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A novel multi-functional CNT/ZnO/TiO 2 nano-composite ultrafiltration (UF) membrane was successfully synthesized via hydrothermal synthesis and acid treatment with the aid of ultra-sonication. Hydrothermally synthesized TiO 2 nanowires acted as the supporting matrix and the acid treated CNT/ZnO nanorods exhibited bridging characteristics to compose a “ cob-web ” like hierarchically structured nanocomposite material. This CNT/ZnO/TiO 2 nanocomposite UF membrane integrated the advantages of semiconductors and carbon based nanomaterials to be endowed high mechanical strength along with high photocatalytic capability as thus leading to producing clean water at a high membrane flux with low fouling potential. [ABSTRACT FROM AUTHOR]

Abstract: A general method for the fabrication of flexible, multifunctional and hierarchically-nanostructured membranes was reported. As an example, the as-prepared TiO2 nanorod self-supporting membrane shows excellent advantages, when it is used in concurrent filtration and degradation of the pollutants in waters, including high mechanical flexibility, high permeate flux, high photocatalytic activity and no membrane fouling problem, which indicate its great potential for sustainable environmental applications. And this general method also was successfully demonstrated with a ZnO nanoflake self-supporting membrane, which also have great potential in environmental and energy applications. [Copyright &y& Elsevier]

We report a facile non-hydrothermal method for the large-scale production of hierarchical TiO2 nanorod spheres for the photocatalytic elimination of contaminants and killing bacteria. Crescent Ti/RF spheres were prepared by deliberately adding titanium trichloride (TiCl3) to the reaction of resorcinol (R) and formaldehyde (F) in an open reactor under heating and stirring. The hierarchical TiO2 nanorod spheres were obtained by calcining the crescent Ti/RF spheres in a furnace in air to burn off the RF spheres. This method has many merits, such as large-scale production, good crystallisation of TiO2, and good reproducibility, all of which are difficult to realise by conventional hydrothermal methods. The calcination temperature plays a significant role in influencing the morphology, crystallisation, porosity, Brunauer-Emmett-Teller (BET) specific surface area, and hierarchy of the TiO2 nanorod spheres, thus resulting in different photocatalytic performances under UV light and solar light irradiation. The experimental results have demonstrated that the hierarchical TiO2 nanorod spheres obtained after calcination of the crescent Ti/RF spheres at different temperatures displayed similar photocatalytic activities under irradiation with UV light. We attribute this to a balance of opposing effects of the investigated factors. A higher calcination temperature leads to greater light absorption capability of the TiO2 nanorod spheres, thus resulting in higher photocatalytic antibacterial activity under solar light irradiation. It is also interesting to note that the hierarchical TiO2 nanorod spheres displayed intrinsic antibacterial activity in the absence of light irradiation, apparently because their sharp outward spikes can easily pierce and penetrate the walls of bacteria. In this study, the sharpest hierarchical TiO2 nanorod spheres were obtained after calcination at 500 °C, and these exhibited the highest antibacterial activity without light irradiation. A higher calcination temperature proved detrimental to the sharpness of the TiO2 nanorods, thus reducing their intrinsic antibacterial activity. [ABSTRACT FROM AUTHOR]

Here, hierarchical ZnO nanoflake spheres were hydrothermally synthesized at a large scale. These hierarchical ZnO nanoflake spheres were well characterized and successfully assembled on a piece of polymer membrane surface to form a multifunctional membrane with a “win-win” aim to realize the mitigation of membrane fouling and reuse of catalysts. This newly developed membrane demonstrated the removal ability of high pollutants via filtration, photodegradation of pollutants, and antibacterial growth under visible light irradiation. At the same time, this novel membrane holds the potential to produce clean water at a constant high flux. [ABSTRACT FROM PUBLISHER]

