Ce-doped Zn-Al layered double hydroxide (LDH) nanocontainer was synthesized by a co-precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods were used for the characterization of the LDH nanocontainer. The anticorrosion activity of the LDH powders embedded in a hybrid sol-gel coating on aluminum alloy 2024 was investigated by electrochemical impendence spectroscopy (EIS). The results showed that Ce (III) ions were successfully incorporated into LDHs layers. The sol-gel coating modified with Ce-doped Zn-Al LDHs exhibited higher anticorrosion behavior compared with both unmodified and Ce-undoped LDHs containing coatings, which proved the applicability of Ce-doped LDHs in delaying coating degradation and their potential application as nanocontainers of corrosion inhibitors in self-healing coatings.

•3D reduced GO framework (NHGF) with unique hierarchical pores is synthesized.•The compressed NHGF paper is used as free-standing counter electrode for DSSC.•The DSSC performance with NHGF paper CE is 5.56% and is higher than using Pt (5.45%).Three-dimensional nitrogen doped holey reduced graphene oxide framework (NHGF) with hierarchical porosity structure was developed as high-performance metal-free counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). With plenty of exposed active sites, efficient electron and ion transport pathways as well as a high surface hydrophilicity, NHGF-CE exhibits good electrocatalytic performances for I−/I3− redox couple and a low charge transfer resistance (Rct). The Rct of NHGF-CE is 1.46 Ω cm2, which is much lower than that of Pt-CE (4.02 Ω cm2). The DSSC with NHGF-CE reaches a power conversion efficiency of 5.56% and a fill factor of 65.5%, while those of the DSSC with Pt-CE are only 5.45% and 62.3%, respectively. The achievement of the highly efficient 3D structure presents a potential way to fabricate low-cost and metal-free counter electrodes with excellent performance.

Highly ordered polyaniline nanocone arrays were synthesized on three-dimensional graphene network by template-free electrodeposition method. The morphology of the material was characterized by scanning electron microscopy. The structural features were analyzed by using Raman spectroscopy. Polyaniline nanocones align vertically on the surface of three-dimensional graphene network. Such morphology provides unblocked diffusion path for electrolyte ions, and increases the specific area of the material. The material possesses specific capacitance of 751.3 F g−1 in 1 M HClO4 within the potential window of 0–0.7 V, and has high rate capability as well as good cycling stability. At a current density of 10 A g−1, its capacitance is 88.5% of that at a current density of 1 A g−1. Furthermore, the material remains 93.2% of initial capacitance after 1000 cycles of charging–discharging test.

The performances of photovoltaic devices can be improved by increasing light-harvesting and charge collection respectively. The design and synthesis of nanocomposites with the ability of enhancing the generation and collection of the photo-generated electrons provide a significant way to improve the power conversion efficiency (PCE). Herein, SWNTs@(TiO2/Ag/Au) nanocomposites were synthesized and successfully integrated into photoanode films of dye-sensitized solar cells (DSSCs) to improve the power conversion efficiency. The synthesis processes were based on multi-functional DNA. DNA not only works as a dispersing agent preventing SWNTs bundling but also as a sacrificial mold assembling TiO2, Ag and Au nanoparticles on the surface of the SWNTs. The synthesized SWNTs@(TiO2/Ag/Au) nanocomposites enhance the charge collection and light-harvesting of DSSCs simultaneously. With 2.45 wt% SWNTs@(TiO2/Ag/Au) nanocomposites incorporating into the photoanode films, the PCE of the DSSCs increases from 6.8% to 8.3%.

