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Three-dimensional Ni(OH)2/Ni foam electrodes with low cost are simply fabricated via a template-free growth method and employed as efficient anodes for a direct urea–hydrogen peroxide fuel cell (DUPFC). The surface morphologies of Ni(OH)2 catalysts on the electrodes can be easily controlled by altering the reaction temperatures. The nano-sheet (NS) Ni(OH)2/Ni foam electrode exhibits highest catalytic activity towards urea electro-oxidation among the four electrodes. The oxidation current density of the NS Ni(OH)2/Ni foam electrode reaches 337 mA cm−2 at 0.45 V (vs. Ag/AgCl) with a low onset oxidation potential in 0.6 mol L−1 urea and 5 mol L−1 KOH solutions. The DUPFC using NS Ni(OH)2/Ni foam anode shows an open circuit voltage of 0.86 V and high peak power density of 19.7 mW cm−2 and 28.8 mW cm−2 at 20 °C and 50 °C, respectively, which is much higher than the performance of direct urea fuel cells reported previously. The outstanding cell performance using a cheap NS Ni(OH)2/Ni foam anode indicates DUPFC is a promising new type of fuel cell. [ABSTRACT FROM AUTHOR]

Facile in-situ etching current collector prepares corresponding oxide or sulfide, which is directly used as faradic electrode material, supplying faster electron transportation and better connection, and thus displaying good supercapacitor performance. Here, we prepare Cu x S via etching copper foam and investigate the influence of etching time on the morphology and electrochemical performance. The results show that compared with the nano-rod Cu x S-1h/CF, nano-rod/wire Cu x S-2h/CF and block/nanorod Cu x S-4h/CF, the nano-rod/ribbon Cu x S-3h/CF electrode exhibits the highest specific capacity (448.8C g −1 at current density of 5 mA cm −2 ). We fabricate asymmetric supercapacitor based on Cu x S-3h/CF as positive electrode and AC as negative electrode to further evaluate the supercapacitor property and the device achieves a high energy density of 35 Wh kg −1 at power density of 266 W kg −1 . Furthermore, the outstanding cycling stability of 88% capacitance retention after 5000 charge-discharge cycles more enable the Cu x S-3h/CF become promising faradic electrode material. [ABSTRACT FROM AUTHOR]

Urea electro-oxidation reaction in alkaline medium is systematically analyzed by electrochemical impedance spectroscopy (EIS). The effects of polarization potential and KOH concentration on the impedance appearance are investigated. In the presence of urea, it is found that Nyquist plots exhibit two depressed semicircles, with one at higher frequencies stably locating in the first quadrant while the other’s location at lower frequencies varying between the first and second quadrant as the polarization potential changes. Results show both indirect and direct pathways proceed in urea electro-oxidation reaction. A mathematical model indicates the reverse loop in the Nyquist plots is attributed to CO 2 poisoning on the catalyst, which is also validated by the followed chronoamperometric method. Moreover, the rate determining steps of urea electro-oxidation reaction is dependent on KOH concentration. The EIS technique gives a new sight to interpret the poor stability of urea electro-oxidation on nickel catalyst, and thus helps to explore a CO 2 -insensitive catalyst. [ABSTRACT FROM AUTHOR]

Bimetallic nanoparticles with excellent activity and stability have been widely studied as H 2 O 2 electroreduction catalysts. Hereby, we have successfully found a green fabrication of high-stability Au-Pd nanoparticles directly supported on carbon fiber cloth (Au-Pd NPs/CFC) by using tobacco extract (nicotinamide) as a simple and ecofriendly reducing agent. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction analyses and high angle annular dark field scanning TEM are performed to characterize the morphology, composition and structure of the as-prepared electrode. Results show that alloy nanoparticles prepared with different mole ratios of HAuCl 4 /PdCl 2 mixtures in the wide range of 10–100 nm have a uniform distribution on every carbon fiber, presenting a regular circle shape. The 3D electrode is directly applied as the electrocatalyst for H 2 O 2 reduction in acid solution and does not introduce into any polymer binders. The catalytic performance is investigated by chronoamperometry and voltammetry, exhibiting desired catalytic performance and improved utilization than other representative nanomaterials recently reported. Furthermore, Au-Pd NPs do not aggregate after the whole test due to the effect of in-situ immobilization, showing a great significance for the application in fuel cells. A direct peroxide-peroxide fuel cell (DPPFC) using Au-Pd NPs/CFC cathode with Ni/Ni-foam anode acquires a maximum power density of 22.8 mW cm −2 . Electrochemical stability test through long-term potential cycles ( > 9 h) further confirms the high durability of the electrode. [ABSTRACT FROM AUTHOR]

A three-dimensional porous copper film is directly deposited on Cu foam by an electrodeposition method using hydrogen bubbles as dynamic template (denoted as Cu/Cu foam). Its electrocatalytic activity toward hydrazine electrooxidation is tested by linear sweep voltammetry, chronoamperometry and electrochemical impedance spectroscopy. Compared with Cu foam, hydrazine electrooxidation on the Cu/Cu foam electrode shows that the onset oxidation potential displays a ~100 mV negative shift, the current density at −0.6 V raises about 14 times, the apparent activation energy and the charge transfer resistance reduce significantly. The increasing electrocatalytic performance for hydrazine electrooxidation is mainly caused by the highly porous structure of the Cu/Cu foam electrode which can provide a large surface area and make electrolyte access the electrocatalyst surfaces more easily. Hydrazine electrooxidation on the Cu/Cu foam electrode proceeds through a near 4-electron process. [ABSTRACT FROM AUTHOR]

