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Novel feather-like CeO2 microstructures were achieved by a thermal decomposition approach of Ce(OH)CO3 precursor. The Ce(OH)CO3 was obtained from a solvothermal method employing Ce(NO3)3.6H2O with C6H[Formula: see text]N4 and C[Formula: see text]H[Formula: see text](CH3)3NBr (CTAB) at 190[Formula: see text]C in a water–PEG-200 mixed solution. The feather-like CeO2 dendrite was obtained by thermal conversion of the feather-like Ce(OH)CO3 at 650[Formula: see text]C in air. A reasonable growth mechanism was proposed with the soft-template effect of PEG-200. The electrochemical behavior and enzyme activity of myoglobin (Mb) immobilized on CeO2–Nafion modified glassy carbon electrode (GCE) are demonstrated by cyclic voltammetric measurements. The results indicate that CeO2 can obviously promote the direct electron transfer between the Mb redox centers and the electrode. The Mb on CeO2–Nafion behaves as an elegant performance on the electrochemical reduction of trichloroacetic acid (TCA) from 0.32[Formula: see text][Formula: see text]M to 2.28[Formula: see text][Formula: see text]M. The detection limit is estimated to be 0.08[Formula: see text][Formula: see text]M.

Novel anatase TiO2 hollow boxes and tree-like structures assembled by hollow tubes with a surface area as high as 241.89 m2/g can be synthesized in large scale by a simple hydrothermal method. A di...

A family of functional metal oxide nanotubes such as TiO2, Fe2O3, SnO2, ZrO2, and SnO2@Fe2O3 composite can be successfully fabricated by using highly active carbonaceous nanofibres as templates, which are synthesized via a hydrothermal approach. Compared with the previous strategy of using carbon nanotubes as templates, the carbonaceous nanofibres synthesized by the hydrothermal approach have higher reactivity, thus making them more suitable for templating synthesis of a variety of metal oxide nanotubes. This general method can be further developed to synthesize uniform ternary oxide nanotubes such as BaTiO3 and metal oxide composite nanotubes. The gas sensitivity of SnO2nanotubes synthesized by this approach has showed higher sensitivity, which exemplifies the distinct properties of such 1D hollow nanostructures. These uniform nanotubes might find potential applications in fields such as catalysis, chemical/biological separation, and sensing.

Using N,N′-dicyclohexylcarbodiimide (DCC) and l-serine as biologic additives, rutile TiO2 hollow spheres assembled by nanorods can be synthesized by a simple hydrothermal reaction route. A distinctive crystallization and transformation route of the rutile TiO2 hollow spheres has been proposed, which includes emergence of polycrystalline, mesoscale transformation to mesocrystals with morphologies of sectors, transformation of mesocrystals to bundles of rods based on oriented attachment, the simultaneous assembled process of sectors to solid spheres, and a cavitating process of solid spheres through the Ostwald ripening mechanism. Two ways of oriented attachment, side-by-side and end-to-end, were observed during the assembly process. It has been found that the presence of DCC and l-serine and their synergistic effects are essential for the formation of rutile TiO2 hollow spheres. The stability of the rutile TiO2 mesocrystals has been studied. The results have demonstrated that the mesocrystals could be main...

Three-dimensional (3D) urchin-like MnWO4 microspheres with a diameter of ca. 1−1.2 μm assembled by nanorods with a length of 240 nm and an aspect ratio of ca. 9 have been fabricated by a cationic surfactant cetyltrimethyl ammonium bromide (CTAB) assisted hydrothermal method. The result demonstrated that CTAB played an important role as a soft template in directing growth and self-assembly of urchin-like MnWO4 microspheres, and suitable pH values and reaction temperature are also essential for the formation of urchin-like microspheres. Magnetic measurement indicates that urchin-like MnWO4 microspheres show a weak ferromagnetic ordering at low temperature due to spin-canting and surface spins of microspheres, while much shorter MnWO4 nanorods show antiferromagnetism at low temperature.

Biocompatible and green luminescent monodisperse silver/phenol formaldehyde resin core/shell spheres with controllable sizes, in the range of 180 to 1000 nm, and interesting architectures (centric, eccentric, and coenocytic core/shell spheres) have been synthesized by a facile one-step hydrothermal approach. These spheres can be used as bioimaging labels for human lung cancer H1299 cells. The results demonstrate that the nanoparticles can be internalized into cells and exhibit no cytotoxic effects, showing that such novel biocompatible core/shell structures can potentially be used as in vivo bioimaging labels. This facile one-pot polymerization and encapsulation technique may provide a useful tool to synthesize other core/shell particles that have potential application in biotechnology.

Ultralong Cu@carbonaceous submicrocables with diameters of 0.4−0.6 μm and lengths up to and exceeding 100 μm have been fabricated successfully by a poly(vinyl alcohol)- (PVA-) assisted hydrothermal carbonization process using copper chloride and maltose as materials. In this one-pot synthesis, poly(vinyl alcohol) (PVA) played an important role in the formation of these submicrocables as a structure-directing agent to effectively restrain the formation of carbonaceous spheres that are normally nucleated from bulk solutions. In addition, the combined synergistic effects of both the carbohydrates and the PVA enable the formation of elegant Cu@carbonaceous submicrocables. Furthermore, control of the initial pH value (∼7−8) and reaction temperature (∼180 °C) is also essential for the formation of cablelike structures. The effects of other saccharides such as glucose, β-cyclodextrin, and starch on the formation of Cu@carbonaceous submicrocables were also examined under similar conditions. The thermal stability ...

