Three-dimensional (3D) electrodes hold great potential for supercapacitors (SCs) due to their unique architectures and prominent electrochemical properties. Herein, a kind of 3D FeOOH/reduced graphene oxide/Ni foam (FeOOH/rGO/NF) electrode with remarkable capacitive performance has been developed as a new anode for asymmetric supercapacitors (ASCs). Benefiting from the improved conductivity and increased surface area, the as-prepared 3D FeOOH/rGO/NF electrode exhibits a high areal capacitance of 406.5 mF cm−2 at 10 mV s−1. Moreover, when using the as-prepared 3D FeOOH/rGO/NF electrode as anode, a high-performance ASC device with a maximum volumetric energy density of 0.48 mWh cm−3 and excellent cycling stability is achieved.

⿢Magnetite nanotube array with three dimensional arrangement were synthesized via a facile templating route.⿢Further investigation found out that the nanotubes were assembled from numerous nanoparticles.⿢Small particle sizes responsible for high rate performance led to agglomeration and undermine cycling stability.A facile templating method was used to fabricate a Magnetite (Fe3O4) nanotubes coated carbon cloth electrode as anode for lithium ion batteries in this work. In hope of achieving high-performance and stable electrode, ZnO nanorods were first electrodeposited and subsequently used as sacrificial templates for synthesis of Fe3O4 nanotubes arrays. According to structural analysis, this strategy led to a uniform nanotubes-like coating attached on interwoven carbon fiber of the three-dimensional (3D) carbon cloth. Unexpectedly, it was found that the nanotube structure was assembled from numerous nanoparticles that formed up a hierarchical structure with 3D arrangement inherited from carbon cloth substrate. The as-prepared electrode delivered excellent rate capability, giving a maximal specific capacity of ⿼930 mAh g-1 at 2 A g-1 but a relatively poor cycling retention of 73% after 200 cycles. This is attributed to the severe agglomeration of nanocrystalline Fe3O4 particles upon repeated cycling, revealing the fact that small particles accounting for high rate performance might in turn undermine the cycling stability.

In this work, we fabricated a lightweight (1.25 g cm−3) N doped reduced graphene (N-RGO) paper through a combined method of vacuum filtration and thermal treatment under an ammonia atmosphere. 0.48% of N has been uniformly incorporated into the graphene sheets, which results in an inherent improvement in conductivity. Simultaneously, the as-fabricated N-RGO paper possesses excellent flexibility without any effect on its electronic properties. Furthermore, the good performance of N-RGO as a supercapacitor electrode was also demonstrated with a high specific capacitance of 280 F g−1 at 5 mV s−1. The N-RGO electrode also exhibited a remarkable long-term cycling stability with 99.4% capacitance retention after 40000 cycles. This work constitutes the first attempt of applying N-doping to improve the electronic properties and electrochemical performance for graphene paper.

CoFe2O4 porous nanosheets (CFOPNSs) on F-doped SnO2 coated glass (FTO) substrates with 30.5 nm average pore diameter were prepared through a template-free electrochemical method from aqueous solution. The CFOPNSs exhibit obvious absorption in the visible-near infrared light range, and obvious photocurrent responses under visible light illumination (λ ≥ 390 nm). Additionally, XPS and Raman results indicate that the valence band maximum (VBM) of the CFOPNSs occurs at the Co 3d level.

CoFe2O4 nanosheets (NSs) and nanoparticles (NPs) were successfully synthesized on F-doped SnO2 coated glass (FTO) substrate via a facile and controllable electrodeposition method. X-Ray photoelectron spectroscopy (XPS) results indicated that the CoFe2O4 NSs and NPs have different distributions of Co and Fe cations over tetrahedral and octahedral sites. The magnetic measurements showed that the prepared CoFe2O4 NSs exhibit higher value of magnetic properties, which can be mainly ascribed to the variation of the cation distribution.

Hierarchically branched MoO3 nanostructures on Ti substrates were successfully prepared via a simple and controllable electrodeposition–heat-treatment method. XPS and Raman results indicate that these branched MoO3 nanostructures possess some oxygen vacancies. The magnetic measurements show the prepared branched MoO3 nanostructures exhibit ferromagnetic behaviour at room temperature. The observed room-temperature ferromagnetism can be mainly ascribed to the oxygen vacancies on the surface of the samples.

Oxygen adsorption materials play an important role in catalysis. However, the conventional catalytic mechanism of CO oxidation over copper oxide-based catalysts is based on lattice-oxygen oxidation processes, which neglects the significance of the oxidizability of the copper component and the adsorbed oxygen. Herein, we propose that poorly-crystallized CuO nanorods are capable of adsorbing abundant oxygen along with increasing the Cu oxidation states to close to 3+, meaning that CO catalytic oxidation occurs directly on the adsorbed oxygen and that Cu oxidation states do not fall to 1+ during catalytic reactions. The rate-controlled step is the surface oxidizability of the CuO nanorods, which increases with increasing temperature and oxidizability of the environment involved. These catalytic processes are distinctly different from the conventional case. The unique oxygen adsorption and catalytic properties of the CuO nanorods originate from the increasing trend in Cu oxidation state in the p-type CuO, enhanced by the defect structures and coarse surfaces of the sample. Such structure and morphology characteristics are closely related to the liquid membrane growing environment, which induces poor crystallization of the nanorods. The characterization methods include scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transformation infrared spectroscopy (FTIR).