Organic polymer materials attract lots of attention as promising anode materials for lithium ion batteries (LIBs) due to the superior lithium ion storage capability and low cost. However, the inherent insulativity of the polymer anodes results in the unsatisfactory electrochemical performance. Herein, we design and construct a hierarchical flowers-like polyaniline-coated (PANI) pyromellitic dianhydride-based polyimide (PPI) composite (PANI-PPI-9). Benefiting from the core-shell structure, the PPI presents an improved electrochemical performance, especially the remarkable cycling life (503 mAh g−1 at 1.5 A g−1 after 2400 cycles). Ex-situ characterizations and kinetics analyses also verify that the PANI shell serves as the electronic transport highway without obstructing the Li storage of PPI. This work highlights the potential application of the multifarious polymer-based composite electrodes for the lithium ion batteries. • The structure construct strategy to design and prepare the PANI-coated PPI micron flowers. • Aromatic rings in the polyimide provide a large number of lithium storage sites. • The PANI-PPI-9 exhibits improved long-cycling and rate performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • SnS x /N-rGO-30 with rich heterostructures was prepared by a hydrothermal route. • Built-in electric field greatly accelerates the charge transfer and ion diffusion. • SnS x /N-rGO-30 shows high Li+ storage capacity of 1273 mAh g−1 at 0.1 A g−1. • SnS x /N-rGO-30 shows high Na+ storage capacity of 640 mAh g−1 at 0.1 A g−1. Metal sulfides have been broadly used as potential candidates in lithium-ion and sodium-ion batteries. However, they usually undergo huge volume expansion and shrinkage, inferior electronic conductivity and sluggish redox reaction kinetics. Construction of heterostructure turns out to be a successful route to accelerate the charge transfer kinetics. Herein, ultrafine SnS x nanoparticles (∼5 nm) with abundant heterostructure are anchored on N-doped graphene through a hydrothermal approach. The rich heterostructures and the interfacial effect induced by built-in electric field significantly accelerate the charge transport and ion diffusion. The SnS x /N-rGO-30 nanocomposite displays large discharge capacity of 1273 mAh g−1 at 0.1 A g−1, superior rate ability (594 mAh g−1 even at 10 A g−1) as well as excellent cycling performance as anodes for Li-ion batteries. As for sodium-ion storage, the SnS x /N-rGO-30 nanocomposite exhibits high reversible capacity of 640 mAh g−1 at 0.1 A g−1 and high rate capability of 225 mAh g−1 at 10 A g−1. [ABSTRACT FROM AUTHOR]

• Cable-like PI@CNTs is designed and prepared via an in-situ polymerization approach. • The PI@CNTs anode exhibits far better long-term cycling performance than pure PI. • The structure of PI@CNTs facilitates Li ion diffusion and electron transportation. Polyimide (PI) with C = O groups and C 6 rings is considered as a promising anode material for lithium ion batteries. However, the potential application of PI is extremely hindered by its inherent properties with unsatisfied lithium ions diffusion and electron conductivity. Herein, the PI nanoflakes are grown on the carbon nanotubes (CNTs) to construct a cable-like structure (PI@CNTs) via an in-situ polymerization approach. The dispersed PI nanoflakes provide shorter lithium ion transmission distance and the CNTs substrate promotes electron transportation, leading to enhanced electrochemical performance. When served as anode material, PI@CNTs exhibits a specific capacity of 493 mAh g−1 at 1 A g−1 after 2000 cycles, demonstrating remarkable long-term cycling properties. Moreover, the kinetic analysis reveals that the increased capacity can be ascribed to an enlarged diffusion-controlled process. In addition, the COMSOL simulation displays the high concentration of Li ions flux on the PI@CNTs surface. This work suggests a facile strategy to fabricate capable hierarchical polymer electrode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

A bi-functional electrode material of self-supporting N-doped C foam grown Pd nanoparticles (Pd@N/C-8 foam) for NaBH 4 electrooxidation and H 2 O 2 reduction reaction is successfully prepared. The Pd@N/C-8 foam electrode is fabricated by sacrificial template synthesis of N/C foam followed by 8 repetitive Pd impregnation reduction cycles. The Pd@N/C-8 foam electrode exhibits an extraordinary catalytic performance (642 mA cm−2 at −0.2 V) in 2 mol L−1 NaOH and 0.3 mol L−1 NaBH 4 , which is due to the large electrochemical active surface area, low activation energy (E a = 10.34 kJ mol−1) and 60.83% utilization efficiency of NaBH 4. Besides, its catalytic density for H 2 O 2 electroreduction reaches 648 mA cm−2 at −0.2 V in 2 mol L−1 H 2 SO 4 +1.3 mol L−1 H 2 O 2. The kinetic parameters show that the electrooxidation of BH 4 − and the electroreduction of H 2 O 2 on Pd@N/C-8 foam electrode are first-order reactions, and the number of transferred electrons are 5.8 and 1.56, respectively. Further exploration of Pd@N/C-8 foam electrode on the direct sodium borohydride-hydrogen peroxide fuel cell (DBHPFC) displays the maximum power density of 137 mW cm−2 and a superior stability. In view of the excellent performance, Pd@N/C foam will be a highly efficient electrode material of DBHPFC. • A novel Pd decorated 3D porous N/C foam has been successfully prepared. • Pd@N/C-8 foam can be applied to both anode and cathode of DBHPFC. • Pd@N/C-8 foam can effectively improve the fuel utilization. • DBHPFC presents excellent operation stability. [ABSTRACT FROM AUTHOR]

Designing earth-abundant hydrogen evolution reaction (HER) electrocatalysts with superior performance and eminent stability is the key to the practical production of high purity hydrogen. In the present work, Mn oxides with various valence state complex Fe–Ni sulfide (Mn x O y @FNS) heterogeneous materials were successfully fabricated through a feasible two-step hydrothermal process and can be directly used as active and efficient HER electrodes in alkaline media. This binder-free and defect-rich catalyst barely requires 105 and 365 mV to achieve −10 and −500 mA cm−2, respectively. Profiting from the disordered structure and the efficient interfacial effects between Mn oxides and Fe–Ni sulfide (FNS), this heterogeneous catalyst reveals sufficient electroactive sites, ample active edges and optimal electroconductivity. Additionally, during the 20 h HER reaction, the Mn x O y @FNS electrode exhibits outstanding durability. • Interlaced and plicated nanostructure provides sufficient exposed edge. • The disordered structure in Mn x O y @FNS afford plentiful electroactive sites. • This binder-free and defect-rich Mn x O y @FNS needs 105 to attain −10 mA cm−2. • This electrocatalyst exhibits excellent HER stability. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) reduced graphene networks (RGN) were successfully fabricated on Ni foam without any conductive agents and polymer binders by dipping commercial Ni foam into graphene oxide (GO) suspension and subsequent a electroreduction process in a buffer solution. Au nanoparticles were then deposited on the RGN through an electrodeposition process to form a novel reduced graphene networks-Au (RGNA) electrode. The morphology and phase structure of the RGNA electrode are characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction spectrometer. The NaBH 4 electrooxidation performance on the RGNA electrode is investigated by means of cyclic voltammetry and chronoamperometry. The RGNA electrode owns special hierarchical porous structure, rapid electron and ion transport, and large electroactive surface area due to the intrinsic electronic conductivity, mesoporous nature of graphene. The RGNA electrode exhibits a good stability during the electrochemical process and the oxidation current density at RGNA electrode reached 500 mA cm −2 at 0 V in the solution containing 0.1 mol dm −3 NaBH 4 and 2 mol dm −3 NaOH, which is higher than that at bare Au–Ni foam without graphene. The excellent structural stability and high catalytic performance for NaBH 4 electrooxidation make the RGNA a promising material for future energy systems. [ABSTRACT FROM AUTHOR]