Abstract: Here, hierarchically meso/nanoporous TiO2 was successfully fabricated by a facile and efficient hydrolysis and calcination method using Ti(OC4H9)4 and K2S2O8 as precursors. The hydrosol was firstly prepared by drop-wise adding ethanol dissolved Ti(OC4H9)4 solution into acetone dissolved K2S2O8 solution under a vigorous stirring and heating condition. After being sufficiently hydrolyzed, the hydrosol was calcined to promote the crystallization of TiO2 and successfully dope S and C on TiO2. The calcination temperature significantly affects the doping of S and C on TiO2, crystallization of TiO2, formation of hierarchically meso/nanoporous structure of TiO2 and its light absorption capability. The S- and C-codoped TiO2 exhibits high photocatalytic H2 generation efficiency in a water/methanol sacrificial reagent system under the irradiation of UV light. The high photocatalytic efficiency is dependent on the comprehensively competing effects of the codoping of S and C, crystallization, specific surface area and light absorption capability. The S- and C-codoped TiO2 calcined at 600°C demonstrates the highest photocatalytic H2 generation efficiency, which is ascribed to the balanced synergy of the abovementioned factors. [Copyright &y& Elsevier]

Abstract: The effect of fabrication method on the properties of hierarchical 3D TiO2 nanostructures was investigated by employing and developing both hydrothermal method and calcination method to synthesize hierarchical 3D TiO2 nanorod spheres in this study. A comprehensive comparison in terms of morphologies, crystallization, specific surface areas, light absorption capabilities, and photoluminescence spectrum was conducted between 3D TiO2 nanorod spheres synthesized via hydrothermal method and that synthesized via calcination method. A better photocatalytic activity was demonstrated over the TiO2 nanorod spheres synthesized through calcination method. This was ascribed to the better crystallization and monodispersion of the hierarchical 3D TiO2 nanorod spheres resulted from the calcination method; thus rendering it with more superior characteristics such as larger specific surface area, enhanced light absorption capability and faster transfer of electrons which suppress the recombination of photogenerated electrons and holes. This study is thus significant not only in promoting the development of hierarchical 3D TiO2 nanorod spheres via different methods, but also in revealing the effect of fabrication method on the photocatalytic activity of hierarchical 3D TiO2 nanorod spheres. The calcination method is proposed to be a facile and promising method for scale-up production of the hierarchical 3D TiO2 nanorod spheres with high photocatalytic activity for efficient pollutants degradation. [Copyright &y& Elsevier]

Abstract: A novel photocatalyst was designed from the inspiration of natural forest''s high efficient on light harvesting and energy conversion. This novel “forest-like” photocatalyst was successfully synthesized by a facile continuously-conducted three steps methods: electrospinning TiO2 nanofiber acts as the trunks, hydrothermal growth ZnO nanorods on the surface of TiO2 nanofiber acts as the branches, while photodeposition of Cu nanoparticles on the surface of TiO2 nanofiber and ZnO nanorods act as the leaves. This novel photocatalyst demonstrated higher photocatalytic hydrogen generation rate than most of semiconductor catalysts and many newly developed catalysts such as Pt/TiO2 catalyst and artificial leaves Pt/N–TiO2 catalyst in a water/methanol sacrificial reagent system under the light irradiation as a result of its enhanced light absorption ability, enlarged specific surface area promoting mass transfer and providing more reaction sites and its potential on anti-recombination of electrons and holes. Meanwhile, it is interesting to note that the photocatalytic hydrogen generation activity has a liner relationship with the hierarchy of materials, which means higher hierarchy materials display higher photocatalytic hydrogen generation activity. It is reasonable to believe that this natural mimic photocatalyst without noble metals will benefit the energy generation and novel materials development. [Copyright &y& Elsevier]

Abstract: Through hydrothermally growing SrTiO3 cubics on the surface of electrospun TiO2 nanofibers, SrTiO3/TiO2 nanofibers heterostructures were successfully fabricated in the present study. This process is able to ensure uniform distribution of SrTiO3 on the surface of TiO2 nanofibers and lead to close contact between SrTiO3 and TiO2, which is beneficial for the fast separation of photogenerated electrons and holes so as to suppress the recombination of photogenerated electrons and holes at the interphase of SrTiO3 and TiO2. Besides this, the long 1D fibrous structure easy for electron transfer, the hierarchical structure promoting mass transfer and allowing more light reflection and absorption, and the large specific surface area providing more reactions sites to facilitate the reactants to desired oxidation places all together create a synergistic effect on improving the photocatalytic activity of the hierarchical SrTiO3/TiO2 nanofibers heterostructures. Under the irradiation of UV light, in a water/methanol sacrificial reagent system, the SrTiO3/TiO2 nanofibers heterostructures generate five times more H2 than bare TiO2 nanofibers because of its high photocatalytic activity. [Copyright &y& Elsevier]

