The photoluminescence (PL) properties corresponding to different types of the interstitial clusters (or defects) in the silicon ion (Si⁺) self-implanted Si have been well reviewed. Given a brief of the conjectural origin, defect type, annealing temperature of the W (1218 nm), X (1193 nm) peak, R (1376 nm), and D bands concluded the present application of Si⁺ self-ion-implantation. The challenges for application of light-emitting Si and application prospects are also discussed.

To study the performance of pure aluminium (Al) oxide film produced by high-speed wire electrical discharge machining (WEDM-HS), some characterisation indices including phase composition, surface morphology characteristics, roughness, friction coefficient, oxide content and thickness of the 1060 Al oxide film are researched, respectively, through X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscope, confocal microscope, contourgraph and nanoindentation. The results show that the produced oxide film of 1060 Al is mainly composed of Al₂O₃ phase after the 1060 Al sample processed by WEDM-HS. With the pulse width of WEDM-HS is gradually decreasing, the Al₂O₃ content values in the oxide film are all more than 84% with slight change. The surface morphology of the oxide film is made up of honeycomb holes of microns size. Moreover, the ladder-like microstructures of square bracket are found for the first time at the inside wall from bottom to top of the microholes. With the decreasing of the pulse width, the thickness and the friction coefficient of the oxide film first decrease, then increase and finally tend to be stable. They both have certain relationships with the Al₂O₃ content of the oxide film.

Y₂O₃ microspheres were obtained via homogeneous precipitation method. Y₂O₃ microspheres with different sizes and morphologies were prepared by adjusting the reaction temperature, the concentration of ytterbium nitrate and urea (H₂NCONH₂), and the amount and species of surfactants. The structure and morphology of the as-obtained Y₂O₃ were analysed by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the results showed that the sample showed the optimal microscopy when it was prepared at 80°C with the concentration of ytterbium nitrate, H₂NCONH₂ and betaine fixed at 0.01 M, 0.04 M and 4 g/l, respectively. Moreover, the as-prepared samples were uniform and smooth-surfaced.

A novel enzymeless glucose sensor based on nickel oxide (NiO) nanoparticles electrodeposited on reduced graphene oxide–copper oxide nanocomposite bulk modified carbon ceramic electrode (rGO–CuO/CCE) was reported. The prepared NiO/rGO–CuO/CCE was characterised by scanning electron microscopy, energy-dispersive X-ray spectroscopy, atomic-force microscopy, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry techniques. Electrocatalytic performance of the NiO/rGO–CuO/CCE was investigated in details for the electro-oxidation of glucose using cyclic voltammetry and amperometry techniques. The developed sensor responds efficiently to glucose over the concentration range 5–920 µM with the detection limit 2.63 µM and sensitivity 5980 µA mM⁻¹ cm⁻². According to EIS studies, ternary presence of rGO, CuO and NiO nanoparticles increased the electron transfer performance and sensitivity of NiO/rGO–CuO/CCE to glucose. The prepared sensor was applied for the determination of glucose in human serum samples with satisfactory results. Owing to renewable and polishable surface, high sensitivity, reproducible responses and long-term stability, the developed sensor could be used in clinical applications.

In the present study, tri-sodium citrate has been used as both the reducing agent and stabiliser for the synthesis of silver nanoparticles (AgNPs). Sodium borohydride (NaBH₄) was used in various concentrations. The absorbance of AgNP solution was measured after the addition of NaBH₄. The samples were characterised by ultraviolet-visible spectroscopy after 5, 10, 15, 25, 60 and 120 min of synthesis to investigate the stability of AgNPs for different concentrations of NaBH₄. Transmission electron microscopy revealed the nanostructure of the prepared samples with average sizes as 18, 20 and 29 nm. Photoluminescence spectra of these AgNPs showed maximum emission at wavelengths 473, 470 and 469 nm, respectively, when excited at 350 nm. Further, Disk diffusion test showed that all the prepared samples are good candidates for antibacterial activity while AgNPs of average size 18 nm were found most effective against the tested Gram-positive and Gram-negative bacteria.