Nanostructured alloys have recently attracted great attention for hydrogen evolution due to their unique electron structure and large surface area. Herein, we reported a facile electrochemical method to prepare three-dimensional (3D) nano-network structures and demonstrated their feasibility as efficient electrocatalyst for hydrogen evolution. These 3D CoNiCu nano-network structure exhibited good performance in hydrogen evolution reaction (HER).Highlights► A facile method has been developed to synthesize 3D CoNiCu nano-networks. ► The diameter of nanowires can be controlled between 5 and 7 nm ► Their compositions could be controlled by adjusting the deposition parameters. ► These 3D CoNiCu nano-networks show good performance in HER. ► The i0/Rf ratio is excellence while compared to other non-noble alloys.

We report a facile, general and scalable approach towards porous La(OH)3/Pr(OH)3/Nd(OH)3 nanowires based on a gas bubble template electrochemical assembly process, and they exhibit a high adaptability for removing Congo red from water.

Herein, we present a template- and surfactant-free electrochemical method for the fabrication of hierarchical porous CeO2 NWs and NWAs. These porous NWs/NWAs have diameters of 50–200 nm and lengths of up to several micrometres. Both the NWs and NWAs exhibit an excellent ability to remove Congo red in wastewater treatment.

Large-scale La(OH)3 nanorod/nanotube arrays have grown directly on Cu substrates via a template-free electrodeposition and selective etching process.

Various morphologies of ZnO nanostructures can be obtained through a novel method, incorporating electrochemical corrosion with three modes: liquid membrane and above and below the water line in partial immersion. X-ray diffraction (XRD) patterns, high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) are employed to characterize their structure. The mechanism of the growth of NRs is proposed as electrochemical corrosion and oriented attachment, which occur in a liquid membrane or partial immersion in a vapor membrane. The evolution of ZnO nanostructures such as nanorods, nanowires, nanopins, and nanodentrites is observed, and the influence of concentration, reaction time, additives, state of substrate, membrane thickness, and solvent on the morphology of ZnO is investigated. Optical properties of ZnO nanostructures are studied by using UV−visible absorption spectra and photoluminescence (PL). Their optical gaps vary from different morphologies. Among the studied samples, short nanorods show the largest optical gap, while big nanorods present the smallest value of optical gap. PL properties demonstrate that peaks of near-band emission and defect-related luminescence are basically in the same position. However, intensities for different morphologies are of different values, and short nanorods exhibit the best near-band emissions.

The 3D nanostructured antimony is synthesized by simply immerging an anodically oxidized copper sheet into SbCl3-(n-Bu)4NBF4-DMSO solution at room temperature. The morphology, shape, and structure were characterized by FE-SEM, XRD, and HRTEM. The 3D nanostructured antimony has a regular fourteen-faced polyhedron shape and is constructed by Sb nanowires. The Sb nanowires are single crystals with a rhombohedral crystal structure, the average diameter of the Sb nanowires ranges from 5 to 8 nm. The HRTEM investigation and theoretical calculations indicate that Sb nanowires grow along the arrises of its rhombohedral lattice. The growth mechanism is proposed, the electron transport along Sb nanowires may be anisotropic and results in the preferred orientation of the Sb nanowires growth. The nanocages can be formed by quaric self-assembly of Sb nanowires because of the anisotropy of its rhombohedral crystal structure.

Fe–Mn alloy films have been prepared by electrodeposition in an organic bath containing FeCl2 + MnCl2 in dimethyl formamide. The electroreduction of Mn(II) was irreversible and the diffusion coefficient of Mn(II) was calculated to be 8.0 × 10− 11 m2 s− 1 at 298 K. An amorphous film of Fe–Mn was obtained by potentiostatic electrolysis. The Mn content varied from 4.8 at.% to 72.3 at.% with increase in the applied cathodic potential. Scanning electron microscope investigation showed that the deposited film was homogeneous and consisted of spherical particles. Nano-sized pores were observed in the surface of these particles. After heat treatment at 773 K, large crystal grains formed and X-ray diffraction patterns indicate that solid solution of Mn in γ-Fe occurred. The alloying temperature of the Fe–Mn film was determined to be 1013 K using differential thermal analysis.

Herein, we present a template- and surfactant-free electrochemical method for the fabrication of hierarchical porous CeO2 NWs and NWAs. These porous NWs/NWAs have diameters of 50–200 nm and lengths of up to several micrometres. Both the NWs and NWAs exhibit an excellent ability to remove Congo red in wastewater treatment.