Abstract: Innovative TiO2/SnO2 nanofibers were fabricated via electrospinning an innovated precursor solution and used for photocatalytic H2 generation. The nanofibers exhibited greatly enhanced H2 evolution rate compared to bare TiO2 nanofiber and P25. The enhanced efficiency of the TiO2/SnO2 nanofibers was attributed to its excellent synergistic properties: (1) its good mesoporosity; (2) the red-shift of absorbance spectra to enhance light absorbance capability; (3) its long nanofibrous structure and (4) anatase TiO2 – rutile TiO2 – rutile SnO2 ternary junctions favorable for the separation of electrons and holes. Based on our experimental results, the optimum ratio of TiO2/SnO2 nanofibers with 3% Sn demonstrated the highest efficiency in H2 generation. [Copyright &y& Elsevier]

Abstract: Currently, the biggest challenge for filtration membrane application is the severe membrane fouling problem, which consequently results in low flux and high energy cost. Herein, a novel kind of multifunctional membrane was fabricated via integrating the advantages of conventional polymer membrane as supporting layer and “forest” like hierarchically structured TiO2/ZnO nanomaterials as functional layer. This membrane has shown multifunctional properties, such as, high photocatalytic activity, high flux and high antibacterial capacity, which make it as a good candidate to tackle the challenge of producing clean water at a constant high flux with no membrane fouling problem and energy saving manner. The outstanding performance of this novel membrane would bring enough benefits to filtration membrane industry for clean water production and environmental protection. [Copyright &y& Elsevier]

Abstract: Novel high efficient photocatalyst is the key for photocatalytic hydrogen generation from water splitting. In this study, a novel hierarchical CuO/ZnO “corn-like” architecture was designed and synthesized via a combination of hydrothermal and photodeposition method. The as-prepared nanostructured materials was shown to effectively generate hydrogen in the mixture of methanol and water (v/v = 1:10). This is because the hierarchical CuO/ZnO “corn-like” architecture: 1) greatly enhances the light utilization rate due to its special architecture, 2) enlarges the specific surface area, providing more reaction sites and promoting mass transfer, 3) promotes the photogenerated electrons transfer from ZnO to CuO, achieving the anti-recombination effect of electrons and holes, and 4) avoids the photocorrosion of ZnO to improve the stability of ZnO as a catalyst during water splitting. Moreover, the novel hierarchical CuO/ZnO “corn-like” architecture is easily recovered for reuse. [Copyright &y& Elsevier]

Abstract: Hierarchical porous TiO2 hollow microspheres were synthesized by a facile approach from a one-step template method. This novel approach avoids tedious multiple steps from conventional template method for fabricating hierarchical porous and hollow microspheres. The as-prepared microspheres were characterized by XRD, SEM, TEM, nitrogen adsorption, and UV–vis DRS. Its photocatalytic activity was demonstrated in the photocatalytic degradation of Rhodamine B. Structural characterization indicates that the as-prepared microspheres had a hollow interior and a hierarchical porous structure with both large and small mesopores on its surface. The average diameters and BET surface areas of the hierarchical porous TiO2 hollow microspheres were 1.5μm and 117m2/g, respectively. Optical adsorption investigation shows that the hierarchical porous TiO2 hollow microspheres possessed the optical band gap of 3.42eV. A possible formation mechanism for the hierarchical porous TiO2 hollow microspheres was discussed. The hierarchical porous TiO2 hollow microspheres exhibited much higher photocatalytic activity than the commercial P25 TiO2. In addition, the as-prepared microspheres can be easily recycling for reuse. All these advantages show a bright future for this microspheric photocatalyst in environmental purification. [Copyright &y& Elsevier]

A novel TiO2nano-thorn membrane was assembled for concurrent filtration and photocatalytic oxidization to remove pollutants in water. This membrane has hierarchical porous and multifunctional properties, which provide these advantages: (1) producing water with high quality; (2) increasing water flux; and (3) eliminating membrane fouling. [ABSTRACT FROM AUTHOR]

A novel TiO2nano-thorn membrane was assembled for concurrent filtration and photocatalytic oxidization to remove pollutants in water. This membrane has hierarchical porous and multifunctional properties, which provide these advantages: (1) producing water with high quality; (2) increasing water flux; and (3) eliminating membrane fouling. [ABSTRACT FROM AUTHOR]

