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The heat generation in the corrosion solution was precisely controlled and successfully induced the hydrolysis of (NH2)2CS, and an alkaline environment was created for the rapid growth of Ni(Fe)OOH/Ni(Fe)Sx.

Since there are not many studies on the application of polymeric surfactants in viscosity reduction emulsification of heavy oil, a series of polyether carboxylic acid–sulfonate polymeric surfactants were synthesized. The viscosity reduction performance and the effect of different chain lengths on the viscosity reduction effect were also investigated. The viscosity reduction, emulsification, wetting, and foaming performance tests showed that the viscosity reduction performance of this series of polymeric surfactants was excellent, with the viscosity reduction rate exceeding 95%, and the viscosity was reduced to 97 mPa·s by the polymeric surfactant with a molecular weight of 600 polyethers. It was also concluded that among the three surfactants with different side chains, the polymeric surfactant with a polyether molecular weight of 600, which is the medium side-chain length, had the best viscosity reduction performance. The study showed that the polyether carboxylic acid–sulfonate polymer surfactant had a promising application in the viscosity reduction of heavy oil.

Defects caused by the structural disorder of perovskites and voltage loss resulting from mismatched band structure are important issues to address to improve the performance of carbon-based perovskite solar cells. Different from the conventional approaches of additive-based passivation of perovskite precursors and introducing a hole-transport layer between the perovskite layer and carbon electrode, herein we report a defect-healing method using phenethyl ammonium iodide (PEAI) treatment and band-structure modification using high-work-function inorganic copper phthalocyanine (CuPc). Because of its relatively smoother surfaces and lower defect content, the optimized device after PEAI-based passivation of the perovskite achieves a power conversion efficiency (PCE) of 11.74%. The PCE is further raised to 13.41% through the auxiliary energy-level matching and high hole extraction abilities of the CuPc-modified carbon electrode. The best-performing device exhibits excellent moisture tolerance and thermal stability with minor current density–voltage hysteresis.

A low-temperature carbon electrode with good perovskite compatibility is employed in hole-transport-material free perovskite solar cells, and a champion power conversion efficiency (PCE) of 11.7% is obtained. The PCE is enhanced to 14.55% by an interface modification of PEDOT:PSS. The application of this carbon on ITO/PEN substrates is also demonstrated.

It is a highly desirable but still a challenging task to find a simple, fast and straightforward method to greatly improve the electrochemical properties of a Co3O4 electrode for pseudocapacitors. In this study, we demonstrate that developing an amorphous Co–phosphate (Co–Pi) shell via in situ surface derivatization on a Co3O4 nanowire (NW) surface facilitates the diffusion and reaction of electrolyte ions and leads to distinctive conductivity. Because of these advantages, 1D nanostructures and the synergistic effect between Co3O4 and amorphous Co–Pi, the resulting core–shell Co3O4@Co–Pi nanowire (NW) array exhibits high capacitance (1692 F g−1 at current density of 1 A g−1). In addition, high rate capabilities and retention capacity of 86% after 6000 cycles at 20 A g−1 are achieved. By using the Co3O4@Co–Pi core–shell hybrid NW array and activated carbon as the anode and cathode, respectively, asymmetric pseudocapacitors are assembled that exhibit high capacitance (energy density of 35.69 W h kg−1 at power density of 558 W kg−1) and super-long cycle life (82% capacitance retention after 40 000 cycles). Our synthesis method provides a new technology for the design of composites of transition metal oxides/hydroxides and phosphates for electrochemical energy storage applications.

This review gives an overview of the synthetic strategies used for designing metal-organic frameworks (MOFs) and MOFs-based composites studied for water-alcohol separation applications. It shows that various organic linkers, including flexible, hydrophobic and zwitterionic ligands have been used for the synthesis of MOFs with flexible frameworks, highly hydrophobic MOFs as well as MOFs with unique electronic distribution in the pores. Due to their specific structural properties, all these materials show different adsorption behavior in the presence of water and alcohols, being able to separate water-alcohol mixtures. Several studies focused on using microporous MOFs to separate water-alcohol mixtures based on the difference in the molecular size of water and alcohols. Combining MOFs with organic polymers into composites is viewed as a viable alternative to tackle some problems that powdered MOFs may cause in industrial applications. The research so far shows that MOFs embedded in polymer matrixes have led to improved efficiency and mixture permeability when comparing with the performance of pristine polymer membranes. Nevertheless, the design of membranes with high permeability, selectivity and stability is difficult due to the swelling of the polymer matrix as well as the difficulties in retaining the matrix integrity while increasing the MOF loading.