Nickel-cobalt nanowire arrays (Ni-Co NWAs) electrode is prepared by one-step galvanostatic electrodeposition with a polycarbonate membrane as the template. By adjusting the Co proportion in the Ni and Co bath solution into 10%, the optimal Ni-Co NWAs electrode in terms of relatively lower onset potential and highest current density towards urea electro-oxidation is obtained. Its catalytic performance is investigated by constructing single direct urea/hydrogen peroxide (H 2 O 2 ) fuel cell. Results show that a peak power density of 7.4 mW cm −2 and an open circuit voltage of 0.92 V are achieved at room temperature when 9.0 mol L −1 KOH and 0.33 mol L −1 urea are used as the anolyte, H 2 SO 4 and H 2 O 2 as the catholyte. Additionally, the urea/H 2 O 2 fuel cell also demonstrates excellent stability during short term duration test. [ABSTRACT FROM AUTHOR]

Development of MnO 2 based electrode materials for supercapacitor application with high comprehensive electrochemical performance, such as high capacitance, superior reversibility, excellent stability, and good rate capability, is still a tremendous challenge. In this work, a distinctive interwoven three-dimensional (3D) structure electrode with ultra-thin 2D graphene nanosheet decorated on the surface of 1D C/TiC nanowire array is built as the support to immobilize MnO 2 nanoflakes (MnO 2 -Graphene nanosheet-C/TiC nanowire array, denoted as MGCT). Compared with the normal 1D core/shell structure, this novel 3D architecture can dramatically not only increase the surface area for MnO 2 loading but also facilitate the ion and electron transfer. The electrochemical performance of the as-prepared 3D MnO 2 electrode is evaluated by cyclic voltammetrys, galvanostatic charging-discharging tests and electrochemical impedance spectroscopy, high specific capacitance (856 F g −1 at 2 A g −1 ), good rate capability (69.1% capacitance retention at 40 A g −1 vs 2 A g −1 ), superior reversibility, and cycling stability (85.7% capacitance retention after 10,000 cycles at 10 A g −1 ) are obtained, suggesting that this novel structure can offer a new and appropriate idea for obtaining high-performance supercapacitor electrode materials. [ABSTRACT FROM AUTHOR]

Two trifunctional phenylethynyl-terminated imide oligomers, m-TPEPA and p-TPEPA, were systematically compared with the corresponding bifunctional phenylethynyl-terminated imide oligomer, BPEPA. The non-isothermal curing kinetics, Master Plots method, and rheological behaviour of the three high performance oligomers were systematically studied by dynamic DSC, small amplitude oscillatory shear rheometry, and infrared spectroscopy. The results show that the activation energy (Ea) depended on the extent of conversion evaluated with three different methods, and the lower Ea values of the trifunctional oligomers, which may lead to different curing reactions, compared with the sustained growth of Ea values of BPEPA. The chemorheological properties of the oligomers were measured and fit numerically with the dual Arrhenius model and gel model. Moreover, the degree of cure (agel) at the gel time (tgel) was calculated by the value of glass transform temperature at different curing temperature combined with rheological and isothermal DSC results. According to structural changes during the curing reaction characterised using FTIR spectra, it was inferred that the structures of the cured trifunctional imide resins have cis-configurations, which may change the part of the configuration from cis to trimerisation with the lower activation energies found in the later part of the conversion, while the difunctional imide structure is trans. [ABSTRACT FROM AUTHOR]

Urea peroxide as a solid-state fuel instead of liquid hydrogen peroxide is electro-catalytic oxidized by nickel nanowire arrays (NWAs) electrode. Nickel NWAs electrode is prepared by galvanostatically electrodepositing nickel into the pores and over-plating on the surface of polycarbonate template (PCT) from nickel bath solution. The NWAs are obtained after dissolving PCT in methylene chloride. Results show that urea peroxide decomposes into hydrogen peroxide and urea in aqueous solutions, then is electro-oxidized via two processes: i, hydrogen peroxide electro-oxidation at lower potential region; ii, both hydrogen peroxide and urea electro-oxidation at higher potential region. The onset oxidation potential and current density of urea peroxide electro-oxidation in 6.0 mol L −1 KOH and 1.0 mol L −1 urea peroxide are ca. -0.2 V and 700 mA cm −2 at 0.6 V, respectively. The nickel NWAs electrode demonstrates excellent stability for urea peroxide electro-oxidation under different polarization potentials. [ABSTRACT FROM AUTHOR]

Nanoporous palladium supported on the carbon coated titanium carbide (C@TiC) nanowire arrays (Pd NP/C@TiC) are successfully prepared by a facile chemical vapor deposition of three-dimensional (3D) C@TiC substrate, followed by electrochemical codeposition of Pd–Ni and removal of Ni via dealloying. The structure and morphology of the obtained Pd NP/C@TiC electrodes are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) are used to examine the catalytic performances of the electrodes for H 2 O 2 electroreduction in H 2 SO 4 solution. The Pd NP/C@TiC electrode exhibits a largely effective specific surface area owing to its open nanoporous structure allowing the full utilization of Pd surface active sites. At the potential of 0.2 V in 2.0 mol L −1 H 2 O 2 and 2 mol L −1 H 2 SO 4 solutions, the reduction current density reaches 3.47 A mg −1 , which is significantly higher than the catalytic activity of H 2 O 2 electroreduction achieved previously with precious metals as catalysts. [ABSTRACT FROM AUTHOR]