•ZnAlCe-LDHs were synthesized in the presence of different concentrations of Ce.•Ce (III) was successfully inserted into the sheets of LDH.•Two phases were formed when Ce/(Al + Ce) atomic ratio was higher than 0.05.•ZnAlCe-LDH nanoparticles were embedded into sol–gel film on aluminum alloy.•The anticorrosion property of coating system was enhanced after embedding LDHs.A protective coating was designed by dispersing Ce-doped ZnAl layered double hydroxides (ZnAlCe-LDHs) nanoparticles in hybrid sol–gel (SiOx/ZrOx) layer on aluminum alloy AA2024. The concentration of cerium in synthesized LDHs was varied to ascertain the optimum condition for anticorrosion performance. The LDH nanoparticles were characterized in terms of structure, morphology and chemical composition. It was found that Ce (III) was inserted into the sheets of LDHs and two mixture phases of LDHs and CeO2 were formed when the atomic ratio of Ce/(Al + Ce) was higher than 0.05. The sol–gel coating embedded with LDHs (Ce/(Al + Ce) = 0.1) exhibited high corrosion resistance, probably due to the synergistic inhibition of ZnAlCe-LDHs and CeO2 nanoparticles.

The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25°C and a constant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the approximate ranges of 10–20 nm and 5–10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.

ZnAl layered double hydroxide (LDH) host films have been synthesized on aluminum alloy 2024 substrate via a facile crystallization method, and then intercalated with different corrosion inhibitor anions (vanadate, molybdate, and 2-mercaptobenzothiazolate). The structures, compositions, and morphologies of the as-synthesized films before and after the anion-exchange reaction were characterized by means of glancing-angle X-ray diffraction, Fourier transform infrared, X-ray photoelectron spectroscopy, and scanning electron microscope techniques. The anticorrosion performance of films was evaluated by potentiodynamic polarization and salt spray test. The results show that all inhibitor anions are successfully intercalated in the layered galleries, providing enhanced corrosion protection for the substrate alloy. The anticorrosion abilities of films loaded with inhibitor anions are ordered as LDH–VO3 > LDH–MBT > LDH–MoO4 > LDH–NO3.

A highly oriented LiAl-layered double hydroxide (LDH) film was first fabricated via a facile in situ growth method on Al–Li alloy. The morphology and structure of the LDH film were characterized using scanning electron microscopy, atomic force microscopy, X-ray diffraction, and transmission electron microscopy. After chemical modification with 1H,1H,2H,2H-Perfluorodecyltrimethoxysilane, the chemical compositions and states of surface-modified film were analyzed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The results showed that the nest-like structure of LiAl-LDH film was composed of interconnected LiAl-LDH nanosheets, which oriented almost vertically to the substrate surface. After chemical modification, a superhydrophobic surface was obtained with water contact angle of 168°. The formation mechanism of the superhydrophobic film was also discussed.

The influence of rust layers on the corrosion behavior of ultra-high strength steel 300M subjected to a simulated coastal atmosphere was investigated by corrosion weight loss, surface analysis techniques, and electrochemical methods. The results exhibit the presence of a large proportion of γ-FeOOH and α-FeOOH and a small amount of Fe3O4 in the outer rust layer. During the wet–dry cyclic process, the bonding performance and the density of outer rust layer deteriorate with the thickness of outer rust. The inner rust layer plays a main role on protectiveness, which can be attributed to the formation of an ultra-dense and adherent rust film with major constituent of α-FeOOH and α-Fe2O3 on the steel.

The effects of chloride, sulfate and carbonate anions on stress corrosion behaviors of ultra-high strength steel 23Co14Ni12Cr3Mo were studied by stress corrosion cracking (SCC) test method using double cantilever beam (DCB) specimens. The SCC morphology was observed by using scanning electron microscopy (SEM) and the composition of corrosion products was analyzed by using energy dispersive spectrometer (EDS). The results show that the crack propagates to bifurcation in NaCl and Na2SO4 solution, while the crack in Na2CO3 solution propagates along the load direction. The SCC rate in NaCl solution is the highest, while lower in Na2SO4 solution and little in Na2CO3 solution. From the SEM morphologies, quasi-cleavage fracture was observed in NaCl and Na2SO4 solutions, but intergranular features in Na2CO3 solution. The mechanism of anion effect on SCC of steel 23Co14Ni12Cr3Mo was studied by using full immersion test and electrochemical measurements.