In this work, we report on the use of hydrothermal and hydrogenation processes to synthesize oxygen-deficient NiMoO4 nanoflake arrays (OD-NF) and nanowire arrays (OD-NW) for electrode applications. The introduction of oxygen vacancies into NiMoO4 increased the interlayer spacing of the crystal structure and Mo6+ in NiMoO4 was partially reduced to Mo4+. In addition to increasing the conductivity, the oxygen vacancies also promoted charge storage kinetics, while retaining the crystal structure of NiMoO4. The oxygen vacancies considerably influenced the capacitive performance of NiMoO4. Notably, OD-NF showed better electrochemical performance than that of OD-NW. Furthermore, our asymmetric supercapacitor device composed of NiMoO4 OD-NF and active carbon achieved 49.1 Wh kg−1 at a power density of 800 W kg−1 and retained a remarkable 94.2% specific capacitance after 6000 cycles.

It remains a challenge to develop simple and mild strategies for synthesizing various Co(OH)2 nanostructures on substrates. Inspired by semipermeable membranes, a Celgard membrane was used as an interface for separating components of the precursor solution and for ion exchange, to construct hierarchical Co(OH)2 nanostructures. In contrast to traditional solvothermal reactions, this Celgard membrane-based method is simple and effective for preparing high-loading Co(OH)2 array (density of approximately 7 mg cm−2) on Ni foam. The permeability of the Celgard membrane was affected by the presence of an organic solvent. The morphology of Co(OH)2 could be adjusted by controlling the OH− diffusion rate across the Celgard membrane. OH− was formed via the hydrolysis of urea solution. The optimized Co(OH)2 nanosheet electrode exhibited a specific capacitance of 2406 F g−1 at 1 A g−1, and good cycling stability (89.1% capacitance retention after 5000 cycles) in 2 M aqueous KOH aqueous solution, using a typical three-electrode cell. An asymmetric supercapacitor was assembled with a Co(OH)2 nanosheet array as the positive electrode, and activated carbon as the negative electrode. The asymmetric supercapacitor exhibited a high energy density (39.2 W h kg−1), high power density (9.2 kW kg−1 at 28.9 W h kg−1), and excellent cycling stability (84.2% capacitance retention after 10,000 cycles).

β-Ni(OH)2 is considered a potential candidate of supercapacitor electrode material due to its high theoretical capacitance and cost efficiency. In order for β-Ni(OH)2 electrode to achieve high areal capacitances, we report effective fabrication of high mass loading low-crystalline β-Ni(OH)2 on nickel foam through the acid-etching formation of Ni3(PO4)2 precursor and the subsequent electrochemical activation. The heavily-loaded (13.5 mg cm−2), binder-free β-Ni(OH)2 electrode presents a high areal capacitance of 15.31F cm−2 (1134F g−1) at current density of 30 mA cm−2 (2.22 A g−1) and has a capacitance retention of 85% after 10,000 cycles at a high current density of 110 mA cm−2 (7.41 A g−1). Besides, the assembled hybrid supercapacitors can deliver an areal capacitance of 2.59F cm−2 at 20 mA cm−2 with a maximum energy density of 0.49 mWh cm−2 (2.45 mWh cm−3). This work provides a certain reference for exploring a low-cost and large-scale method of material synthesis at room temperature for high mass loading and capacitance in the future application.

Herein, gas bubbles generated in situ from precursors assist the rapid construction of hollow sycamore fruit-like CoMoO4 spheres (HSCSs). This bubble-assisted fabrication strategy is easy to operate, ultra-fast, low cost and post-treatment-free, showing great potential for the large-scale production of HSCSs. The growth mechanism of HSCSs is discussed to reveal the evolution process, which may be generalized to the construction of a series of hollow ternary Mo-based oxides. The obtained HSCSs exhibit a superior specific capacitance and outstanding cyclic stability when applied in supercapacitors.