A novel three-dimensional carbon- and binder-free nickel nanowire arrays (Ni NAs) electrode is successfully fabricated by a facile galvanostatic electrodeposition method using polycarbonate membrane as the template. The Ni NAs electrode achieves a oxidation current density (divided by the electroactive surface areas of Ni) of 25.1 mA cm −2 in 4 mol L −1 KOH and 0.9 mol L −1 H 2 O 2 at 0.2 V (vs. Ag/AgCl) accompanied with a desirable stability, which is significantly higher than the catalytic activity of H 2 O 2 electro-oxidation achieved previously with precious metals as catalysts. The impressive electrocatalytic performance is largely attributed to the superior 3D open structure and high electronic conductivity, which ensures the high utilization of Ni surfaces and makes the electrode have higher electrochemical activity. The apparent activation energy of H 2 O 2 electro-oxidation on the Ni NAs catalyst is 13.59 kJ mol −1 . A direct peroxide–peroxide fuel cell using the Ni NAs as anode exhibits a peak power density of 48.7 mW cm −2 at 20 °C. The electrode displays a great promise as the anode of direct peroxide–peroxide fuel cell due to its low cost, high activity and stability. [ABSTRACT FROM AUTHOR]

Silver particles with microspheric structure are directly electrodeposited on carbon fiber cloth (CFC) substrate by square-wave potential electrodeposition method. The electrocatalytic behaviors of the Ag/CFC electrode toward hydrazine oxidation in alkaline solution are examined by cyclic voltammetry and chronoamperometry. An onset oxidation potential of -0.5 V and a peak current density of 30 mA cm −2 are achieved in the solution containing 1.0 mol L −1 KOH and 20.0 mmol L −1 hydrazine. The microspheric structure of the Ag/CFC electrode provides large electroactive surface area, hence, abundant active sites are vacant for hydrazine oxidation. The calculated apparent activation energies at different potentials show that hydrazine electro-oxidation at higher potential has faster kinetics than that at lower potential. In addition, the transfer electron number of hydrazine oxidation reaction on the Ag/CFC electrode is close to four, suggesting hydrazine is almost completely electrooxidized on the electrode and the full use of hydrazine fuel is basically achieved. [ABSTRACT FROM AUTHOR]

In this article, a three-dimensional electrode (Pd-CNT/Ni foam) based on Pd nanoparticles and carbon nanotubes (CNTs) is successfully developed by a simple “dipping and drying” process and a potentiostatic deposition technology for H 2 O 2 reduction in base medium. The composition and structure of Pd-CNT/Ni foam electrode are examined by X-ray diffractometer, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, respectively. The cyclic voltammetry (CV) and chronoamperometry (CA) techniques are applied to determine the electrochemical performance. The electrode exhibits a high catalytic activity for H 2 O 2 electroreduction, and it outperforms Pd/Ni foam electrode without CNT coating. At the reduction potential of −0.8 V, the reduction currents on Pd-CNT/Ni foam electrode can reach 323 mA cm −2 , however, it is only 192 mA cm −2 on Pd/Ni foam electrode, which is increased by 68.2%. The impressive electrocatalytic performance is largely attributed to the superior open structure and high electronic conductivity, which allows the high utilization of Pd surfaces and makes the electrode have higher electrochemical activity. These findings may provide the opportunity on preparing binder-free carbon-supported electrode in the application of fuel cells. [ABSTRACT FROM AUTHOR]

Herein, Polypyrrole was used as the conductive wrapping material electro-deposited on the MnO 2 nanoflakes covered on C/TiO 2 nanowire arrays to form PPy@MnO 2 @C/TiO 2 double shell/core structured arrays electrode for supercapacitor. Their structure and surface morphology were studied by using X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. The results suggest that a thin layer of PPy was successfully wrapped on the surface of MnO 2 , and the shell/core structure of MnO 2 @C/TiO 2 nanowire arrays was not changed after electro-deposition of PPy. The electrochemical tests indicate that the PPy@MnO 2 @C/TiO 2 double shell/core arrays electrode exhibits high specific capacitance of 715 F g −1 at a charge/discharge current density of 1 A g −1 and improved specific capacitance retention to 84.0% after 1000 cycles. These results show that the unique three dimensional (3D) double shell/core structured electrode holds promise for high-performance energy storage devices. The superior capacitive perfomance may due to the unique 3D C/TiO 2 nanowires and the unique double shell/core structures. Firstly, the 3D C/TiO 2 nanowire arrays, as excellent platform for loading active materials, can facilitate the permeation of electrolyte. Moreover, the thin layer PPy tightly wrapped on the MnO 2 nanoflakes can improve the electrical conductivity of MnO 2 . Therefore, the PPy@MnO 2 @C/TiO 2 electrode is promising candidate for electrochemical energy applications. [ABSTRACT FROM AUTHOR]

M 1/3 Ni 1/3 Mn 2/3 O 2 (M = Mg or Zn) is sucessfully synthesize from Na 2/3 Ni 1/3 Mn 2/3 O 2 via a electrochemical conversion method. The structure and morphology of the as-prepared material are systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS), respectively. The nano-sized morphology of M 1/3 Ni 1/3 Mn 2/3 O 2 is beneficial for the reduction of diffusion length and transfer acceleration of cations from the surface into the bulk interiors. XRD patterns reveal that crystal structure is maintained after the reversible Mg 2+ or Zn 2+ intercalation/deintercalation. Its performance for Mg 2+ and Zn 2+ intercalation/deintercalation in aquesous electrolytes is evaluated by cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. Mg 1/3 Ni 1/3 Mn 2/3 O 2 exhibits an initial capacity of 170.5 mAh g −1 in 1 mol L −1 Mg(NO 3 ) 2 , Zn 1/3 Ni 1/3 Mn 2/3 O 2 displays capacity of 113.7 mAh g −1 in 1 mol L −1 ZnSO 4 . Mg 1/3 Ni 1/3 Mn 2/3 O 2 shows a good cycling performance and maintains 52.7 mAh g −1 at 1.0C after 200 cycles in 1.0 mol L −1 MgSO 4 . [ABSTRACT FROM AUTHOR]

