•Hierarchical β-Ni(OH)2 microflowers encapsulated by rGO were fabricated.•The electrochemical properties were evaluated by specific capacity.•The β-Ni(OH)2/rGO electrode exhibits outstanding electrochemical properties.•The excellent supercapacitor performance is attributed to the synergistic effect.Flower-like β-Ni(OH)2 encapsulated by flexible reduced graphene oxide (rGO) nanosheets have been synthesized by one-pot hydrothermal process and were used as Faradaic electrodes for supercapacitors. β-Ni(OH)2 microflowers whose particle sizes ranging from 1.7 to 2.5 μm were effectively encapsulated by flexible rGO nanosheets. Due to the efficient charge transfer and unimpeded ion transports, such β-Ni(OH)2/rGO composites can deliver ultrahigh specific capacity of 618 C g−1 at a current density of 3 A g−1 and maintain 276 C g−1 at 30 A g−1 in 6 M KOH electrolyte. Besides, the β-Ni(OH)2/rGO composite electrode exhibits outstanding cyclic stability. When tested at a current density of 10 A g−1, high capacity retention ratio up to 90% can be achieved for the composite electrode after 2000 cycles. The outstanding cycling stability can be mainly attributed to rGO-encapsulating structure that effectively prevent the descent of electrical conductivity for the entirety of the electrode during the cycle processes. The ultrahigh specific capacity together with superb cycle performance make such composite a prospective candidate in capacitive energy storage field.

Due to its large specific surface area and extraordinary carrier mobility, graphene has been widely used as the supporting material for metal particles in catalysis. A platinum-based catalyst with a graphene-based porous matrix as the supporting material was prepared by one-step hydrothermal synthesis, which produces a uniform distribution of platinum nanoparticles on the support. This catalyst material shows excellent antipoison ability and superior electrocatalytic stability for the methanol oxidation reaction. It was also found that further annealing treatment could modify the morphology of platinum particles attached to the graphene, and an appropriate annealing temperature contributed to an improvement of its electrocatalytic activity.

Highly ordered TiO2 nanotube arrays were successfully prepared by the combination of the electrodeposition method and the anodic aluminum oxide (AAO) templating method. X-ray diffraction showed that the TiO2 nanotube arrays were of anatase phase. Scanning electron microscopy indicated that the wall thickness of the nanotubes was 20 nm and the external diameter of the TiO2 nanotubes was about 100 nm, which is in good agreement with the pore diameter of the AAO template. Transmission electron microscopy indicated that the TiO2 nanotubes were straight and had uniform thickness along the length. Finally, a possible growth mechanism of the TiO2 nanotube arrays is also discussed.Highlights► TiO2 nanotube arrays are electrodeposited onto the AAO template. ► Outer diameter of the nanotubes is 100 nm and the wall thickness is 20 nm. ► Nanotube formation is decided by the rates of deposition and the diffusion of Ti3+.

Ni–Fe/Cu/Co/Cu multilayered nanowire arrays were electrodeposited into anodic aluminum oxide template by using dual-bath method at room temperature. Scanning electron microscopy and transmission electron microscopy were used to characterize the morphology and structure of the multilayered nanowire arrays. Vibrating sample magnetometer and physical property measurement system were used to measure their magnetic and giant magnetoresistance (GMR) properties. The effect of sub-layer thickness on the magnetic and GMR properties was investigated. The results indicate that magnetic properties of electrodeposited nanowires are not affected obviously by Cu layer thickness, while magnetic layers (Ni–Fe and Co layers) have significant influence. In addition, GMR ratio presents an oscillatory behavior as Cu layer thickness changes. The magnetic and GMR properties of the multilayered nanowire arrays are optimum at room temperature for the material structure of Ni–Fe (25 nm)/Cu (15 nm)/Co (25 nm)/Cu (15 nm) with 30 deposition cycles.Ni–Fe/Cu/Co/Cu multilayered nanowire arrays were prepared by dual-bath electrodeposition method with anodic aluminum oxide template. Two baths were employed to deposit Cu/Co/Cu and Ni–Fe alloy layers separately. The sub-layer with different thickness can be prepared by changing the deposition time. The surface morphology of the electrodeposited multilayered nanowires was observed by scanning electron microscopy and transmission electron microscopy. GMR of the multilayered nanowire arrays exhibits an oscillatory behavior with the change of Cu layer thickness. The maximum room temperature GMR ratio of − 45.2% is achieved when multilayered nanowire structure is Ni–Fe (25 nm)/Cu (15 nm)/Co (25 nm)/Cu (15 nm) with 30 deposition cycles.Download full-size image