Abstract: A facile polyol synthesis was used for the deposition of Ag nanoparticles on electrospun TiO2 nanofibers for the subsequent fabrication of Ag/TiO2 nanofiber membrane. The permeate flux of the Ag/TiO2 nanofiber membrane was remarkably high compared to commercial P25 deposited membrane. The Ag/TiO2 nanofiber membrane achieved 99.9% bacteria inactivation and 80.0% dye degradation under solar irradiation within 30 min. The Ag/TiO2 nanofiber membrane also showed excellent antibacterial capability without solar irradiation. Considering the excellent intrinsic antibacterial activity and high-performance photocatalytic disinfection/degradation under solar irradiation, this novel membrane proved to have promising applications in water purification industry. [Copyright &y& Elsevier]

Abstract: Here we present a simple two-phase assembling method to produce high-quality graphene oxide–TiO2 nanorod composites (GO–TiO2 NRCs) on gram scale. TiO2 nanorods dispersed in toluene are synthesized from a facile two-phase hydrothermal method. The effective attachment of TiO2 nanorods on the whole GO sheets at the water–toluene interface is confirmed by Transmission Electron Microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The as-synthesized TiO2 nanorods show a slightly higher efficiency in the photocatalytic degradation of C. I. Acid Orange 7 (AO 7) irradiated under UV light (λ =254nm) and higher antibacterial activity under simulated sunlight than that of TiO2 nanoparticles with the same diameter. After combined with graphene oxide (GO), the GO–TiO2 NRCs show much higher photocatalytic activities than that of TiO2 nanorods alone and the GO–TiO2 nanoparticle composites (GO–TiO2 NPCs). The ratio of TiO2 and GO has no evident effect on the photocatalytic activity of GO–TiO2 NRCs when all the TiO2 nanorods are anchored on the GO sheets. The higher photocatalytic activity of GO–TiO2 NRCs is ascribed to the anti-charge recombination and the more (101) facets. Considering the superior photocatalytic activity of GO–TiO2 NRCs and the fact that they can been easily mass-produced, we expect this material may find important applications in environmental engineering and other fields. [Copyright &y& Elsevier]

Abstract: One-dimensional mesoporous TiO2 nanotube (TNT) with large specific surface area was successfully fabricated, and employed in removal of Acid Orange 7 (AO7) via adsorption and heterogeneous photocatalysis. As compared to its precursor, P25 (Degussa), TNT exhibited superior adsorption ability and photocatalytic activity. It was found that the amount of adsorbed dye over TNT surface was critical to the photodegradation efficiency of AO7, and adsorption was further controlled by solution pH and co-existing ions. With an increase in pH, adsorption of AO7 decreased rapidly, and adsorption behavior transformed from monolayer adsorption to asymmetric physisorption. Under low pH conditions, multivalent anions in high concentrations severely limited AO7 adsorption on TNT; whereas the increase of pH led to a less severe inhibition of the adsorption. On the other hand, multivalent cations seem to facilitate adsorption, regardless of pH conditions. Adsorption mechanism and photodegradation kinetics of AO7 on TNT were also discussed in the paper in view of paving the way for efficient dye wastewater treatment with the application of TNT photocatalyst. [Copyright &y& Elsevier]

Abstract: Efficient Cu incorporated TiO2 (Cu–TiO2) photocatalysts for hydrogen generation were fabricated by four methods: in situ sol–gel, wet impregnation, chemical reduction of Cu salt, and in situ photo-deposition. All prepared samples are characterized by good dispersion of Cu components, and excellent light absorption ability. Depending on the preparation process, hydrogen generation rates of the as-prepared Cu–TiO2 were recorded in the range of 9–20mmolh−1 gcatalyst −1, which were even more superior to some noble metal (Pt/Au) loaded TiO2. The various fabrication methods led to different chemical states of Cu, as well as different distribution ratio of Cu between surface and bulk phases of the photocatalyst. Both factors have been proven to influence photocatalytic hydrogen generation. In addition, the Cu content in the photocatalyst played a significant role in hydrogen generation. Among the four photocatalysts, the sample that was synthesized by in situ sol–gel method exhibited the highest stability. High efficiency, low cost, good stability are some of the merits that underline the promising potential of Cu–TiO2 in photocatalytic hydrogen generation. [Copyright &y& Elsevier]