The design of artificial photosynthetic systems (APSs) with hierarchical porosity by taking into account liquid flow and gas transport effects is of high significance. Herein we demonstrate a general and facile strategy to prepare hierarchical 1D to 3D macro/meso/nanoscopic morph-tunable g-C3N4 assemblies via bio-directed morphology engineering for enhanced artificial photosynthesis of CO and methane via CO2 reduction. Escherichia coli (1D), Papilio nephelus wings (2D, planar) and cole pollen (3D) are adopted for 1D to 3D multiscale assemblies with high surface areas via a two-step transformation process. Moreover, liquid flow and gas diffusion behaviors are investigated using COMSOL computational simulation to reveal the relationship between structural effects and output efficiency theoretically. Such methodology can be extended to realize versatile fabrication of various morph-tunable carbon nitride assemblies. Importantly, this research illustrates the power of combining theoretical calculations and experimental techniques to achieve the controlled design of high efficiency APS and may provide further avenues to APS optimization.

Interstitial (Li) and substitutional-type (Mo) co-doped new-type urchin-like Lix(Mo0.3V0.7)2O5 (LMVO) is fabricated via in situ gas bubble template strategy, which leads to distinctive conductivity, high number of active sites, reversible ion intercalation and accessible redox couple. Consequently, the electrochemical performance of LMVO is enhanced enormously owing to the hollow morphology and unique electronic structure. The charge storage capability of the synthetic LMVO is investigated in Mg2+ and Zn2+ electrolytes as well as Li+ electrolyte, due to the similar radius, higher charge, abundant reserve and rational cost. As a result, LMVO achieves a specific capacitance of 484 F g−1 at 1 A g−1 in Zn2+ electrolyte, which apparently surpasses the performance in Li+ and Mg2+ electrolytes. Moreover, the assembled LMVO//LMVO device delivers a specific capacitance of 117 F g−1 at 0.8 A g−1, which indicates large potential for application.

The state-of-the-art perovskite solar cells (PSCs) with SnO2 electron transporting material (ETL) layer displays the probability of conquering the low electron mobility and serious leakage current loss of the TiO2 ETL layer in photoelectronic devices. The rapid development of SnO2 ETL layer has brought perovskite efficiencies >20%. However, high density of defect states and voltage loss of high temperature SnO2 are still latent impediment for the long-term stability and hysteresis effect of photovoltaics. Herein, Nb5+ doped SnO2 with deeper energy level is utilized as a compact ETL for printable mesoscopic PSCs. It promotes carrier concentration increase caused by n-type doping, assists Fermi energy level and conduction band minimum to move the deeper energy level, and significantly reduces interface carrier recombination, thus increasing the photovoltage of the device. As a result, the use of Nb5+ doped SnO2 brings high photovoltage of 0.92 V, which is 40 mV higher than that of 0.88 V for device based on SnO2 compact layer. The resulting PSCs displays outstanding efficiency of 13.53%, which contains an ∼10% improvements compared to those without Nb5+ doping. Our study emphasizes the significance of element doping for compact layer and lays the groundwork for high efficiency PSCs.

A facile hydrothermal method is developed for fabrication of large-scale NiMoO4·H2O arrays with robust adhesion on Ni foam. Importantly, the morphology of NiMoO4·H2O can be easily controlled to be nanoflake (H-NF) or nanowire (H-NW) arrays by using NH4F as additive. The obtained nanoflake morphology delivers better electrochemical activity than that of nanowire. The electrochemical performance of anhydrous NiMoO4 arrays obtained by annealing the NiMoO4·H2O has also been investigated for comparison. It is believed that the presence of the structural water of NiMoO4 enhances the capacitive performance by making it a good ionic conductor. Furthermore, an asymmetric supercapacitor (ASC) is constructed using the as-prepared NiMoO4·H2O nanoflake arrays as the positive electrode and activated carbon (AC) as the negative electrode. The optimized ASC with an extended operating voltage range of 0–1.6 V displays excellent electrochemical performance with a high energy density of 53.8 W h kg−1 at a power density of 239 W kg−1 in addition to superior rate capability. Moreover, the H-NF//AC ASC device exhibits remarkable cycling stability with 73.4% specific capacitance retention after 4000 cycles. Our result shows that this unique NiMoO4·H2O nanoflake array is promising for electrochemical energy applications.

