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Summary: Facile synthesis of highly efficient and low‐cost electrocatalyst for oxygen evolution reaction (OER) is important for large‐scale hydrogen production. Herein, nickel hydroxide/reduced graphene oxide (Ni(OH)2/rGO) composite thin film was fabricated using dip‐coating followed by electrodeposition method on Ni foam substrate at room temperature. The deposited composite film shows amorphous nature with ultra‐thin Ni(OH)2 nanosheets vertically coated on rGO surface, which provides large electrochemical surface area and abundant catalytically active sites. It exhibits a low overpotential of 260 mV @10 mA cm−2 as compared to the pristine electrodes and excellent long‐term stability up to 20 hours in 1 M KOH solution. The electrochemical active surface area and Tafel slope of the composite electrode are 20.2 mF cm−2 and 35 mV dec−1, respectively. The superior water oxidation performance is a result of high catalytically active sites and improved conductivity of the composite electrode. [ABSTRACT FROM AUTHOR]

A simple, economical successive ionic layer adsorption and reaction (SILAR) method has been used for synthesizing 1, 2 and 3 at.% copper‐doped strontium hydroxide over a stainless‐steel (SS) substrate. X‐ray diffraction reveals the orthorhombic crystal structure of polycrystalline Cu‐doped Sr(OH)2. FTIR and Raman analyses explore the chemical bond analysis of the active material. The morphology of the Cu‐doped Sr(OH)2 was analyzed by using SEM. This shows novel hierarchical‐branched tuberose with flakes. The energy‐dispersive X‐ray spectroscopy (EDAX) also confirms the doping of Cu into Sr(OH)2. The electrochemical properties have been investigated by using cyclic voltammetry (CV) and galvanostatic charge−discharge measurements. It has been perceived that doping clearly affects the supercapacitive behavior. The specific capacity of the 3 at.% Cu‐doped Sr(OH)2 film electrode exhibits a maximum specific capacity of 817 C g−1 at 0.4 mA cm−1 in 1 M Na2SO4 electrolyte, but has a low cycle stability. The 2 at.% Cu‐doped sample shows high cycle stability by retrieving 71 % of its capacity after 5000 cycles. The relationship between the doping concentration and supercapacitive behavior has also been discussed. The good capacitive behavior and cycle stability of the Cu‐doped Sr(OH)2 gives the new perspective for the flexible electrode material, which can be used in the near future as an energy storage material. ′Caps off: Tuberose with a flake‐like structure and Cu‐doped Sr(OH)2 is fabricated by using a low‐cost wet chemical SILAR technique. The unique morphology and superior specific capacity is demonstrated. The influence of Cu on the morphology as well as the supercapacitive behavior is investigated. [ABSTRACT FROM AUTHOR]

Simple and cost effective ‘dip and dry’ approach has been demonstrated for the coating of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) onto multiwalled carbon nanotubes (MWNCTs) thin film, films are characterized by different techniques such as X-ray diffraction, Fourier transform infrared spectroscopy and scanning and transmission electron microscopy techniques where uniform coating of amorphous PEDOT:PSS on MWCNTs has been confirmed. The electrochemical performance of the PEDOT:PSS/MWCNTs electrode has been evaluated by using cyclic voltammetry and galvanostatic charge-discharge techniques. The specific capacitance of 235 Fg − 1 at 5 mVs − 1 has been achieved within 0 to 0.9 V potential range in 1 M aqueous H 2 SO 4 electrolyte. Furthermore, electrochemical impedance spectroscopy (EIS) analysis showed the lower equivalent series resistance and excellent frequency response of PEDOT:PSS/MWCNTs electrode material. [ABSTRACT FROM AUTHOR]

ZnFe 2 O 4 thin film has been synthesized by a simple and low cost successive ionic layer adsorption and reaction (SILAR) method without the use of surfactant or template. The nanoplate composed of nanoparticles with porous surface morphology has been revealed which is beneficial towards supercapacitor application. Formed ZnFe 2 O 4 thin film has been tested as an electrode material for supercapacitor through electrochemical analysis. First attempt for SILAR synthesized ZnFe 2 O 4 thin film exhibited a specific capacitance of 471 Fg −1 at a scan rate of 5 mVs −1 in 1 M NaOH aqueous solution. Further, ZnFe 2 O 4 solid-state symmetric (SSS) supercapacitor device demonstrated voltage window of 1.0 V with specific capacitance of 32 Fg −1 , energy density of 4.47 Whkg −1 and power density of 277 Wkg −1 at 1 Ag −1 current density. Such high performance capacitive behavior indicates ZnFe 2 O 4 thin film is promising and low cost electrode material towards energy storage devices for various portable electronic systems. [ABSTRACT FROM AUTHOR]