An acetic acid-assisted solution reaction at 80 °C has been developed to synthesize complex CuS microtubes with a diameter about 800 nm and length up to 16 μm, which were constructed by hexagonal copper sulfide nanoflakes. The formation process of complex microtube-like structures suggested that one-dimensional microrods of the initial precursor [Cu−(TAA)2]Cl2 complex acted as sacrificial templates for the self-aggregation and oriented growth of CuS nanoflakes on their backbones.

Cross-linking reaction of poly(vinyl alcohol) (PVA) can be initiated in the presence of copper ions, resulting in the formation of copper@cross-linked PVA nanocables by a one-step hydrothermal approach. In contrast to our previous findings in the case of silver ions, metal ions with high valency are more difficult to reduce during the cross-linking reactions under hydrothermal conditions. The variation of pH value during the reaction has significant effects on the quality of the product. Copper@cross-linked PVA nanocables with a diameter of 0.5–1 µm and length up to 100 µm can be obtained at 200 °C, accompanying the presence of some cross-linked PVA aggregates with near spherical shape and irregular shape. The pH value, reaction temperature, and reaction time play key roles in the formation of such nanocables. The results demonstrated that the cross-linking reaction in the presence of different metal ions has different reaction rates, which determine the uniformity of the product and the quality of the cable-like core–shell structures.

Zinc oxide flowers composed of either branched spindles or prismatic whiskers with flat ends have been synthesized by hydrothermal treatment of Zn3(OH)2V2O7·H2O nanosheets in sodium hydroxide aqueous solution at 120 °C. The influence of basicity, temperature, and reaction time on the formation of such structures was investigated. The room-temperature photoluminescence spectrum of the ZnO branched structures shows strong green-yellow emission. The results indicated that the choice of a precursor with special shape could have significant influence on the growth of ZnO crystals. This precursor could be used for the synthesis of other zinc compounds with complex morphology and special nanostructures.

Bi2S3/SnS2 heterostructured photocatalysts were synthesized from BiOI, SnCl[Formula: see text]5H2O and NH2CSNH2 using an economic and simple hydrothermal method. The as-synthesized samples were characterized by X-ray diffraction, scanning electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy. The photodegradation activities of the Bi2S3/SnS2 heterostructured photocatalysts were estimated by degrading rhodamine B under simulated sunlight supplied by irradiating with a 350[Formula: see text]W Xe lamp. Bi2S3/SnS2 photocatalysts were prepared using varying percentages of Bi2S3. The sample containing 13% Bi2S3 had the most efficient photocatalyst performance among the tested samples. The photocatalytic mechanism involves heterojunctions formed in the Bi2S3/SnS2, which promoted effective separation of photoinduced electrons and holes.

Nanoporous VSB-5 nickel phosphate molecular sieves with relatively well controllable sizes and morphology of microspheres assembled from nanorods were synthesized at 140 degrees C over a short time in the presence of hexamethylenetetramine (HMT) by a facile hydrothermal method. The pH value, reaction time, and ratio of HMT to NaHPO2.H2O crucially influence the morphology and quality of the final products. By adjusting the pH value of the initial reaction solution, the morphology changes from disperse rods to microspheres assembled from rods and finally to a large quantity of fibers, and the diameters of the VSB-5 rods can be varied. The catalytic activity of VSB-5 in selective hydrogenation of several unsaturated organic compounds was tested. Nickel(II) in VSB-5 can selectively catalyze hydrogenation of C=C in trans-cinnamaldehyde and 3-methylcrotonaldehyde. In addition, since nitrobenzene (NB) and 2-chloronitrobenzene could be reduced to aniline (AN) and 2-chloroaniline with high selectivity, VSB-5 could have potential applications in synthesizing dyes, agrochemicals, and pharmaceuticals.

Large-scale selective synthesis of uniform single crystalline tellurium nanowires with a diameter of 4-9 nm, and microbelts with a width of 250-800 nm and tens of micrometers in length, can be realized by a poly (vinyl pyrrolidone) (PVP)-assisted hydrothermal process. The formation of tellurium nanowires and nanobelts in the presence of PVP is strongly dependent on the reaction conditions such as temperature, the amount of PVP, and reaction time. The results demonstrated that the keys for selective synthesis of Te nanobelts and nanowires are to modulate the growth rates of (100), (101), and (110) planes in the presence of PVP and to precisely control the reaction kinetics. High-quality luminescent ultrathin t-Te nanowires with a diameter of 4-9 nm display strong luminescent emission in the blue-violet region. This approach provides a facile route for the production of high-quality tellurium nanostructures with an interesting optical property. Furthermore, the synthesized ultrathin nanowires with deep blue color and nanobelts in gray color by this approach can be well dispersed in water or ethanol, making it possible for further engineering of their surfaces to prepare other hybrid core-shell nanostructures.

Well-defined silver/cross-linked-poly(vinyl alcohol) (PVA) sub-microcables, which were synthesized from a hydrothermal reaction using AgCl and PVA as precursors, have been used as sacrificial templates to fabricate gold/cross-linked-PVA sub-microcables by etching the silver/cross-linked-PVA sub-microcables with tetrachloroaurate(III). In addition, well-defined cross-linked-PVA sub-microtubes/sub-microfibers can also be produced by the removal of the silver cores of such sub-microcables at ambient temperature. The channel diameter and the shell thickness could be tuned by controlling the diameter of the core sub-microfibers and the shell thickness of the precursor sub-microcables. These cross-linked-PVA-based cables, tubes, and fibers have the potential to be used in future applications such as nanodevices.

A facile green chemistry carbonization method has been discovered for the synthesis of uniform silver@carbon rich composite (carbon and cross-linked polyvinyl alcohol) core-shell sub-microcables in large quantities, where the carbon sources such as glucose-based saccharides have played important roles in the formation of these novel sub-microcables.