Zn 3 (OH) 2 V 2 O 7 ·2H 2 O samples with high visible-light photocatalytic water oxidation activity were hydrothermally fabricated at different pH conditions. The crystalline phase, morphology and local crystal structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transition electron microscopy (TEM), corresponding selected area diffraction (SAED) and Raman techniques. According to the SEM results, all the samples exhibited aggregates of irregular nanoplates with the average diameter of 100–200 nm and thickness of ∼20 nm. Furthermore, some factors, such as pH conditions, influencing the morphologies and local crystal structure of the Zn 3 (OH) 2 V 2 O 7 ·2H 2 O nanoplates have been systematically investigated. The photocatalytic activities of the Zn 3 (OH) 2 V 2 O 7 ·2H 2 O were evaluated by photocatalytic water oxidation under visible light irradiation. It was found that Zn 3 (OH) 2 V 2 O 7 ·2H 2 O prepared at low pH exhibited high photocatalytic water oxidation activity, indicating that different morphologies and the different extent of local crystal structure distortion can effectively influence the water oxidation activity of Zn 3 (OH) 2 V 2 O 7 ·2H 2 O. Moreover, the relationship between the exposed facets of Zn 3 (OH) 2 V 2 O 7 ·2H 2 O and the H 2 O molecule adsorption was investigated by density functional theory (DFT). The results of our study indicated that the extent of connection between polyhedrons on exposed facet of the Zn 3 (OH) 2 V 2 O 7 ·2H 2 O can significantly affect the sample's H 2 O molecule adsorption activity.

We developed a facile method for the synthesis of visible light responsive ZnO through the introduction of different concentrations of oxygen vacancy for efficient formaldehyde photodegradation under visible light irradiation. The visible light active ZnO was prepared using ZnO 2 instead of traditional Zn(OH) 2 as a precursor. According to the results of Raman and XPS, the concentrations of oxygen vacancy decreased with the increase of annealing temperatures. The effects of different concentrations of oxygen vacancy on the electronic structure of ZnO were investigated by density functional theory (DFT) simulation and the results were confirmed by UV–VIS spectra, which showed the oxygen vacancy narrowed the band gap of ZnO. ZnO with stable concentration of oxygen vacancy was used for formaldehyde photodegradation. The results of photocatalytic experiments reflected that oxygen vacancy can not only act as impurity levels in the band structure of ZnO but can also work as electron traps to accept the photogenerated electrons. The oxygen vacancy in ZnO effectively prohibited the recombination of electron–hole pairs, enhancing the photocatalytic activity of ZnO. The results of our study provide us useful information for the understanding of the mechanisms of the photocatalytic process of ZnO with oxygen vacancy.

Novel ZnO/SnO 2 core–shell nanoneedle arrays were developed with a two-step synthesis strategy. The strategy combines two processes: a hydrothermal synthesis of a ZnO nanoneedle array and a coating of a SnO 2 layer on the surface of the ZnO nanoneedle. The addition of F − to the hydrothermal reaction solution played an important role in the formation of the ZnO nanoneedle array. The ZnO/SnO 2 core–shell structure was successfully achieved after depositing a thin SnO 2 layer on the ZnO nanoneedle by dip-coating. Dye-sensitized solar cells (DSSCs) based on ZnO/SnO 2 core–shell nanoneedle arrays were assembled, and a high conversion efficiency ( η ) of around 4.71% was obtained at 0.9 suns. This can be attributed to the advantages of the core–shell structure. On the one hand, it affords a larger surface area for a more dye loading and light harvesting, which result in enhancing the photocurrent of the DSSC. On the other hand, the core/shell structure passivates nanoneedle surface defects for suppressing the recombination, which leads to the increase of the open-circuit voltage. Accordingly, the enhanced photocurrent and open-circuit voltage have led to a prominent increase in the photovoltaic efficiency of around 4.71%, which is much higher than that of an ordinary ZnO nanoneedle array-based DSSC.