Thin films of zinc oxide (ZnO) nanodots decorated onto the multiwalled carbon nanotubes (MWNTs) were prepared by simple and inexpensive two-step chemical method which includes ‘dip and dry’ process followed by successive ionic layer adsorption and reaction (SILAR) method. The as-prepared ZnO/MWNTs (ZCN) composite films were characterized with different physicochemical techniques. The surface morphological analysis shows that the ZnO nanodots with average size less than 15 nm get uniformly decorated onto the MWNT walls. Furthermore, the electrochemical analysis carried out for ZCN composites suggests that these are the efficient electrodes for electrochemical charge-storage applications. [ABSTRACT FROM AUTHOR]

Abstract: We report on the synthesis of nanocrystalline titanium dioxide thin films and powders by chemical and electrochemical deposition methods. Both methods are simple, inexpensive and suitable for large-scale production. Air-annealing of the films and powders at T =500 °C leads to densely packed nanometer sized anatase TiO2 particles. The obtained layers are characterized by different methods such as: X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Titanium dioxide TiO2 (anatase) phase with (101) preferred orientation has been obtained for the films deposited on glass; indium doped tin oxide (ITO) and quartz substrates. The powder obtained as the byproduct consists of TiO2 with anatase-phase as well. To cite this article: B. R. Sankapal et al., C. R. Chimie 9 (2006) . [Copyright &y& Elsevier]

Abstract: The growth of AgI (silver iodide) thin films has been performed in aqueous medium using simple chemical method at room temperature (25°C). Silver nitrate and potassium iodide have been used as source materials. Thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), surface photovoltage (SPV) and optical absorption spectroscopy. Glass and indium doped tin oxide (ITO) coated glass was used as substrates. The thin films were surface homogeneous with mixed β and γ-phases with surface roughness value of 21nm. Optical transmission on glass exceeds 80% for 150nm thick film with the direct band gap value of 2.85eV. The change in crystal phases after transition temperature is studied by SPV measurements. [ABSTRACT FROM AUTHOR]

Mixed phase of iron telluride based thin films consisting of nanopebbles has been grown successfully over conducting stainless steel (SS) substrate through successive ionic layer adsorption reaction (SILAR) process. Crystal structural and elemental states through XPS revealed clear indication of FeTe: Fe 2 TeO 5 mixed phase growth and well supported through FTIR studies. Agglomeration of embedded quantum dots forming nanopebbles like surface architecture resulting in enhanced hydrophilic nature evident through contact angle and higher surface roughness by atomic force micrographs found beneficial as more electroactive surface area for electrolyte ions to interact. This helped to achieve a significant specific capacitance of 591 F/g (166 mF/cm2) @3 mV/s potential scan rate and, 107 F/g (30 mF/cm2) @0.4 mA/cm2 in NaCl electrolyte. Performed electrochemical impedance spectroscopy (EIS) studies explored clear insight of the solution and charge transfer resistances, and relaxation time constant. Iron telluride based thin film clearly demonstrates very high value of pseudo capacitive contribution than the electric double layer due to the intrinsic pseudocapacitive behavior of mixed phase. [Display omitted] • First report on iron telluride based (FeTe: Fe 2 TeO 5) thin film synthesis using simple SILAR method and successfully employed as supercapacitor electrode. • Nanopebbles embedded with quantum dots agglomeration responsible for more electrochemical active sites. • Notable specific capacitance of 591 F/g (426 C/g or 166 mF/g) at 3 mV/s by CV and 107 F/g (30 mF/cm2) at 0.4 mA/cm2 by GCD studies. • Enhanced inner (pseudo q p) charge storage contributions than outer (EDLC q d l ). [ABSTRACT FROM AUTHOR]