Core–shell structured composites of Zn-doped CoFe₂O₄ cubes @CNTs were in situ synthesised using a CVD method at 450°C with Zn-doped CoFe₂O₄ cubes as catalysts and ethanol as carbon source. The as-obtained products were characterised using an X-ray diffractometer, transmission electron microscope, thermogravimetric analyser and vibrating sample magnetometer. Results demonstrated that CNTs uniformly grew on the surface of Zn doped CoFe₂O₄ cubes to form the shell with average diameter of 20–80 nm. The average diameter of the core/shell Zn-doped CoFe₂O₄ @CNTs cubes range from 3 to 10 µm. The magnetic hysteresis curves of Zn-doped CoFe₂O₄ cubes @CNTs illustrated the strong magnetic response to a varying magnetic field and the saturation magnetisations for the composites obtained at 450 and 600°C were 33.55 and 10.05 emu g⁻¹, respectively. A minimum reflection loss of −9.98 dB was observed at 9.2 GHz for the Zn-doped CoFe₂O₄@CNTs core/shell composites with a thickness of 2 mm. The Zn-doped CoFe₂O₄@CNTs core/shell composites prepared at a higher temperature exhibited better microwave absorbing performance than the sample prepared at a lower temperature.

Water hyacinth-based activated carbon (denoted as WHc) decorated with porous petaloid-like nano-NiO has been fabricated by hydrothermal method. The hierarchical petaloid-like NiO composed of numerous nanoplates is uniformly covered on the surface of WHc. Such unique nanocomposite exhibits excellent electrochemical performances: a high specific capacitance of 249.5 F g⁻¹, a good rate capability and an excellent cycling performance with 78.35% retention after 1000 cycles can be obtained at a current density of 1 A g⁻¹. These results suggest that the porous petaloid-like WHc/NiO nanocomposite (denoted as WHc/NiO) may be promising for practical applications for supercapacitors.

Carbon nanorods (CNRs) have been attracting increasing interest because of their potential applications in high-performance nanoscale materials and electronic devices. Among the many preparation methods, the nanocasting method via inorganic template materials exhibited a controllable and facile feature. This work was to present a novel preparation of CNRs through the nanocasting method using halloysite nanotubes (HNTs) as the template and polyvinyl alcohol (PVA) as the nanocasting carbon source. For the sake of PVA nanocasted in the hollow structure of HNTs, we adopted the repeated soakage method. The forming process and structure of CNRs were revealed by XRD, FT-IR, SEM, TEM, SAED XPS, Raman and Brunner–Emmet–Teller (BET) characterisation techniques. The results showed that the as-obtained CNRs with the rod-like structure had a high specific surface area of ca. 284 m²/g and exhibited typical mesoporous features.

In this work, the performance estimation of polarity controlled electrostatically doped tunnel field-effect transistor (TFET) is reported. The proposed device exhibits heavily doped n-type Si-channel with two distinctive gates, namely control gate (CG) and polarity gate (PG). First, the CG and PG work functions of 4.72 eV are considered to convert the layer beneath CG and PG of intrinsic type. Next, the PG voltage of −1.2 V is used at source side to induce a p+ region, so that, it follows the similar trend as like a n ⁺ –i–p ⁺ gated structure of conventional TFET. Silvaco ATLAS simulation of the proposed device shows I _ON/I _OFF ratio of ∼7.8 × 10¹⁰ and OFF current is less than 1 fA, with high-k dielectric of gate material at V _DS = 0.5, V. Finally, a minimum point subthreshold slope of 12 mV/decade at 300 K is achieved, which indicates that the proposed TFET has the potential to achieve better than ITRS low-standby-power switch performance.

The green synthesis of gas-sensing materials, which monitor volatile organic compounds, avoid synthesis-induced pollution, and thus is a major challenge faced by scientific researchers. Herein, we report a microwave-assisted green synthesis of Ag-decorated SnO₂ nanorods with water being used as solvent and comparatively non-toxic chemicals being used as reactant. The as-prepared product was characterised by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed one-dimensional Ag-decorated SnO₂ nanorods constituted of tetragonal rutile phase of SnO₂ and cubic phase of Ag were successfully prepared. Ethanol was used as a model system for measuring gas-sensing properties and an enhanced gas-sensing property was found due to Ag decoration. Moreover, a linear dependence of the sensitivity on the ethanol concentration was observed.

Mesoporous SiO₂/Zn₂SiO₄:Eu³⁺ hollow nanospheres were successfully synthesised via the combination of layer-by-layer and combustion technique. The structures and morphologies of as-obtained SiO₂/Zn₂SiO₄:Eu³⁺ nanospheres were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N₂ adsorption–desorption isotherms techniques. SiO₂/Zn₂SiO₄:Eu³⁺ nanospheres can be tested as adsorbents to remove heavy metal ions, which showed good adsorption capacity and selectively adsorption especially for Pb²⁺ and Cu²⁺ than Cd²⁺. The optical properties studies of as-synthesised samples showed that mesoporous SiO₂/Zn₂SiO₄:Eu³⁺ hollow nanospheres had strong red emission around 618 nm, and the optimal loading dosage of Eu³⁺ was determined. Moreover, the mesoporous SiO₂/Zn₂SiO₄:Eu³⁺ hollow nanospheres could offer cell optical imaging by conventional fluorescence with 543 nm excitation.