Ni foam supporting flower-like Co nano-particles (Co NFs/Ni foam) are successfully synthesized by a simple electrochemical method. The electrodes are characterized by scanning electron microscopy equipped with an energy dispersive X-ray spectrometer, and X-ray diffractometer. Without any conducting carbons and polymer binders, the 3D electrode with a unique structure is directly used as the noble metal-free catalyst for hydrazine oxidation and the catalytic performance is evaluated by voltammetry and chronoamperometry. The Co NFs/Ni foam electrode exhibits excellent catalytic performance and superior stability for hydrazine electrooxidation in alkaline media. In the solution of 1.0 mol L − 1 NaOH + 30 mmol L − 1 N 2 H 4 , the oxidation current density at − 0.8 V is 140 mA cm − 2 for the Co NFs/Ni foam electrode, and it is only 42 mA cm − 2 for the Pt/Ni foam electrode. Also, the onset potential for Co NFs/Ni foam electrode can reach to − 1.06 V (only − 0.72 V for Ni foam), suggesting that the high cell voltage of DHFC with Co NFs/Ni foam anode. These merits are benefitting from the unique 3D structure which can ensure high utilization of catalysts. [ABSTRACT FROM AUTHOR]

In this paper, freestanding one-dimensional MnO 2 nanoflakes are successful prepared through a simple hydrothermal reaction by using the carbon shell of TiC/C core/shell arrays as the sacrificial template. Its structure and morphology are characterized by X-ray diffractometer, X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrometer and transmission electron microscopy. Results show that the thickness of the carbon shell decreased but also remained and the ultrathin MnO 2 nanoflakes with thickness less than 5 nm uniformly grow on the surfaces of the TiC/C nanowire to form a core/double shell structure after the hydrothermal reaction. The electrochemical performance of the as-prepared electrode is evaluated by cyclic voltammetrys, galvanostatic charging-discharging tests and electrochemical impedance spectroscopy, and high capacities, excellent rate capabilities and exemplary cycling performance is obtained. The as-prepared electrode shows a high specific capacitance of 598.8 F g −1 and 85.8% of its initial capacitance is retained after 10,000 cycles at a high discharge current density of 10 A g −1 , suggesting that this structure has a promising future as high-performance supercapacitor electrode. [ABSTRACT FROM AUTHOR]

Flexible and binder-free multi-walled carbon nanotube (MWNT)-modified sponge-based nickel (Ni) is employed as the electrode material for methanol (CHOH) electrooxidation. The nano-spherical Ni is electrodeposited on the surface of the MWNTs which are assembled on the skeleton of a commercial sponge. The as-prepared MWNT-modified sponge-based Ni electrode (MSNi) is characterized by scanning electron microscopy, transmission electron microscope, and X-ray diffractometer. The catalytic activity of the MSNi electrode for CHOH electrooxidation is investigated by means of cyclic voltammetry, chronoamperometry, and electrochemical impedance spectra. The preparation process of the flexible MSNi electrode does not use any binder and it exhibits a unique three-dimensional (3D) network-porous structure. The MSNi exhibits a high electrocatalytic performance of 23 mA (cm mg) in 0.5 mol dm CHOH at 0.5 V. [ABSTRACT FROM AUTHOR]

Pt-modified Co nanosheet@carbon sponge (Pt-Co NS@carbon sponge) electrode is synthesized via a facile sponge carbonization method coupled with a direct Co electrodeposition and Pt chemical-deposition. The obtained electrodes are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The catalytic performances of H 2 O 2 electroreduction in alkaline medium are investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The Pt-Co NS@carbon sponge electrode exhibits unique nanosheet structure on the three-dimensional (3D) porous network skeleton with a large surface area and displays excellent catalytic performance. The Pt-Co NS@carbon sponge electrode achieves a reduction current density of −1.38 A cm −2 mg −1 in 3.0 mol L −1 KOH and 1.5 mol L −1 H 2 O 2 at −0.50 V (vs. Ag/AgCl) accompanied with a desirable stability, which is significantly higher than the catalytic activity of H 2 O 2 electroreduction achieved previously with precious metals as catalysts. The impressive electrocatalytic performance is largely attributed to the superior 3D open structure and high electronic conductivity, which ensures the full utilization of Pt surfaces and makes the electrode have higher electrochemical activity. Original Pt-Co NS@carbon sponge electordes have a great potential for the application in fuel cells due to its facile preparation, high performance and low cost. [ABSTRACT FROM AUTHOR]

The size-controlled hierarchical textile-like Au nanostructures supported carbon fiber cloth (Au NTs/CFC) is successfully fabricated through a simple low-cost electrochemical route. The electrodes are characterised by scanning electron microscopy equipped with an energy dispersive X-ray spectrometer, transmission electron microscopy and X-ray diffractometer. Without any conducting carbons and polymer binders, the 3D electrode with unique structure is directly used as the electrocatalyst for H 2 O 2 reduction in acid solution and the catalytic performance is evaluated by voltammetry and chronoamperometry. The Au NTs/CFC electrode exhibits much higher catalytic activity and remarkably improved utilization of Au than Au nanoparticles (Au NPs/CFC) prepared by the same method owing to its unique structure. In the solution of 3.0 mol L −1 H 2 SO 4 + 0.1 mol L −1 H 2 O 2 , with the reduction potential of 0 V, the current of −0.72 A cm −2 mg −1 can be obtained on Au NTs/CFC electrode and only a current of −0.09 A cm −2 mg −1 can be achieved on Au NPs/CFC electrode. All these results reveal that the novel Au NTs/CFC electrode exhibits excellent catalytic performance and superior stability for H 2 O 2 electroreduction in acid medium, benefitting from the unique 3D structure which can ensure high utilization of catalyst. [ABSTRACT FROM AUTHOR]

Three dimensional (3D) honeycomb-like NiS 2 /NiO nano-multiple materials were successfully prepared by fabricating cribrate NiS 2 on the surface of NiO nanosheets through simple hydrothermal process on nickel foam. The morphology and phase structure of the NiS 2 /NiO are characterized by scanning electron microscopy equipped with energy dispersive X-ray spectrometer, transmission electron microscope, X-ray diffractometer and the electrochemical properties are tested by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The NiS 2 /NiO electrode owns lower electrochemical impedance compared with bare NiO substrate and exhibits exceptional capacitance performance with a high specific capacitance of 2251 F g −1 delivered at current density of 1 A g −1 , while 1192 F g −1 retained at 20 A g −1 . What's more, after 2000 cycles, the specific capacitance remains 1275 F g −1 (at 5 A g −1 ) with a capacitance retention of 78%. Therefore, the NiS 2 /NiO electrode shows remarkable electrochemical performance and has a promising future for electrochemical supercapacitors. [ABSTRACT FROM AUTHOR]