Design of nanostructured surface architecture is currently playing a vital role to enhance the energy storage capability of electrode materials and opening up a new era for future technologies through electrochemical supercapacitors. Present effort portrays the growth of nanostructured bismuth vanadate (BiVO 4) as an active electrode for supercapacitor application by using ease and industry scalable successive ionic layer adsorption and reaction (SILAR) method. Structural analysis reveals the development of orthorhombic structured BiVO 4 with spongy nano-pebbles like surface architecture. Synthesized BiVO 4 electrode yields remarkable capacitance of 707 F/g @3 mV/s scan rate. Faradaic and capacitive type contributions have been evaluated for in-depth understanding along with the estimation of electrochemical active surface area. Electrochemical impedance spectroscopy (EIS) analysis of BiVO 4 electrode exhibits 5.723 and 0.89 Ω cm2 values of series and charge transfer resistances, respectively. Interestingly, BiVO 4 electrode delivers outstanding capacitive retention of 102% even at 3500 cycles, indicating its potential candidature for the advancement in high capability supercapacitors with excellent stability for the future technologies. [Display omitted] • Bismuth vanadate (BiVO 4) thin film consisting of sponge-like nano-pebbles synthesized by the SILAR-chemical route. • BiVO 4 demonstrated the highest specific capacitance of 707 F/g at a 3 mV/s scan rate. • Outstanding electrochemical capacitive retention of 102% @ 3500 cycles. [ABSTRACT FROM AUTHOR]

Graphical abstract An investigation of field emission studies of solution processed MWCNTs, MoS 2 and MoS 2 anchored MWCNTs thin films grown on low cost stainless steel substrates have been performed. Drastic diminishing in turn-on field value has been obtained for MWCNTs/MoS 2 nanocomposite compared to bare MWCNTs and MoS 2. Present investigations open path for the development of low temperature solution processed MWCNTs/MoS 2 field emitter for nanoelectronics devices. Highlights • Synthesis of MoS 2 nanoflakes, MWCNTs, MWCNTs/MoS 2 nanocomposite. • Observation of low turn-on field. • Stable emission current. Abstract An investigation of field emission on solution processed MWCNTs, MoS 2 and MoS 2 anchored MWCNTs thin films on low cost stainless steel substrates have been performed. Decorative morphology of MoS 2 nanoflakes over MWCNTs interconnected high surface area nanonetwork supports the active path for the application of field emission. Drastic diminishing in turn-on field value has been obtained for MWCNTs/MoS 2 nanocomposite compared to bare MWCNTs and MoS 2. Hence, present investigation opens path for the development of low-temperature solution processed MWCNTs/MoS 2 thin film in the field of nanoelectronics and the used process can be integrated for large scale. [ABSTRACT FROM AUTHOR]

Low-cost, easily synthesized, and high energy/power density embedded stable supercapacitive electrodes are the demands for today’s renewable and green energy dependent generation. In search of that, Bi 2 S 3 :PbS solid solution in thin film form has been synthesized by modest successive ionic layer adsorption and reaction (SILAR) method and characterized by XRD, FESEM, and HRTEM. Formation of solid solution in the form of nanoparticles gilded thin film exposes sufficient electroactive cavities for electroactive ions to incorporate. The composite exhibited excellent specific capacitance of 402.4 F/g at current density of 1 mA/cm 2 with modest charge-discharge cycles. In terms of energy storage, it exhibited maximum specific power of 20.1 Wh/kg with accepting specific power of 1.2 kW/kg. The combination of two nanoparticles in nanocomposites thin film supplies new tactic for energy storage applications. [ABSTRACT FROM AUTHOR]

Complex nanostructured morphology of V 2 O 5 has been grown on pliable stainless steel substrate (SS) through simple and inexpensive chemical bath deposition (CBD) for all-solid state flexible supercapacitor (SC). The structure and morphology of the synthesized V 2 O 5 thin films revealed the formation of intermixed flakes. High specific capacitance of 735 F g −1 (at scan rate of 1 mV s −1 ) of V 2 O 5 through liquid configuration motivated us to form complete flexible all-solid state symmetric supercapacitor (FASC) device. Remarkable specific capacitance of 358 F g− 1 . With 1.8 V wide potential window and high value of capacitive retention of 88% over 1000 cycles has been achieved for FASC. Furthermore, the origin of capacitive behavior from dual contributions of surface-controlled and diffusion-controlled charge components has been evaluated to identify the dominating nature in electrochemical reactions. As practical applicability, pliability of electrode has been tested at 175° bending angle along with the integration to large scale electrode dimension (11 ×4 cm 2 ). [ABSTRACT FROM AUTHOR]

