Single-crystal manganese oxyhydroxide (MnOOH) nanorods with high aspect ratios have been successfully prepared employing a simple hydrothermal route based on the redox between potassium permanganate (KMnO₄) and polyvinyl pyrrolidone (PVP). By adjusting the reaction temperature, reaction time and the mass ratio of PVP/KMnO₄, MnOOH nanorods with lengths up to 20 μm and diameters in the range of 100–400 nm could be facilely prepared in high yield. The as-prepared MnOOH nanorods were characterised by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and Fourier transformed infrared spectroscopy. The formation mechanism of MnOOH nanorods was preliminarily discussed based on the Ostwald's ripening process. Furthermore, MnO₂ and Mn₂O₃ nanorods with high aspect ratios were synthesised by calcination of MnOOH nanorods.

In this reported work, an acetylcholinesterase (AChE) biosensor based on chitosan-Prussian blue-multiwall carbon nanotubes-hollow gold nanospheres (Chit-PB-MWNTs-HGNs) film was used for detecting pesticide residues in vegetable samples. Three different kinds of sample extraction methods were investigated, such as the oscillation extraction method, the ultrasonication and the centrifugation extraction method and the ultrasonication and filtration extraction method. By comparison, the ultrasonication and centrifugation extraction method was the most appropriate and efficient for the AChE biosensor. After treatment by ultrasonication and centrifugation extraction, the recoveries of the pesticides from vegetable samples were from 76.8 to 105.9% with relative standard deviation lower than 12.68%. Subsequently, the detection results with the AChE biosensor were compared with the standard gas chromatography method. The results indicated that the proposed sample pretreatment method was applicable to the AChE biosensor for pesticide residues detection in real vegetable samples.

Monocrystalline silicon nanowires and nanosheets are prepared in mass production by the novel electroless etching method. Low-cost silicon powders are used as precursors. The initial capacities of silicon nanowires and nanosheets as lithium-ion battery (LIB) anodes are up to 4311 and 4426 mAh/g, respectively. After ten cycles, the reversible capacity maintains 2318 and 2791 mAh/g for nanowires and nanosheets, respectively. The capacity and cyclability of nanosheets is slightly higher than that of nanowires. Such a behaviour is attributed to their finite lateral sizes and enhanced open-edges, which can facilitate Li ion diffusion and decrease overvoltage associated with Li–Si alloying reaction. The presented results open a way for synthesising silicon nanostructures as LIB anodes in mass production and low cost.

Ag₂O/Ag₃PO₄ heterostructures photocatalysis was prepared for the first time. Photocatalytic tests displayed that the Ag₂O/Ag₃PO₄ heterostructures possessed a much higher degradation rate of methyl orange and phenol than pure Ag₃PO₄ under visible light. The enhanced photocatalytic activity could be attributed to effective separation of photogenerated carriers driven by photoinduced potential difference generated at the Ag₂O/Ag₃PO₄ heterojunction interface. Repetitive tests showed that the Ag₂O/Ag₃PO₄ heterostructures maintained high stability over several cycles, and it had better regeneration capability under mild conditions. The good stability could be attributed to the protection of insoluble Ag₂O nanoparticles on the surfaces of Ag₃PO₄ crystals in aqueous solution.

In this reported work, TiO₂ nanoparticles containing anatase-rutile and pure rutile phases were prepared by sol–gel and hydrolysis in acidic solution methods, respectively. Two general procedures, doping during synthesis (DDS) via a hydrolysis method and doping on the provided TiO₂ nanoparticles (DOP) that is performed by the impregnation method have been studied by doping copper to these nanoparticles. The photocatalytic activity was evaluated by photodegradation of C.I. Acid Red 27 as a model contaminant. The prepared samples were characterised by X-ray diffraction, atomic absorption flame emission spectroscopy and scanning electron microscopy. It is found that the photosensitised degradation activity can be enhanced by doping an appropriate amount of Cu. Photocatalytic activity results indicated that samples that have been doped by the DDS procedure show higher photocatalytic efficiency than samples doped by the DOP procedure.