Diverse biological microstructures that result in advanced optical effects have been systematically investigated. However, the mechanisms of polarization-sensitive color have not been fully understood. Here, we report a combined architecture comprising upper deep grating and bottom multilayer in butterfly iridescent scales that leads to polarization-sensitive color related with scale azimuth. The polarization process is unraveled through detailed investigations on the green scales in butterfly Ornithoptera priamus poseidon and the orange scales in butterfly Ornithoptera croesus lydius. The bright green and orange scales result from the interaction between the transmitted 0th order diffraction of upper grating and the 1st order interference of the bottom multilayer. Combining experimental results with calculation, we clarify the structural origin and the mechanism of the polarization conversion. Tapered grating achieves form-birefringence rotating polarized light and the multilayer selectively reflects the incident light dominating the reflection color. The height of the grating, which determines the phase difference of the two decomposed polarized lights, is essential to polarization conversion. To our knowledge, it is the first study to provide a structural prototype comprising deep grating and multilayer for achieving polarization-sensitive color. These findings show significant promise in biosensing, anticounterfeiting and optical-material design.

In this work, we report the synthesis of hybrid nanowire arrays by growing highly conductive carbon onto rough CoO nanowire arrays on 3D nickel foam. The CoO@C nanostructure arrays (CCNAs) are obtained via a hydrothermal method, followed by controlling the annealing and carbon deposition process at a relatively low temperature in the chemical vapor deposition (CVD) stage. In the carbon shell, apart from partial amorphous carbon, crystalline carbon was observed via TEM. With deposited carbon, the electrical conductivity and capacitance behaviors are dramatically promoted. The growth mechanism is proposed by TEM and XPS analyses, which firstly indicates that CoO could catalyze the decomposition of C2H2 at the low temperature of 427 °C in a reduction and catalytic process. The obtained CCNAs with a more hydrophilic surface and low resistance are tested as the working electrodes of supercapacitors, which lead to an ultrahigh specific capacitance of 3282.2 F g−1 approaching to the theoretical value. Good rate capability and 96.9% capacitance retention after 10 000 cycles suggest that such hybrid electrode possesses a great potential application. After assembling it as the positive electrode and activated carbon as the negative electrode, the aqueous asymmetric supercapacitor demonstrates an energy density value up to ∼58.9 W h kg−1 which is the highest value achieved among the Co-based supercapacitors.

A novel carbon-CoO-NiO-NiCo2O4 integrated electrode has been designed by reducing the hetero-structured NiCo2O4 nanosheet array with C2H2 on the nickel foam at a low temperature of 350 °C. The topotactical transformation from NiCo2O4 to the integrated electrode has been first conceived and investigated. Such unique nanoarchitectures exhibit excellent electrochemical performance with ultrahigh capacitance and desirable cycle life at high rates.

Zn-doped Cu2O polyhedrons with various crystal morphologies, from 50-facet and 26-facet to 8-facet, were synthesized via a mild, low-temperature process based on the hydrothermal method. Addition of zinc salt to the reaction mixture might allow the introduction of Zn ions into the Cu2O crystal lattice, which is shown by X-ray photoelectron spectroscopy and energy dispersive spectroscopy. Doping of Cu2O crystals with Zn affects not only their morphologies but also significantly influences their optoelectronic properties. UV–visible and photoluminescence (PL) tests showed that the Zn-doped Cu2O system displays an increased band gap and enhanced photoluminescence properties. The open circuit potential-time (Ocp-t) method shows that a pure Cu2O crystal is an n-type semiconductor, while the Zn-doped Cu2O crystal shows p-type characteristics.

In this paper, we design a strategy to obtain core–shell carbon-coated CaSnO3 nanotubes (hereafter C-CTO NTs) directly via a facile subsequent solvothermal synthesis using CaSn(OH)6 nanotubes as precursor in a mixed ethanol and water solvent. The mixed solvent not only facilitates the phase transformation of CaSnO3 from CaSn(OH)6 to take place quickly, but also retains the tube-shaped morphology. The uniform decoration of C shell on the surface of CaSnO3 nanotubes (hereafter CTO NTs) was confirmed by EELS (electron energy loss spectroscopy). Moreover we found that the uniform carbon-coating layer on the surface of CTO NTs played roles of a good conductor and a structure buffer to alleviate the strains from the volume variation of CTO NTs cores. So the core–shell structure possesses both the electroactivity of C and the advantages of nanotube structure. When used as an anode for Li ion battery, it shows enhanced cycling performance in term of cycling stability over bare CTO NT electrode and CaSnO3 nanocube (hereafter CTO NC) electrode. To our best knowledge, this is the first attempt to use C-CTO NTs as an anode in Li ion battery.