Highly porous nickel@carbon sponge electrode with low cost is synthesized via a facile sponge carbonization method coupled with a direct electrodeposition of Ni. The obtained electrodes are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The catalytic performances of urea electro-oxidation in alkaline medium are investigated by cyclic voltammetry (CV) and chronoamperometry (CA). The Ni@carbon sponge electrode exhibits three-dimensional open network structures with a large surface area. Remarkably, the Ni@carbon sponge electrode shows much higher electrocatalytic activity and lower onset oxidation potential towards urea electro-oxidation compared to a Ni/Ti flat electrode synthesized by the same procedure. The Ni@carbon sponge electrode achieves an onset oxidation potential of 0.24 V (vs. Ag/AgCl) and a peak current density of 290 mA cm −2 in 5 mol L −1 NaOH and 0.10 mol L −1 urea solutions accompanied with a desirable stability. The impressive electrocatalytic activity is largely attributed to the high intrinsic electronic conductivity, superior porous network structures and rich surface Ni active species, which can largely boost the interfacial electroactive sites and charge transfer rates for urea electro-oxidation in alkaline medium, indicating promising applications in fuel cells. [ABSTRACT FROM AUTHOR]

In this work, Au nanoparticles directly grown on the surface of TiO 2 core-C shell (Au/C@TiO 2 ) has prepared by a simple electrodeposition method for the first time. The morphology is characterized by scanning electron microscope, and its structure is investigated by X-ray diffraction. Au nanoparticles are uniformly distributed on the surface of C@TiO 2 nanowire array. Its catalytic performance for NaBH 4 oxidation is evaluated by cyclic voltammetry and chronoamperometry measurement. The results indicate that Au/C@TiO 2 shows a good and stable catalytic performance. In 2 mol cm −3 NaOH and 0.2 mol cm −3 NaBH 4 the oxidation current density for the electrooxidation of BH 4 − can reach 475 mA cm −2 at 0 V. The electrons transfer number released by BH 4 − electrooxidation on Au/C@TiO 2 electrode has been found to be a 6-electron process. The high performance is mainly attributed to its 3D structure which can promote the mass transport of NaBH 4 , electronic conductivity and Au utilization. [ABSTRACT FROM AUTHOR]

The unique Au nanosheets (Au NSs) are electrodeposited uniformly on Ni foam substrate via a one-step potentiostatic electrodeposition technique. The electrode is characterized by scanning electron microscopy equipped with energy dispersive X-ray spectrometer and X-ray diffractometer. It shows a unique open structure allowing the full utilization of Au surface active sites. NaBH 4 electrooxidation in KOH solution on the Au NSs/Ni foam electrode are studied by linear sweep voltammetry and chronoamperometry. The electrode exhibits a high catalytic performance outperforming the Au particles made by the same method. At the oxidation potential of 0 V, the current density of 827 mA cm −2 can be achieved on Au NSs/Ni foam electrode, and only 219 mA cm −2 was obtained on Au NPs/Ni foam electrode, indicating that the catalytic activity is increased by 278%, which is attributed to the porous 3D structure, ensuring the full utilization of Au surfaces. Besides, H 2 generated by NaBH 4 hydrolysis can quickly diffuse away from the electrode, preventing surface active sites of Au from blocking by adsorbed gas bubbles. [ABSTRACT FROM AUTHOR]

Fully metallic nickel nanowire arrays (NWAs) electrode is prepared by electrodepositing nickel within the pores and over-plating on the surface of polycarbonate template (PCT) with subsequent dissolution of the template in dichloromethane. The as-prepared electrode is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Urea electro-oxidation reaction in KOH solution on the nickel NWAs electrode is investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) tests. The results show that the nickel NWAs electrode achieves an onset oxidation potential of 0.25 V (vs. Ag/AgCl) and a peak current density of 160 mA cm −2 in 5 mol L −1 KOH and 0.33 mol L −1 urea accompanied with considerable stability. [ABSTRACT FROM AUTHOR]

In this work, Co(OH) 2 buds direct growth on Ni foam (Co(OH) 2 buds/Ni foam) is prepared via a hydrothermal method. Their structure and morphologies are characterized by using X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. Result shows that the Co(OH) 2 buds are assembled by several nanorods and uniformly covered on the surface of Ni foam. Due to its unique structure, the Co(OH) 2 buds/Ni foam electrode shows high capacitive performance and long cycle life. The specific capacitance of Co(OH) 2 buds/Ni foam is as high as 2041 F g −1 at a current density of 3 mA cm −2 in 6 M KOH electrolyte, and 811 F g −1 even at a high current density of 60 mA cm −2 . The capacitance of the Co(OH) 2 buds/Ni foam electrode remained 72.4% after 1000 cycles at 18 mA cm −2 . An asymmetric supercapacitor was successfully assembled, in which Co(OH) 2 buds/Ni foam and AC used as positive and negative electrode, respectively. The energy density of the AC//Co(OH) 2 buds/Ni foam supercapacitor reaches to 20.3 W h kg −1 at a power density of 90.6 W kg −1 . Our result shows that the Co(OH) 2 materials are promising candidate for electrochemical energy applications. [ABSTRACT FROM AUTHOR]

Direct carbon fuel cells are promising power sources with their performance significantly depending on the electrooxidation activity of carbon fuel. The impurities in the carbon fuel may affect the anode reactions. Sulfur and some of its inorganic compounds (CaSO 4 , K 2 SO 3 , K 2 S, FeS 2 ) were added in molten carbonate and their effect on graphite electrooxidation was investigated. Cyclic voltammograms of gold electrode with addition of these sulfur compounds showed CaSO 4 was stable and other compounds were electrochemically oxidized to high valence state sulfur compounds at operating voltage range. Linear sweep voltammetry of graphite with addition of sulfur compounds exhibited enhanced current density compared to pure graphite electrooxidation. Chronoamperometry was carried out to examine steady-state test of graphite electrooxidation in presence of sulfur compounds and the results indicated the enhanced current densities were caused by improved Boudouard reaction for CaSO 4 and sulfur electrooxidation for other compounds, respectively. These inorganic sulfur compounds had no impact on electrooxidation process of graphite. [ABSTRACT FROM AUTHOR]