The aging properties of advanced composite T300/5405 which soaked in 15# hydraulic oil, 4010 lubricating oil, RP-3 kerosene and AHC-1 cleaner were studied. The absorption and mechanical properties of the composites were measured, and the scanning electron microscopy (SEM), dynamic mechanical analysis (DMA) and the infrared analysis (IR) were used to investigate the properties’ changes of the composite. The aging mechanism of composite T300/5405 was also discussed. The experimental results show that the absorption of the composite in AHC-1 was the biggest, and the other three mediums had little effect on the composites. The mechanical properties declined in the aging. The composites have undergone chemical change in the test; Tg rose or declined after the aging, and the AHC-1 cleaner and 4010 lubricating oil had the greatest influence on the Tg.

The performances of photovoltaic devices can be improved by using high electron mobility nanocomposites to increase charge collection and transportation. Single-walled carbon nanotubes (SWNTs) exhibit high electron mobility and are believed to be promising materials to enhance the power conversion efficiency of photovoltaic devices. Herein, we present DNA applied as a biological scaffold to fabricate SWNTs/TiO2 and SWNTs/TiO2/Ag nanocomposites, which are integrated into photoanode films to achieve high efficiency dye-sensitized solar cells (DSSCs). The effects of the amounts of SWNTs and Ag NPs in photoanode films on the performances of DSSCs are investigated. After incorporating the nanocomposites into photoanode films, the power conversion efficiency is enhanced. In particular, when the amounts of SWNTs and Ag NPs in the photoanode are 0.15 wt% and 0.8 wt%, the DSSC exhibits a high power conversion efficiency of ∼5.99%, ∼37.07% improvement compared with conventional TiO2-only DSSCs. The mechanisms of the performance improvement are discussed in detail.

Dye-sensitized solar cells (DSSCs) are attracting increasing attention as a promising technology for renewable energy production, and the localized surface plasmons (LSPs) of metal nanoparticles (NPs) is being actively explored to enhance the performance of DSSCs. Herein, plasmid DNA was employed as a bioscaffold to fabricate Ag@TiO2 plasmonic nanocomposites for DSSCs. The effect of the nanocomposites on the light harvesting and the dependence of the amount of the nanocomposites in the photoanode on the performance of plasmonic DSSCs were investigated. It was found that plasmid DNA not only worked as a scaffold to drive the formation of the nanocomposites, but also acted as an effective reducing agent under the UV irradiation. Due to the nanocomposites working as “plasmonic components” in the photoanode, compared with conventional TiO2-only DSSCs, the light harvesting, corresponding photocurrent, and power conversion efficiency (PCE) were enhanced in the presence of the nanocomposites. Specially, when the amount of Ag NPs in the plasmonic photoanode was 0.8 wt%, the PCE was 1.83%, increased by ∼28.87% compared with 1.42% for the TiO2-only DSSC. Additionally, plasmonic DSSCs reduced the materials required by ∼30% for DSSC fabrication to maintain the same performance as conventional TiO2-only DSSCs.

Pd nanoparticles were introduced to individual Bacillus cells and dispersedly anchored on both the inside and outside of the cell walls. The anchored nanoparticles served as “seeds” to drive the formation of double metallic layers forming a metal–cell wall–metal sandwich structure at the single-cell level.

Polyaniline (PANI) nanofiber is grafted onto graphene to obtain a novel graphene-polyaniline (GP) hybrid. Graphene is activated using SOCl2 and reacts with PANI to form an amide group that intimately connects graphene and PANI. The existence of the amide group and its anchoring effect in the GP hybrid are confirmed and characterized by SEM, TEM, FT-IR, Raman, XPS and quantum chemistry analyses. Electrochemical tests reveal that the GP hybrid has high capacitance performances of 579.8 and 361.9 F g–1 at current densities of 0.3 and 1 A g–1. These values indicate superiority to materials interacted by van der Waals force. Long-term charge/discharge tests at high current densities show that the GP hybrid preserves 96% of its initial capacitance, demonstrating good electrochemical stability. The improved electrochemical performance suggests promising application of the GP hybrid in high-performance supercapacitors.Keywords: amide; graphene; polyaniline nanofiber; supercapacitor;