Nearly monodispersed Fe/SiO₂ yolk/shell nanospheres with an average diameter of about 250 nm were synthesised by hydrogen-thermal reduction of Fe₃O₄/SiO₂ precursor nanospheres. The morphology of products and precursors was characterised in three stages of preparation. Electrical conductivity magnetic properties and electromagnetic properties in the microwave band of Fe/SiO₂ yolk/shell nanospheres were investigated. The eddy current effect in Fe/SiO₂ yolk/shell nanospheres was effectively suppressed because of separation of ultrafine iron particles by silica shells, indicating that the eddy current effect can be suppressed only by separating iron particles and it is not related to the interface of iron and sillica. A reflection loss of −12.5 dB and an effective absorption band with a bandwith of 3.3 GHz were simultaneously obtained for Fe/SiO₂ yolk/shell nanospheres-containing coatings with thickness of 2 mm. Compared with bare Fe particles obtained from Fe₃O₄ precursor nanospheres, oxidation resistance of Fe/SiO₂ yolk/shell nanospheres was improved because of the existence of silica shells.

AgBr/Ag₃PO₄ composite quasi-microcubes were fabricated by a simple ultrasonic synthesis method, in which hexadecyltrimethylammonium bromide was used as Br resource and surfactant. The structures and morphologies of the as-obtained product were initially characterised by X-ray diffraction, field emission scanning electron microscopy and energy dispersive X-ray analysis spectroscopy. The ultraviolet–visible diffuse reflectance spectrum of the as-obtained products demonstrated that this hybrid structure exhibits an enhanced absorption ability in the visible region. Furthermore, the composite products exhibit much higher photocatalytic performance and stability on degradation of rhodamine B dye under the stimulated sunlight irradiation compared with pure AgBr and Ag₃PO₄.

Biomaterials usually require simultaneous possession of excellent performances such as bioactivity, mechanical and bio-tribological properties to meet biomedical application requirements. In this reported work, the bioactive and mechanical properties of biocomposites were simultaneously optimised according to the functional gradient design idea. The functional gradient nano-hydroxyapatite reinforced polyetheretherketone (nano-HA/PEEK) biocomposites were fabricated through the layer-by-layer casting method and incorporation with thermal pressure moulding technology. The microstructure and morphology were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). The result of the XRD study verified that the crystallinity of the PEEK matrix obviously improved after heat treatment. The SEM observation revealed that the size of HA particles in the biocomposites was in the nanometre scale. Furthermore, two typical morphologies such as encapsulated- and dimple-like microstructures were observed by SEM. The FTIR study showed that the interaction between nano-HA particles and the PEEK molecule existed. Both the SEM and FTIR studies results revealed that the morphology and microstructure in the functional gradient HA/PEEK biocomposites were beneficial for the improvement of the mechanical properties of the gradient biocomposites.

A study has been conducted on patterned graphene with widths in the range of 0.1–4 μm which was grown by chemical vapour deposition and patterned by electron beam lithography. The microscopic behaviour of the Raman spectrum was investigated using image mapping from Raman spectroscopic data. Among three main peaks (D-band, G-band and 2D-band), the two-dimensional (2D) peak was clear even in 200 nm width graphene, however the D-band signal was very weak, confirming low defect concentration. It was found that the 2D-band line width was decreased as the width became narrower, which was explained by refining the electronic band structure because of confined sample size. The 2D- and G-band intensities were decreased by reducing the width because the laser beam spot size was greater than the width of the sample and the effective area generating the signal was reduced.

The purely acrylic latex with submicro particle size was prepared via semi-continuous seeded emulsion polymerisation of butyl acrylate and methyl methacrylate in water phase initiated with potassium persulphate and emulsified with mixed surfactants of sodium dodecyl benzene sulphonate and allyloxy nonylphenoxy propanol polyoxyethylene ether (ANPPE). The structure of the resultant latex is confirmed with Fourier transform infrared spectroscopy spectrum. Differential scanning calorimetry also confirms that the resultant latex is a type of random copolymer and the consistency among the chain segment is fairly good. Influences of the amount of ANPPE on the properties of the resultant latex and its film were investigated in detail. Results show that the contact angle of the film first is increased and then decreased with the increase of the amount of SN-10. The glass transition temperature of the film is decreased with the increase of the amount of SN-10. However, the particle size of the latex is increased with the increase of the amount of SN-10.