In this report, graphene nanosheets (GNS)/nickel sulfide (NiS) based material for high-performance supercapacitor is prepared by “dip and dry” and electrodeposition methods. Commercial flexible make-up cottons (MCs) are chose as skeletons to construct homogeneous three-dimensional (3D) interconnected graphene-wrapped macro-networks, which can support structures for high loading of active electrode materials and facilitate the access of electrolytes to active electrode materials. The hybrid GNS/NiS based MCs (denoted as MCs@GNS@NiS) electrode yields relatively high specific capacitance of 775 F g −1 at a charge/discharge specific current of 0.5 A g −1 and good capacitance retention of 88.1% after 1000 cycles at 2 A g −1 . Furthermore, the MCs@GNS@NiS electrode delivers a high energy density of 11.2 Wh kg −1 at even a high power density of 1008 W kg −1 . Therefore, such low-cost and high-performance energy MCs based on GNS/NiS hierarchical nanostructures offer great promise in large-scale energy storage device applications. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) multilayer porous MnO 2 /reduced graphene oxide composites are coated on a nickel foam substrate (denoted as MnO 2 /R-GO@Ni-foam) by a facile and scalable spray method following by low temperature annealing. The composite electrodes are characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The content of MnO 2 in the MnO 2 /R-GO@Ni-foam composites is determined by thermal gravimetric analysis. The supercapacitive performance of the composite electroides is investigated by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The results show that the MnO 2 /R-GO@Ni-foam composite displays a high specific capacitance of 267 F g −1 at 0.25 A g −1 and excellent capacitance retention of 89.5% after 1000 cycles. This study provides a facile way for the preparation of composite electrodes for high-performance supercapacitor. [ABSTRACT FROM AUTHOR]

A high-performance capacitor battery AC/ λ -MnO 2 based on Na-ion insertion-deinsertion into λ -MnO 2 in 1 mol dm −3 Na 2 SO 4 solution is successfully demonstrated. A simple acid leaching technique is used to produce λ -MnO 2 by treating LiMn 2 O 4 with H 2 SO 4 . X-ray power diffraction and inductively coupled plasma analysis provide supporting evidences for the extraction of Li + from the LiMn 2 O 4 , and the particle morphology of λ -MnO 2 is studied by scanning and transmission electron microscopy. A high specific capacity of 390.7 mAh g −1 is obtained for the λ -MnO 2 electrode at a current density of 13.6 mA g −1 with a nearly 100% efficiency. The capacitor battery AC/ λ -MnO 2 can operate at a cell voltage as high as 2.2 V, and it exhibits a specific energy of 19.7 Wh Kg −1 at a high power density of 3500 W Kg −1 and a high energy density of 71.7 Wh Kg −1 at a low power density of 403 W Kg −1 . It has potentials to be used as an energy storage device for the integration of solar and wind power into the electrical power grid. [ABSTRACT FROM AUTHOR]

A low-cost and binder-free cobalt electrode is prepared by the electrodeposition of Co nanoplates onto a flexible conductive substrate, which is prepared simply by scratching a piece of A4 paper with a common 8B pencil. The morphology and phase structure of the cobalt–graphite–paper (CGP) electrode are characterized by scanning electron microscopy, transmission electron microscopy and an X-ray diffractometer. The catalytic activity of the CGP electrode for NaBH4 electro-oxidation is investigated by cyclic voltammetry and chronoamperometry. The catalyst combines tightly with the paper and exhibits a good stability. The oxidation current density reaches up to 180 mA cm−2 in 1 mol dm−3 NaOH and 0.10 mol dm−3 NaBH4 at −0.4 V. [ABSTRACT FROM AUTHOR]

Ni foam supported-NiCo 2 O 4 nanostructures with various morphologies are successfully prepared by a facile template-free method. The synthesis involves the electrodeposition of the bimetallic (Ni, Co) film on Ni foam support. The NiCo 2 O 4 nanostructures are formed by immersing the bimetallic film in an oxalic acid solution, followed by a calcination progress. The control over NiCo 2 O 4 nanostructures with different morphologies is achieved by adjusting the electrodeposition time and immersing time. The electrode is characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. H 2 O 2 electrooxidation and electroreduction in KOH solution on the NiCo 2 O 4 nanostructures are studied by cyclic voltammetry and chronoamperometry. Results show that NiCo 2 O 4 nanostructures exhibit high performance and superior stability for both H 2 O 2 electrooxidation and electroreduction, resulting from hierarchical porous structure inside their architectures. [ABSTRACT FROM AUTHOR]

Abstract: A facile and green method is developed to fabricate Fe3O4–Fe nanowires with a large amount of nanoholes directly grown on highly conductive nanofiber arrays. By electrodeposition of Fe clusters on C/TiC nanofiber array, followed by in-situ chemical conversion of Fe to FeC2O4–Fe nanowires and the thermal decomposition of FeC2O4–Fe to Fe3O4–Fe, a Fe3O4–Fe nanocomposite electrode with unique architecture is successfully prepared. The electrode is characterized by means of X-ray diffractometer, scanning electron microscope and transmission electron microscope. Electrochemical properties of the nanowire arrays electrode as the anode of lithium-ion batteries are examined by cyclic voltammetry and galvanostatic charge/discharge test. The electrode displayed remarkably high capacity, excellent high rate performance and superior cycling stability. The reversible capacity of the electrode reached 1012 mAh g−1 at 1C and retained to be 500 and 255 mAh g−1 at 10 and 20C, respectively. It can still deliver a specific capacity of 100 mAh g−1 even at 50C (72 s charge–discharge). The electrode also has a satisfactory cycling performance with capacity retention of 93.9% after 100 cycles at 1C. The magnificent performance can be attributed to the distinct configuration resulting from the novel fabrication process. [Copyright &y& Elsevier]

Abstract: Non-noble metal film electrode (Co/Ni foam) modified with noble metals (Au and Pd) has been reported. Highly porous Co film is firstly prepared electrochemically on the commercial Ni foam substrate and in turn serves as a hard template and a redox inducer for modification by spontaneous deposition of Au or Pd. The electrodes (Au-modified Co/Ni foam and Pd-modified Co/Ni foam) are characterized by scanning electron microscopy equipped with energy dispersive X-ray spectrometer, and X-ray diffractometer. The catalytic performance of the 3D porous electrodes is evaluated by voltammetry and chronoamperometry. Results reveal that Au- and Pd-modified Co/Ni foam exhibit excellent catalytic performance and good stability for H2O2 electroreduction compared with Au and Pd particles supported on Ni foam, benefitting from the unique 3D structure which can ensure high utilization of catalyst and quick releases of gas bubbles produced by H2O2 decomposition from the electrode. [Copyright &y& Elsevier]