In the present work, high surface area mesoporous cobalt oxide (Co 3 O 4 ) nanobelts have been synthesized by thermal treatment of cobalt hydroxide carbonate (CHC) precursors. CHC nanobelts were prepared by a facile hydrothermal method. Control experiments with variations in reaction time, solvent and different cobalt source revealed that temperature and sulfates are key factors in determining the formation of CHC nanobelts. Scanning electron microscopy and transmission electron microscopy images showed that the Co 3 O 4 nanobelts consisted of mesoporous nanobelts with the average width of 40 nm. Brunauer–Emmett–Teller (BET) gas adsorption measurement further indicated that the products presented a rather large surface area (172.09 m 2 g −1 ).

We present a strategy to synthesize porous BaSnO 3 hollow architectures with that were 150–300 nm in diameter and 1.5–5 μm in length using precursor of BaCO 3 @SnO 2 nanorods prepared by hydrothermal treatment. BaCO 3 @SnO 2 nanorods, consisting of a BaCO 3 core and a SnO 2 shell, could be used effectively for the solid-state synthesis of polycrystalline BaSnO 3 powder at 800 °C (lower than convention for BaCO 3 and SnO 2 mixtures). The core/shell structure of the precursor could play a role as a structural directing template for preparing BaSnO 3 hollow architectures during the calcination process. The X-ray diffractometer (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) are employed to characterize the structures and morphologies. When applied to DSSC, the porous BaSnO 3 hollow architectures exhibit distinct photovoltaic effect.

Low-dimensional single-crystalline CdCO3 nanostructures such as nanowires, nanobelts, nanorolls, and one-dimensional (1D) hierarchical structures have been synthesized through a convenient, low-temperature hydrothermal method, and the products have been characterized by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and selected area electronic diffraction. The influences of ammonia concentration, reaction time, and temperature on the morphologies of CdCO3 have been investigated. In addition, these low-dimensional nanostructures can be transformed into oriented CdO nanoporous structures through heat treatment processing, and the corresponding shapes can be preserved completely.

The adsorption of nicotine and tar from the mainstream smoke (MS) by the filter tips filled respectively with oxidized carbon nanotubes (O-CNTs), activated carbon and zeolite (NaY) has been investigated. O-CNTs show exceptional removal efficiency and their adsorption mechanism is investigated. Capillary condensation of some ingredients from MS in the inner hole of O-CNTs is observed and may be the primary reason for their superior removal efficiency. The effect of O-CNTs mass on the removal efficiencies is also studied and the results show that about 20–30 mg O-CNTs per cigarette can effectively remove most of nicotine and tar.

The electron irradiation effect on 80/20 poly(vinylidene fluoride–trifluoroethylene) [P(VDF–TrFE)] copolymers was studied by FTIR spectra and X-ray diffraction. Infrared spectra showed decreasing intensity of bands at 1430, 1286, 846, and 505 cm−1, the appearance and intensity increasing with irradiation doses of bands at 768, 601, and 1735 cm−1, which revealed the conformational change after irradiation. The X-ray diffraction patterns exhibited a decrease of volume fraction of ferroelectric phase and expansion of the lattice space. The electron-irradiated P(VDF–TrFE) films showed structural changes and polar phase to nonpolar phase transformation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2903–2907, 2004

The Au nanoparticle sandwich double spheric-shells of SiO2@Au@TiO2 (SAT) microspheres are synthesized. The significant influence of the SAT microspheres on the properties of dye-sensitized solar cells (DSSCs) is investigated. Studies indicate that the introduction of SAT markedly enhanced the light scattering and capture ability of DSSCs and thus photogenerated electrons. DSSCs doped with 2.25 wt% SAT exhibit a maximum short circuit current density of 17.0 mA cm-2 and photoelectric conversion efficiency of 7.14%, which are remarkably higher than those of conventional DSSCs at 15.7% and 21.2%, respectively. The marked enhancement in the performance of the optimal DSSCs can be attributed to the synergetic complementary effect of the enhanced light scattering of the microspheres and to the localized surface plasmon resonance of the Au nanoparticles in the SAT, and is a novel promising way of enhancing the performance of DSSCs.

