Scalable Preparation of SrTiO_3 Submicro-wires from Layered Titanate Nanowires

SrTiO3 submicro-wires were prepared by the reaction of layered titanatc nanowircs with Sr（OH）2 powder in an autoclave. The wires were investigated using X-ray diffraction （XRD）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, Ultra-violet visible （UV-vis）, photoluminescence （PL） and Raman spectroscopy. The XRD measurement shows that the prepared SrTiO3 submicro-wircs hardly have impurity phases. The SEM and TEM images demonstrate that the scalable wires, which need to be processed at the reaction temperature of 180℃ for about 48 hours, are not composed of single crystals. The PL shows that the wire-like SrTiO3 has emission peaks at the wavelengths of 568 and 585 nm. Further, the Raman spectroscopy reveals structural changes in the products through different reaction time.

Facile Synthesis,Crystal Structure,and Adsorption Property of Small Titanate Nanowires

Small titanate nanowires with NaTi2O4（OH） formulation were directly synthesized via the hydrothermal reaction of amorphous titanate particles with concentrated Na OH solution.The average width of these nanowires is smaller than 20 nm,and the surface area is higher than 200 m-2/g.Compared with the larger nanowires obtained by the hydrothermal treatment of crystalline titania in alkaline solution,these small nanowires exhibit larger adsorption capacities and faster adsorption rate in the removal of both heavy metal ions and dyes.

Understanding Formation Mechanism of Titanate Nanowires through Hydrothermal Treatment of Various Ti-Containing Precursors in Basic Solutions

Titanate nanowires prepared by hydrothermal treatment of Ti02 in NaOH solution have attracted intensive attentions, but the formation mechanism is still under debate. Herein, we report an in-depth study on the formation mechanism through investigating the hydrothermal behavior of various Ti-containing precursors in basic solutions, including Ti, TiN, TiO2, Ti2SnC and Ti2AIN. Based on the results by means of X-ray diffraction （XRD）, transmission electron microscopy （TEM） and Raman spectroscopy, it is demonstrated that the crystal structure of the hydrothermal products is irrespective to the structure of the precursors or the types of basic solution （NaOH or KOH） in use. Alkali ions play an important role in the formation of titanate nanowires. The formation mechanism of the resultant titanate nanowires was proposed to be dissolution-crystallization mechanism.

Ag-modified hydrogen titanate nanowire arrays for stable lithium metal anode in a carbonate-based electrolyte

In the investigation of the next-generation battery anode,Li metal has attracted increasing attention owing to its ultrahigh specific capacity and low reduction potential.However,its low columbic efficiency,limited cycling life,and serious safety hazards have hindered the practical application of rechargeable Li metal batteries.Although several strategies have been proposed to enhance the electrochemical performance of Li metal anodes,most are centered around ether-based electrolytes,which are volatile and do not provide a sufficiently large voltage window.Therefore,we aimed to attain stable Li deposition/stripping in a commercial carbonate-based electrolyte.Herein,we have successfully synthesized hydrogen titanate(HTO)nanowire arrays decorated with homogenous Ag nanoparticles(NPs)(Ag@HTO)via simple hydrothermal and silver mirror reactions.The 3 D cross-linked array structure with Ag NPs provides preferable nucleation sites for uniform Li deposition,and most importantly,when assembled with the commercial LiNi_(0.5)Co0.2Mn_(0.3)O_(2) cathode material,the Ag@HTO could maintain a capacity retention ratio of 81.2% at 1 C after 200 cycles,however the pristine Ti foil failed to do so after only 60 cycles.Our research therefore reveals a new way of designing current collectors paired with commercial high voltage cathodes that can create high energy density Li metal batteries.

A comparative study on emergent pollutants photo-assisted degradation using ruthenium modified titanate nanotubes and nanowires as catalysts

Several methods have been used to tailor nanomaterials structure and properties.Sometimes,slight changes in the structure outcomes expressive improvements in the optical and photocatalytic properties of semiconductor nanoparticles.In this context,the influence of the metal doping and the morphology on a catalyst performance was studied in this work.Here,ruthenium doped titanate nanotubes(RuTNT)were synthesised for the first time using an amorphous Ru-containing precursor.Afterwards,the photocatalytic performance of this sample was compared to the one obtained for ruthenium titanate nanowires(RuTNW),recently reported.Two samples,RuTNW and RuTNT,were produced using the same Ru-containing precursor but distinct hydrothermal methodologies.The powders were structural,morphological and optical characterized by X-ray diffraction and fluorescence,transmission electron microscopy,Raman,X-ray photoelectron and photoluminescence spectroscopies.Distinct variations on the structural and optical properties of the RuTNT and RuTNW nanoparticles,due to ruthenium incorporation were observed.Their potential use as photocatalysts was evaluated on the hydroxyl radical photo-assisted production.Both samples were catalytic for this reaction,presenting better performances than the pristine counterparts,being RuTNT the best photocatalyst.Subsequently,the degradation of two emergent pollutants,caffeine and sulfamethazine,was studied.RuTNT demonstrated to be better photocatalyst than RuTNW for caffeine but identical performances were obtained for sulfamethazine.For both catalysts,the degradation mechanism of the pollutants was explored through the identification and quantification of the intermediate compounds produced and several differences were found.This indicates the importance of the structural and morphological aspects of a material on its catalytic performance.

Preparation and characterization of Li_(4)Ti_(5)O_(12) synthesized using hydrogen titanate nanowire for hybrid super capacitor

The electrical characteristics of hybrid super capacitor were evaluated by synthesizing LTO(Li_(4)Ti_(5)O_(12))using TiO_(2) having a hydrogen titanate nanowire form.Preparation of the hydrogen titanate nanowire was implemented by using TiO_(2) having size of 60 nm and NaOH,and performing synthesis at 70℃for 6 h with a sonochemical method.LTO compound was synthesized at 150℃for 36 h and at 180℃for 36 h respectively by using the hydrogen titanate nanowire and LiOH·H2O as starting materials with a hydrothermal method.The final LTO compound was synthesized at 700℃for 6 h using a solid-state method.As a result of manufacturing the hybrid super capacitor using LTO synthesized at 180℃for 36 h with the hydrothermal method,a capacity of 198 mA·h/g has been achieved compared to a theoretical capacity of 172 mA·h/g of existing LTO,and thus,the capacity has been increased by about 13%.Further,such excellent cycle performance has ensured its possibility as a high-capacity capacitor.