Three-dimensional vertical graphene flowers were fabricated using a simple, low-cost, and efficient chemical vapour deposition method with Ni(NO₃)₂ as a catalyst precursor and methane as a carbon precursor. Graphene flowers of up to 10 μm in size with petals of two to seven layers of graphene were obtained. The growth of the vertically aligned graphene flowers was attributed to a columnar growth mechanism. Numerous micropores were observed between the flower petals and irregular mesopores were observed in the interconnected flowers. The charge-transfer resistance of a graphene flower/Ta film was 30.8 Ω. The graphene flowers acted as charge carriers, reducing the charge recombination rate and enhancing electron transport. The vertical graphene flowers showed significant photoelectrocatalytic activity for the degradation of phenol.

The buckling analysis of a cantilever single-walled carbon nanotube embedded in an elastic medium with an attached spring is researched. The effects of axial compression load, attached spring, small size and surrounding elastic medium are taken into account at the same time. Theoretical formulation is carried out on the basis of the Bernoulli–Euler beam theory in conjunction with Eringen's non-local elasticity theory. Fourier sine series is selected for the simulation of single-walled carbon nanotube deflections. Winkler elastic foundation type is used to simulate the interaction between single-walled carbon nanotube and elastic medium. 2 × 2 coefficient matrix is derived with the aid of applying Stokes’ transformation to corresponding non-local boundary conditions. The critical buckling loads are calculated by using this coefficient matrix. Different validation studies are performed to endorse and corroborate the usefulness of the presented analytical method.

This work reports the fabrication of magnetic hollow nanotubes with hierarchical nickel silicate shells and superparamagnetic iron oxide cores. The as-prepared magnetic hierarchical hollow nanotubes possess a tailored complex wall structure, high surface area. In particular, the magnetic property of hierarchical double-walled hollow nanotubes makes it easy to recycle for reuse. Furthermore, the effective procedure is general for development other metal silicate materials with hierarchical hollow nanotubes morphology.

The development of Earth-abundant low-cost catalyst materials for effective water oxidation is of critical importance for electrochemical hydrogen production. The first use of hydrothermally in situ grown cobalt carbonate hydroxide hydrate nanowires array on carbon cloth as an effective catalyst electrode for water oxidation in alkaline electrolytes is described. This three-dimensional electrode shows high catalytic activity with the need of overpotential of 323 mV to drive 10 mA cm⁻², and its activity can be retained for at least 40 h.

To explore the application of miniaturised polarisers into the detection of the skylight polarisation angle, a fabrication process for single-layer metallic nano-gratings, which was treated as polarisers in the polarised light testing instrument, was proposed. With the help of the combination of two efficient fabrication methods, the nanoimprint lithography and the lift-off method, different directions of the metallic gratings with 200 nm period, 110 nm linewidth and 60 nm height were fabricated simultaneously on the substrate. An interval ultrasound method is proposed to avoid grating structure damage during the lift-off process. Additionally, the effect of the SiO₂ layer addition during the etching process on the transmission performance of metallic gratings is presented by a brief theory analysis and experiment results. The fabricated grating is installed on the designed testing instrument to measure the angle of polarised light and the final angle output error is within ±0.25°, which demonstrates that the fabricated metallic gratings have a good prospect as a polaroid applied in the polarisation navigation.

The effect of gamma-ray (γ-ray) irradiation on the material characteristics of nanometre scale films of molybdenum disulphide (MoS₂) has been investigated. 3.2, 4.5, and 5.2 nm thick MoS₂ films (measured by atomic force microscopy) were grown on Si by using a two-step synthesis method (sputtering of Mo, followed by sulphurisation). The samples were subsequently exposed to γ-ray irradiation (dose of 120 MRad). Dramatic chemical changes in the MoS₂ films after irradiation were characterised by micro-Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and optical microscopy. Micro-Raman spectroscopy showed the disappearance of the E _2g ¹ and A _1g modes after irradiation. XPS revealed that the MoS₂ crystal structure was converted to molybdenum oxide (MoO _x ). It is hypothesised that S vacancies are formed due to the γ-ray irradiation, which subsequently transforms MoS₂ to MoO _x .