A high-performance supercapacitor electrode is designed and fabricated with the 3D interconnected continuous nanoporous Co/CoO core-shell hybrid nanostructure grown on nickel foam. The Co/CoO core-shell hybrid nanostructures are obtained via a hydrothermal method, followed by high-temperature annealing in hydrogen atmosphere, and finally placed in air at 50 °C for 1 h. The Co/CoO core-shell nanostructure assembled by a conductive metal-core and a CoO shell, brings low resistance, high specific capacitance of 5.632 F cm-2 and good capability stability (81.5% capacitance retention after 6000 cycles). An asymmetric supercapacitor device built by the Co/CoO (positive electrode) and activated carbon (negative electrode) can deliver a working voltage of 1.7 V and display a high energy density of 0.002 67 Wh cm-2 at a power density of 0.001 62 W cm-2, which is far superior to that of a supercapacitor at a similar power density.

Nanobelts of nickel hydroxyl sulfate have been prepared on a large scale via a simple template-free hydrothermal reaction on the basis of a complex [Ni(NH(3))(6)](2+) formed with Ni(2+) and ammonia in an ethanol-water solution. The as-synthesized nanobelts were single crystals, with several tens of microns in length and 50-150 nm in width. The nanobelts were enclosed by top surfaces (100) and side surfaces (001) and their growth direction was parallel to [010]. The function of aqueous ammonia and ethanol was discussed. Furthermore, nanostructures of a mixture of crystralline NiO and amorphous nickel sulfate with various morphologies, such as nanobelts, porous nanobelts, and nanoparticles, were obtained by the thermal treatment of the as-synthesized Ni(SO(4))(0.3)(OH)(1.4) nanobelts at different temperatures.

In this paper we reported the preparation and characterization of the nanostrutured CdS/ZnO nanoarray thin film, based on the free-standing ZnO nanorod-array. The method was simple and low-cost. The ZnO nanorod-arrays were synthesized on F-doped tin oxide glass (TCO) substrate by hydrothermal method, then coated with CdS nanoparticles closely via chemical bath deposition method. The resulting thin films showed better photoelectrochemical performances than those of CdS/ZnO nanoparticles thin films. Under the illumination of AM 1.5 simulated sunlight (30 mW/cm2), the photocurrent of the samples achieved to 0.72 mA/cm2.

One-dimensional CuO nanoribbons and three-dimensional CuO nanoflowers were synthesized via a facile, rapid, low-temperature, one-pot water bath method, in which the synthesis was performed in Cu(CH3COO)2/NaOH and aqueous/ethanol systems at 70 °C for 15 min. Control over the shape and dimensionality of the well-defined CuO single crystals was achieved simply by varying the order of addition of the reactive materials. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction were used to characterize the products. The formation mechanism in the in situ, rapid reaction was investigated. In Brunauer-Emmett-Teller and thermogravimetry measurements, the nanoribbons exhibited a higher specific surface area and higher adsorption capabilities than the nanoflowers. Using cyclic voltammetry, chronopotentiometry and EIS measurement for supercapacitance, it was shown that the nanoflower electrodes had better performance than the nanoribbon electrodes, however, the nanoribbon/C electrodes had better performance than the nanoflower/C electrodes at lower current density, but were worse at higher current density.

This paper describes a facile solvothermal method to synthesize self-assembled three-dimensional (3D) Ni2+-Fe3+ layered double hydroxides (LDHs). Flower-like Ni2+-Fe3+ LDHs constructed of thin nanopetals were obtained using ethylene glycol (EG) as a chelating reagent and urea as a hydrolysis agent. The reaction mechanism and self-assembly process are discussed. After calcinating the as-prepared LDHs at 450 degrees C in nitrogen gas, porous NiO/NiFe2O4 nanosheets were obtained. This work resulted in the development of a simple, cheap, and effective route for the fabrication of large area Ni2+-Fe3+ LDHs as well as porous NiO/NiFe2O4 nanosheets.