Abstract: Flexible and wearable cobalt electrode with a unique three-dimensional hierarchical-network structure is prepared by electrodeposition of spherical Co particles onto multiwalled carbon nanotubes (MWNTs) which are assembled on the skeleton of cosmetic cotton (CC). The morphology and phase structure of the cobalt–multiwalled carbon nanotubes–cosmetic cotton (Co–MWNTs–CC) electrode are characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction spectrometer. The NaBH4 electrooxidation performance on the Co–MWNTs–CC electrode is investigated by means of cyclic voltammetry and chronoamperometry. Results show that the Co–MWNTs–CC electrode exhibits remarkably high catalytic activity and good stability for NaBH4 electrooxidation. The oxidation current density reaches as high as 170 mA cm−2 at −0.7 V in 1.0 mol dm−3 NaOH and 0.1 mol dm−3 NaBH4, which is higher than the most-related previous results. [Copyright &y& Elsevier]

Highlights: [•] MnO2/C/TiO2 shell/shell/core arrays electrode has been prepared by simple thermal reaction and electrodeposition method. [•] The unique shell/shell/core structure has easy access of electrolyte ions, large surface to volume and high electrochemical activity. [•] The MnO2/C/TiO2 shell/shell/core arrays exhibits high specific capacitance of 639 F g−1 at a charge/discharge current density of 1 A g−1. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fe2O3 sheets have been synthesized on nickel foam by a simple template-free growth process and heat treatment. [•] The Fe2O3 electrode exhibits a specific capacitance of 147Fg−1 at 0.36Ag−1 and 98Fg−1 at 3.6Ag−1. [•] The as-prepared Fe2O3 electrode presents a wider potential window of 1.0V. [Copyright &y& Elsevier]

Highlights: [•] λ-MnO2 is prepared by treating LiMn2O4 with H2SO4. [•] λ-MnO2 has ideal battery behavior for polyvalent cations (Mg2+, Zn2+) to intercalate/deintercalate in aqueous electrolyte. [•] λ-MnO2 electrode exhibits a high specific capacity of 545.6 mAh g−1 at 13.6mAg−1 in 0.5mol dm−3 MgCl2 electrolyte. [ABSTRACT FROM AUTHOR]

Abstract: Catalytic electrodes consisting of MmNi0.58Co0.07Mn0.04Al0.02 (AB5-type alloy) and multi-walled carbon nanotubes (MWNTs) are studied for NaBH4 electrooxidation and are characterized by scanning electron microscope and X-ray diffractometer. The NaBH4 electrooxidation performance on the AB5/MWNTs electrode is tested by cyclic voltammetry and chronoamperometry methods. The electrode performance is significantly affected by the content of MWNTs and the optimized content of MWNTs is found to be 2 wt.%. The steady state current density for NaBH4 electrooxidation at the AB5/MWNTs (2 wt.%) electrode is about twice of that at the AB5 electrode without MWNTs. The utilization efficiency of NaBH4 at the AB5/MWNTs electrode is 61.5% higher than that at the pristine AB5 electrode. The enhanced electrocatalytic activity and NaBH4 utilization at the AB5/MWNTs (2 wt.%) electrode can be attributed to MWNTs, which acts as a hydrogen adsorbent to diminish hydrogen release. [Copyright &y& Elsevier]

Carbon fiber cloth (CFC) supported Ni and Co electrodes are prepared by electrodeposition (Ni/CFC and Co/CFC). Their catalytic performance for H2O2 electrooxidation in KOH solution is investigated and compared with Au/CFC electrode. Ni/CFC electrode exhibits higher catalytic activity than Au/CFC and Co/CFC electrodes. The performance of a direct peroxide–peroxide fuel cell (DPPFC) with Ni/CFC anode and Pd/CFC cathode is examined. The cell shows a peak power density of 21.6 mW cm−2 at 20 °C and 53.8 mW cm−2 at 50 °C. The cell performance is improved with the increase of anolyte and catholyte flow rate and operation temperature. Results indicates that the performance of DPPFC with low-cost Ni/CFC anodes is comparable with those using precious metal anodes, e.g., Au/CFC and Pd/CFC. [ABSTRACT FROM AUTHOR]

Highlights: [•] Electrodeposition of Au nanothorns supported on Ni foam for NaBH4 oxidation is reported [•] The unique 3D electrode exhibits good catalytic performance for NaBH4 electrooxidation [•] The unique 3D electrode is consisted of thorn-like Au with the corrugated appearance. [Copyright &y& Elsevier]

Highlights: [•] Electrodeposition of Au nanoflowers supported on CFC for ethanol oxidation is reported. [•] Many thorn-like Au nanostructures have a common basis to form a single flower. [•] The as-prepared electrode exhibits good catalytic performance for ethanol electrooxidation. [Copyright &y& Elsevier]

Highlights: [•] MgFe2O4 nanoparticles are prepared by a sol–gel method. [•] The initial discharge specific capacity under the current density of 180mAg−1 reaches 1404mAhg−1. [•] The high specific capacities and good stability were due to its small particle size and the good electrochemical activity. [ABSTRACT FROM AUTHOR]

Abstract: Nanostructured Co x Ni1−x (OH)2 (x = 0, 0.053, 0.068, 0.116, 0.192) composites are synthesized via a simple template-free growth process onto nickel foam by using a mixed aqueous solution of nickel nitrate, cobalt nitrate and ammonia. Their structure and surface morphology are characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and scanning electron microscopy. The SEM images show changes in the microstructure of β-Ni(OH)2 by the doping of cobalt. The effects of cobalt content on the electrochemical behaviors of β-Ni(OH)2 are investigated by cyclic voltammetries, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show that the Co0.116Ni0.884(OH)2 composite electrode exhibits a drastic improvement in the capacitive characteristics of β-Ni(OH)2 with a specific capacitance increase from 386.4 to 1082.6 F g−1 at a high discharging current density of 6 A g−1. This work suggests that the as-prepared Co0.116Ni0.884(OH)2 composite electrode has a promising future as higher charging/discharging rate materials for pseudo-supercapacitors. [Copyright &y& Elsevier]