Cadmium sulfide (CdS) thin film consisting of nanowires over a flat CdS thin film were synthesized by depositing cadmium hydroxide [Cd(OH) 2 ] nanowires (NW) bundles, followed by conversion to sulfide phase by using ion exchange route at room temperature (300 K) based on negative free energy of formation. The influence of post annealing treatment on as-deposited CdS NW films has been studied in the temperature range 423–523 K through the observation of nanowires alignments. The annealing effect on the intrinsic properties have been studied in relation with the crystallites sizes, micro strain, dislocation density and optical band gap of the deposited films. Furthermore, the behavior of inter- and intramolecular hydroxide ion (OH − ) has been investigated from FTIR analysis. Additionally, the effects of post annealing on photovoltaic device performance has been scrutinized and the obtained results were correlated with structural and optical properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • The state of art to grow silver selenide (Ag 2 Se) nanostructured thin film with the aid of simple, well controlled and room temperature successive ionic layer adsorption and reaction (SILAR) onto stainless steel substrate. • First report to use silver selenide (Ag 2 Se) for supercapacitor application. • Correlation between surface wettability, surface morphology with electrochemical supercapacitive parameters. • CV graphs were used to study surface-induced capacitance, diffusion-controlled processes, and stability. • EIS analysis was done to understand the electrochemical resistances, phase angle, and diffusion coefficient estimation in Na 2 SO 3 electrolyte. Well controlled growth of pseudocapacitive nanostructured silver selenide (Ag 2 Se) thin film has been achieved through simple, less expensive, room temperature and industry scalable successive ionic layer adsorption and reaction (SILAR) method onto stainless steel substrate to use as electrode material for supercapacitor application as the first report. X-ray photoelectron spectroscopy studies confirmed the formation of Ag 2 Se. Orthorhombic structure of grown Ag 2 Se thin film exhibits hydrophilic nature in aqueous Na 2 SO 3 electrolyte yielding specific capacitance of 112.45 F/g @ 10 mV/s scan rate studied through cyclic voltammetry (CV) and 115.99 F/g @ 0.8 A/g by galvanostatic charge discharge through electrochemical studies. Interestingly Ag 2 Se electrode exhibits 85.10 % capacitive retention after 2000 CV cycles. Origin of net-charge stored at the electrode–electrolyte interface has been well understood from surface induced capacitive and diffusion-controlled mechanisms. Low equivalent series resistance (ESR) value of 0.06 Ω was determined by the plot of iR drop vs. current density exhibiting high-power burst electrode material. [ABSTRACT FROM AUTHOR]

• The Cu(OH)2@Cd(OH)2 core-shell nanowire structure via cation ion exchange. • Cu(OH)2@Cd(OH)2 core-shell nanowire structure showed good capacitive behavior. • Cu(OH)2@Cd(OH)2 possess specific capacitance of 374 Fg−1. The Cu(OH) 2 @Cd(OH) 2 core-shell nanowire structure have been successfully synthesized by facile cation exchange reaction based on negative free energy of formation through topotactical transformation from their cadmium hydroxide to copper hydroxide. The encapsulation of the copper into the cadmium hydroxide nanowires was confirmed by X-ray diffraction studies, elemental analysis and Fourier transform infrared spectroscopy. Electrochemical study shows that Cu(OH) 2 @Cd(OH) 2 core-shell nanowire structure possess high specific capacitance of 374 Fg−1 in an aqueous 1 M NaOH electrolyte. Present work demonstrates Cu(OH) 2 @Cd(OH) 2 nanowires, synthesis and application as supercapacitive electrode. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesized CdS thin films revealed mixed cubic and hexagonal phases. • Metal free azo dyes optimized by DFT used for sensitization of CdS NWs. • Azo dye D2 has shown 5 fold increase in solar to electric conversion compared to pristine CdS NWs. • Explored effect of cosensitization of natural dye Betanin on solar to electric conversion. Herein, as-synthesized azo dye (E)-2-isopropyl-5-methyl-4-((4-(4-nitrophenyl) thiazol-2-yl) diazenyl) phenol (D2) has been anchored on a high surface area one dimensional CdS nanowires (NWs) in thin film form. CdS nanowires have been grown through Cd(OH) 2 template formation followed by conversion to CdS by ion-exchange route. The light-electricity conversion efficiency of the CdS-Azo dye-based solar cell has shown about 5-fold remarkable surge (0.159%) compared to the bare CdS (0.03%) with I 3 −/I− redox mediator under standard AM 1.5 illumination (100 mW cm−2). Albeit, the DFT studies revealed a higher band gap for pristine D2, alluringly it has depicted higher light-electricity conversion efficiency among the fabricated thin film solar cells after sensitization. The relative increase in sensitivity after sensitization is attributable to facile dye regeneration. Furthermore, after the co-sensitization of CdS thin film with equimolar cocktails of as-synthesized dyes and a natural dye Betanin (Bn), less efficiency was depicted ascribable to plausible dye aggregation upon blending. [ABSTRACT FROM AUTHOR]