The metallic Cu spiral with length of 200–300 μm was prepared based on spirulina bioscaffold. The electroless deposition approach was applied to cover the catalyzed spirulina forming the spiral. The morphology, composition and structure of the resulting spiral were characterized by using scanning electron microscopy (SEM), energy dispersive analysis (EDS) and X-ray diffraction (XRD). It was found that the spirulina was successfully covered with uniform Cu coating with face-centered cubic (FCC) structure, and the obtained spiral maintained the original shape of spirulina. It was suggested that this approach could be also utilized to prepare other metallic spiral such as Co, Ag or other alloys to vary the magnetic, electrical or physical properties, and the obtained spiral could be promising material as functional micro-springs and micro-devices for microelectromechanical systems (MEMS) studying.Highlights► The spirulina was successfully employed as biotemplate to prepare the metallic Cu spiral. ► The electroless depositing method was applied to coat the spirulina forming the metallic spiral. ► The length and diameter of the resulting spiral were 200–300 μm and ~15 μm, respectively.

Ag–Ni nanorings were synthesized by using toroidal topology Plasmid DNA with 7500 base pairs as templates. The photoirradiation method was employed to reduce metallic cations and deposited on the Plasmid DNA forming nanorings. The Plasmid DNA was separated from Bacillus hosts by using molecular biology methods. The morphology, composition, and structure of the nanorings were characterized by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS) and selected-area electron diffraction (SAED). The UV–vis spectrum was applied to study the different stages of the synthesis processes. It was found that the Ag–Ni was successfully deposited on the surface of the Plasmid DNA and formed the nanorings. The nanorings exhibit monodispersity and with an outer diameter of ~ 50 nm and an inner diameter of ~ 30 nm. It was suggested that this approach has promising application for the synthesis of other metal or alloy nanorings.Highlights► Ag-Ni nanorings were synthesized by using toroidal topology Plasmid DNA with 7500 base pairs as templates. ► The photoirradiation method was employed to reduce metallic cations and deposited on the Plasmid DNA forming nanorings. ► The nanorings exhibit monodispersity and with an outer diameter of ~50 nm and an inner diameter of ~30 nm.

Bioinspired synthesis approaches aim to take advantage of the morphology and structural features of biological materials for the development of functional micro/nanodevices. In this Letter, we report that a unicellular algae known as a Spirulina was applied as a bioscaffold for the synthesis of hollow metallic Cu microspirals with length of 200–300 μm. The electroless deposition method was employed to cover the spirulina forming the spiral. The nanomechanical properties of the spiral were investigated by using the nanoindentation technique. The results showed the hardness and elastic modulus of the spiral were 0.63–0.68 GPa and 12.35–12.63 GPa, respectively. Other metallic or alloy spirals could also be synthesized by using the spirulina as a bioscaffold with low cost and high reproducibility, and the obtained spirals could be promising materials as functional micro/nanodevices for microelectromechanical systems.

Unlike conventional routes for preparing graphene/polyaniline (G/PANI) composites coupled by van der Waals forces, an approach to graft polyaniline (PANI) nanofibers onto graphene to acquire a polyaniline–graphene (PANI–G) hybrid connected by amide groups is described in this study. The chemical bonding between graphene and PANI is confirmed by infrared spectroscopy and X-ray photoelectron spectroscopy. The Raman spectrum of PANI–G hybrid demonstrates a close interaction between graphene and PANI. Electrochemical tests show that PANI–G hybrid has a high capacitance (623.1 F/g) at a current density of 0.3 A/g, higher than that in G/PANI composites reported previously. In addition, the retained capacitance of the PANI–G hybrid in the long term charge/discharge cycling test reached as high as 510 F/g at a current density of 50 A/g, suggesting its potential use in supercapacitors. First-principle calculations were carried out to study the electronic structures of PANI–G hybrid. The results show that the carbonyl group in the amide linkage plays a key role in the formation of π-conjugated structure, facilitates charge transfer, and consequently improves capacitance and cycling ability.