Metal-enhanced fluorescence (MEF) is a powerful technology to improve the sensitivity of fluorescence analysis by allowing fluorophores to interact with enhanced electromagnetic fields generated by the localised surface plasmon resonance effects of metallic nanostructures. To apply MEF technology to disposable DNA or protein microarray analysis, metallic nanostructures need to be fabricated on the full area of a glass slide at low cost. In this reported work an oblique angle deposition process was used to fabricate Ag nanorods on the whole area of a 25 × 75 mm² glass slide to serve as an inexpensive and large-area MEF substrate. To examine the feasibility of the proposed substrate and maximise signal enhancement, Ag nanorods with different lengths were deposited on glass slides. Different concentrations of streptavidin-conjugated Cy5 in phosphate buffered saline were spotted onto the Ag nanorods and bare glass substrates, and the fluorescence signals were measured and compared. Longer Ag nanorods improved the fluorescence enhancement factor because of a higher surface plasmon resonance effect and the large surface area of the nanostructure with a high aspect ratio. A maximum enhancement factor of −23 was obtained from Ag nanorods that were 1000 nm long with comparable uniformity with the glass substrate.

Ni and Co doped nanocrystalline BiFeO₃ (BFO) have been prepared using a facile sol–gel technique. The effects of codoping on the crystal structure, morphology and electrical properties are investigated. X-ray diffraction and high-resolution transmission electron microscopy studies confirm the phase purity and growth of BFO nanoparticles. The heat-flow measurement using a differential thermal analyser shows an endothermic peak between 1070 and 1100 K representing ferroelectric to paraelectric phase transition. A systematic electrical conductivity study of these nanoparticles delineates that resistivity increases for doped BFO samples which is very much desirable for device applications of multiferroics.

Sheet-like ZnO Ag/ZnO composites were synthesised by calcination of each precursor prepared via a hydrothermal treatment. The samples were characterised by thermogravimetric analysis and differential thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy technologies. The results showed that ZnO and Ag/ZnO composite nanosheets were composed of nanoparticles. The electrocatalytic performances of the samples modified on a glassy carbon electrode for p-nitrophenol, K₂CrO₄ and H₂O₂ reduction in a basic solution, respectively, were investigated using a cyclic voltammetry method. The results revealed that ZnO and Ag/ZnO composites with Ag content from 1 to 5% all exhibited an enhanced catalytic activity by comparing with a bare glassy carbon electrode. Among the samples, Ag/ZnO composite with 4% Ag displayed the highest catalytic activity for p-nitrophenol, and H₂O₂, but the one with 3% Ag content showed the highest catalytic activity for K₂CrO₄ reduction.

Hexagonal magnetite (Fe₃O₄) nanoplates were synthesised using a facile hydrothermal route, where ß-cyclodextrin and urea were used as a reducing agent and a modifier, respectively. It was found that the obtained hexagonal Fe₃O₄ nanoplates had an average diameter of about 400 nm and thickness in the range of 40–80 nm. The effects of the concentration of urea and pH value on the formation of Fe₃O₄ nanoplates are discussed. A possible formation mechanism for the hexagonal Fe₃O₄ nanoplates is proposed. Magnetic studies revealed that the hexagonal Fe₃O₄ nanoplates exhibited a relatively high saturation magnetisation of 78.93 emu/g and a coercivity of less than 200 Oe at room temperature, which indicates that the as-prepared Fe₃O₄ nanoplates are ferromagnetic.

This Letter presents a novel small-sized lateral insulated gate bipolar transistor on silicon-on-insulator substrate (SOI-LIGBT), which features a lowly doped p-type pillar alongside the oxide trench in the drift region. The variation in vertical doping termination technology is also proposed for the first time. The p-pillar layer leads to electric field reshaping in the y-direction, and homogenises current flow lines under the gate and cathode. It results in a very wide forward bias safe operating area (FBSOA) for the proposed SOI-LIGBT, which is obviously improved by over 50% compared with the deep-oxide trench SOI-LIGBT (DT SOI-LIGBT). Moreover, at the same forward voltage drop of 1 V, the turnoff energy loss for the proposed SOI-LIGBT is reduced by 28.5 and 81.2% compared with those of DT SOI-LIGBT and the conventional SOI-LIGBT, respectively.