Abstract Thin film consisting of hierarchical cadmium oxide nanonecklaces has been synthesized through room temperature chemically deposited cadmium hydroxide nanowires as template followed by air annealing. Formation of thin film has been confirmed with aid of structural, surface morphological, valence state and optical, studies performed by X-ray diffraction, Raman analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, and UV–visible spectroscopy. Air annealing at 330 °C has enhanced the photo electrochemical power conversion efficiency of the CdO as photoanode to 0.21% configured through platinum as counter electrode and polyiodide as a liquid electrolyte. Complete device performance have been correlated through rate of recombination, and electron life time. The schematic energy band alignment also has been comprehended herein. Graphical abstract Image 1 Highlights • CdO nanonecklace has been synthesis by simple chemical method. • CdO nanonecklace has been fabricated by annealing cadmium hydroxide nanowires. • Porous CdO nanonecklace shows power conversion efficiency of 0.21% with fill factor of 40.94%. [ABSTRACT FROM AUTHOR]

Increasing energy storage capacity through the use of novel nano-ranged structures is advantageous for the generation of high-rate performing supercapacitors. Designing metal electrodes that are easily available on earth, cheap, and have better charge transfer characteristics with high stability is still challenging. Current article assesses the first study to explore the synthesis of Mn nanoparticles with spongy nano flakes-like surface architecture using simple, room temperature electroless route to serve as an active electrode for supercapacitive energy storage device. Interestingly, Mn thin film electrode attained a capacitance of 663 F g−1 with a cyclic retention of 103% at 5000 cycles. Designed bendable solid-state symmetric device exhibits an extraordinary specific power of 1.2 kW kg−1 and an exceptional deformation endurance (96% at 170°), indicating its suitability for advanced flexible energy storage applications. • Simple, time-efficient, and economical electroless route over stainless (SS) substrate. • Spongy nano flakes-like surface architecture with high specific capacitance of 663 F g−1. • A complete solid-state device fabrication from flexible PVA-KOH electrolyte membrane. • Notable energy density (27.8 Wh kg−1) at 1.2 kW kg−1 and long cycle life. • Phenomenal mechanical flexibility (96% at 170° of bending). [ABSTRACT FROM AUTHOR]

CdO nanonecklace like structure with interconnected nanobeads were produced by air annealed Cd(OH) 2 nanowire structure thin film at 290 °C. Simple and low cost chemical route has been successfully employed for the synthesis of Cd(OH) 2 nanowires on fluorine doped tin oxide (FTO) coated glass substrates at room temperature (27 °C). Structural analysis confirmed the conversion of hydroxide phase to the oxide phase by annealing which also leads to change in optical band gap from 3.5 to 2.34 eV. The necklace like nanostructure represent unique surface morphology which can be emerged as a potential candidate towards wide range of applications in different fields of nanotechnology such as solar cell, gas sensor, supercapacitor and photo-catalyst. [ABSTRACT FROM AUTHOR]

Abstract: Simple wet chemically grown ZnO with interconnected nanoparticles network having cactus morphology was successfully demonstrated as a photoanode towards dye sensitized solar cell applications with two different dyes, namely, D149 and N719 with the device efficiencies of 3.43% and 3.09%, respectively. [Copyright &y& Elsevier]