The chemical stripping method of titanium alloy oxide films was studied. An environment friendly solution hydrogen peroxide and sodium hydroxide without hydrofluoric acid or fluoride were used to strip the oxide films. The morphologies of the surface and cross-section of the oxide films before and after the films stripping were characterized by using scanning electron microscopy (SEM). The microstructure and chemical compositions of the oxide films before and after the films stripping were investigated by using Raman spectroscopy (Raman) and X-ray photoelectron spectroscopy (XPS). It was shown that the thickness of the oxide film was in the range of 5–6 μm. The oxide films were stripped for 2 to 8 min in the solution. Moreover, the effect of the stripping time on the efficiency of the film stripping was investigated, and the optimum stripping time was between 6–8 min. When the stripping solution completely dissolved the whole film, the α/β microstructure of the titanium alloy Ti-10V-2Fe-3Al was partly revealed. The stripping mechanism was discussed in terms of the dissolution of film delamination. The hydrogen peroxide had a significant effect on the dissolution of the titanium alloy anodic oxide film. The feasibility of the dissolution reaction also was evaluated.

A novel kind of waterborne epoxy coating pigmented by nano-sized aluminium powders on high strength steel was formulated. Several coatings with different pigment volume content (PVC) were prepared. The coating morphology was observed using scanning electron microscopy (SEM), and the electrochemical properties were investigated by electrochemical impedance spectroscopy (EIS). Immersion test and neutral salt spray test were also conducted to investigate the corrosion resistance of the coating. It is demonstrated that the critical pigment volume content (CPVC) value is between 30% and 40%. The coating with PVC of 30% exhibits good corrosion resistance in 3.5% (mass fraction) NaCl solution.

Ag nanoparticles have been synthesized successfully by using plasmid DNA as templates based on photoinduced method at room temperature. The plasmid DNA with an average size of 3980 base pairs was separated from Bacillus by using molecular biology methods. The morphology and composition of the samples were characterized by Transmission electron microscopy (TEM) and Energy dispersive spectroscopy (EDS). The UV–vis spectrum was applied to study the different stages of the synthesis processes. The results showed that the Ag was successfully deposited on the surface of plasmid DNA and formed the Ag nanoparticles with average sizes of ~ 30 nm. It was suggested that this high efficiency approach has promising application for the synthesis of other metal or alloy nanoparticles.

Hollow glass microspheres–CoFe2O4 (HGMs-CF) core-shell particles were successfully synthesized directly by using the homogeneous coprecipitation method at 90 °C without calcination. The morphology, composition, microstructure and the magnetic property of the samples were characterized by SEM, XRD, EDX and VSM, respectively. The results showed that the HGMs-CF core-shell particles exhibited smooth, compact and continuous CoFe2O4 coating on the surface of the HGMs. The Fe/Co atom ratio of the CoFe2O4 coating was 2.2, saturation magnetization (Ms) and coercivity (Hc) of the samples were 46 emu/g and 612 Oe, respectively. It was suggested that this method could be applied to the scale industry production for high purity products.

Anodic oxide films of titanium alloy Ti-10V-2Fe-3Al were sealed in calcium acetate solution. The morphology and composition of the sealed films were investigated using scanning electron microscopy (SEM), atomic force microscope (AFM) and energy dispersive spectroscopy (EDS). The results show that the sealing process makes the anodic oxide films more uniform. Elemental calcium is presented through the whole depth of the anodic oxide films. The roughness of the anodic oxide films is reduced after the sealing process. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization were used to study the corrosion behavior of the anodic oxide films. It is revealed that the sealing process improves the corrosion resistance of the anodic oxide film of titanium alloy Ti-10V-2Fe-3Al.

Porous anodic oxide films were fabricated galvanostatically on titanium alloy Ti-10V-2Fe-3Al in ammonium tartrate solution with different anodizing time. Scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM) were used to investigate the morphology evolution of the anodic oxide film. It is shown that above the breakdown voltage, oxygen is generated with the occurrence of drums morphology. These drums grow and extrude, which yields the compression stress. Subsequently, microcracks are generated. With continuous anodizing, porous oxides form at the microcracks. Those oxides grow and connect to each other, finally replace the microcrack morphology. The depth profile of the anodic oxide film formed at 1 800 s was examined by Auger electron spectroscopy (AES). It is found that the film is divided into three layers according to the molar fractions of elements. The outer layer is incorporated by carbon, which may come from electrolyte solution. The thickness of the outer layer is approximately 0.2–0.3 μm. The molar fractions of elements in the intermediate layer are extraordinarily stable, while those in the inner layer vary significantly with sputtering depth. The thicknesses of the intermediate layer and the inner layer are 2 μm and 1.0–1.5 μm, respectively. Moreover, the growth mechanism of porous anodic oxide films in neutral tartrate solution was proposed.

