst materials: morphology engineering, hybrid composite synthesis doping, etc. [5][6][7][8][9][10][11][12][1...

Zinc oxide (ZnO) thin films were electrodeposited from an aqueous zinc acetate solution onto fluorine-doped thin oxide (FTO) coated conducting glass substrates. The effect of organic surfactants like polyvinyl pyrrolidone (PVP), sodium dodecyl sulfate (SDS), polyethylene glycol (PEG), ethylene glycol (EG) and polyvinyl alcohol (PVA) on their structural, morphological, optical and photoelectrochemical properties was studied. The x-ray diffraction patterns revealed the formation of phase-pure ZnO thin films. The films deposited using organic surfactants exhibit different surface morphologies. It was observed that the organic surfactants play important roles in modifying the surface morphology and size of the crystallites. A compact granular morphology was observed for the ZnO samples grown without organic surfactants. The films exhibit nanoparticles of size 100-150 nm for PVP, EG and PVA mediated growth. The vertically aligned thin and compact hexagonal crystallites stem from the SDS, whereas microporous corrugated morphology is observed for PEG-mediated growth. All the samples exhibit room temperature photoluminescence (PL). Oxygen vacancies contribute to the active luminescent centers for the emission of green light in ZnO thin films. PL gets quenched for the SDS surfactant. All the samples were post-treated with ethanol to remove stray surfactant molecules. FTIR study was used to confirm the removal of adsorbed surfactant molecules from the samples. Moreover the samples are photoelectrochemically (PEC) active and exhibit the highest photocurrent of 231 µA, a photovoltage of 492 mV and 0.42 fill factor for the ZnO:SDS films.