The effect of pre-corrosion on fatigue behavior of high strength steel 38CrMoAl was investigated with a fatigue test method using the accelerated pre-corrosion specimen in the neutral salt spray environment. The methods of weight-loss and energy dispersive spectrum (EDS) were adopted. The corrosion weight-loss rate was fitted with the test time using power law, and the relationship between the corrosion weightloss rate and the time was formulated. Moreover, the fatigue behaviors of the steel for different pre-corrosion time were investigated by the axis-direction tensile fatigue test. The fatigue life distribution characteristics of the pre-corrosion specimens were studied using the statistical probability methods, and the mathematical expectations and the standard tolerances of the material fatigue lives after different pre-corrosion time were obtained. It was found that the crack initiation of the high strength steel was accelerated by the preferential corrosion at the local plastic deform areas. The fatigue life obeys the lognormal distribution perfectly. Furthermore, within the common time range of the engineering, the standard tolerances of the logarithm of the fatigue life were independent of the pre-corrosion time.

The electrochemical behaviours of titanium alloy Ti-10V-2Fe-3Al after electropolishing in a self-developed electrolyte in comparison with conventional grinding were studied by electrochemical impedance spectroscopy (EIS). Optical microscopy (OM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to evaluate the surface characteristics of the alloy. It was found from the EIS experiments that the polarization resistance (Rp) was increased, the double layer capacitance (Qc) was decreased and the electrochemical impedance of the alloy was enhanced by electropolishing. The electropolished surface was flat, smooth and bright and its roughness was 3.310 nm. To underline the advantage of electropolishing process against grinding to provide the anodic oxidation process with a higher quality substrate, the ground and electropolished titanium alloys were anodized in parallel under the same conditions. The corrosion behaviours of the two kinds of anodized titanium alloys were compared. It was revealed that electropolishing generated a high quality substrate and improved the corrosion resistance of anodic oxide film formed on titanium alloy Ti-10V-2Fe-3Al. Furthermore, the mechanism of electropolishing improving the corrosion resistance of the anodic oxide film was proposed.

Anodic oxide films were fabricated on titanium alloy Ti-10V–2Fe–3Al in ammonium tartrate solutions at the concentrations: 1, 3, 5, 10 and 15 g L−1. The morphological characteristics and microstructures of the films of the alloy were studied by optical microscopy (OM) and Raman spectroscopy (Raman), respectively. The electrochemical impedances of the films in 0.5 mol L−1 H2SO4 solution were investigated by electrochemical impedance spectroscopy (EIS). It was showed that different electrolyte concentrations led to different change rates of anodizing forming voltage. The change rate significantly affected the morphology, microstructure and electrochemical impedance of anodic oxide film. When electrolyte concentration was 5 g L−1, anodic oxide film was the most uniform, exhibited by the least and smallest breakpoints on the film. In addition, the amount of crystal phase of the film was the largest at 5 g L−1, showed by the highest intensity of Raman peaks. Furthermore, the electrochemical impedance of the film of the alloy was the greatest at 5 g L−1, demonstrated by the highest values of polarization resistances and lowest values of capacitances. These phenomenon were associated with the minimum value of the change rate of anodizing forming voltage at 5 g L−1.

A new type of Ni metal material was prepared by bioforming machining technology based on the rod shape of Nocadia, one kind of bacteria. The material was studied by microbiological method, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and vibrant sample magnetometer (VSM) technology. It was found that the amount of Ni crystalline increased with processing time. The Nocadia maintained the original rod shape after Ni deposition. The thickness of Ni coating was about 100 nm. The volume of cytoplasm remained 5%–10% for the high temperature during the processing. The material prepared could be considered hollow compared with the original Nocadia. The new type Ni hollow material with nano-grains was prepared. The material exhibited a ferromagnetic behavior with saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) values of 46.67 emu/g, 18.43 emu/g and 230.9 Oe, respectively. Compared with those of the bulk Ni, Ms was decreased a little while Hc was enhanced greatly.

A new type Ni-P hollow material with rod-shape is prepared by electroless deposition method and heat treatment based on the shape of Nocadia, a kind of bacteria. The material is characterized and its magnetic, electromagnetic and mechanical properties are measured. It is found that the Ni-P coating transforms from a disordered structure before hollowing to an ordered arrangement of face centered cubic (FCC) Ni after hollowing at 673 K and body centered tetragonal Ni3P occurs. After hollowing no change of the surface morphology has been found. But the cytoplasm disappears and the Ni-P layer becomes more compact. A new type hollow material with shell thickness of 150–200 nm is obtained. The saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) are enhanced to 20 emu/g, 2.7 emu/g and 117.5 Oe, respectively. The dielectric and magnetic loss are improved to 14 and 0.4, respectively. The hardness and the elastic modulus are raised to 1.80 GPa and 23.79 GPa, respectively. All show great improvement compared with those before hollowing.

The surface of hollow glass spheres was deposited with a layer of Fe3O4 film in the open air without using ultrasound and toxic reducing reagent NaNO2; the magnetic films of Fe3O4 were characterized by XRD, SEM and EDS. The intactness of the films was remarkably affected by temperature; it is favorable for the hollow glass spheres to be encapsulated completely by the Fe3O4 magnetic films as plating temperature increased at pH 6.7. The films exhibited ferromagnetic behavior.

•ZnAlCe-LDHs were synthesized in the presence of different concentrations of Ce.•Ce (III) was successfully inserted into the sheets of LDH.•Two phases were formed when Ce/(Al + Ce) atomic ratio was higher than 0.05.•ZnAlCe-LDH nanoparticles were embedded into sol–gel film on aluminum alloy.•The anticorrosion property of coating system was enhanced after embedding LDHs.A protective coating was designed by dispersing Ce-doped ZnAl layered double hydroxides (ZnAlCe-LDHs) nanoparticles in hybrid sol–gel (SiOx/ZrOx) layer on aluminum alloy AA2024. The concentration of cerium in synthesized LDHs was varied to ascertain the optimum condition for anticorrosion performance. The LDH nanoparticles were characterized in terms of structure, morphology and chemical composition. It was found that Ce (III) was inserted into the sheets of LDHs and two mixture phases of LDHs and CeO2 were formed when the atomic ratio of Ce/(Al + Ce) was higher than 0.05. The sol–gel coating embedded with LDHs (Ce/(Al + Ce) = 0.1) exhibited high corrosion resistance, probably due to the synergistic inhibition of ZnAlCe-LDHs and CeO2 nanoparticles.

The performances of photovoltaic devices can be improved by using high electron mobility nanocomposites to increase charge collection and transportation. Single-walled carbon nanotubes (SWNTs) exhibit high electron mobility and are believed to be promising materials to enhance the power conversion efficiency of photovoltaic devices. Herein, we present DNA applied as a biological scaffold to fabricate SWNTs/TiO2 and SWNTs/TiO2/Ag nanocomposites, which are integrated into photoanode films to achieve high efficiency dye-sensitized solar cells (DSSCs). The effects of the amounts of SWNTs and Ag NPs in photoanode films on the performances of DSSCs are investigated. After incorporating the nanocomposites into photoanode films, the power conversion efficiency is enhanced. In particular, when the amounts of SWNTs and Ag NPs in the photoanode are 0.15 wt% and 0.8 wt%, the DSSC exhibits a high power conversion efficiency of ∼5.99%, ∼37.07% improvement compared with conventional TiO2-only DSSCs. The mechanisms of the performance improvement are discussed in detail.

Pd nanoparticles were introduced to individual Bacillus cells and dispersedly anchored on both the inside and outside of the cell walls. The anchored nanoparticles served as “seeds” to drive the formation of double metallic layers forming a metal–cell wall–metal sandwich structure at the single-cell level.