Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolu...Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.展开更多
TiO2 nanotube arrays （TNTs） electrode loaded with Zn nanoparticles was prepared by anodization and the size of Zn nanoparticle loaded on TNTs electrode was controlled by chronoamperometry deposition time. Results of...TiO2 nanotube arrays （TNTs） electrode loaded with Zn nanoparticles was prepared by anodization and the size of Zn nanoparticle loaded on TNTs electrode was controlled by chronoamperometry deposition time. Results of SEM and XRD analysis show that Zn nanoparticles had a diameter of about 15-25 nm when the deposition time was 3-5 s. The UV-Vis diffuse reflectance spectra show the Zn loaded harvest light with 480-780 nm more effectively than the unloaded sample. The photocurrent response of Zn loaded TNTs electrodes were studied, the results showed that TNTs electrodes loaded with Zn nanoparti-cles has 50% increased photocurrent response under high-pressure mercury lamp irradiation compared with unloaded TNTs electrode.展开更多
Vertically orientated TiO2 nanotube array with diameters ranging from 60 up to 80 nm and length of 4 μm was grown on titanium by anodization.Crack initiation,propagation and saturation were studied using the substrat...Vertically orientated TiO2 nanotube array with diameters ranging from 60 up to 80 nm and length of 4 μm was grown on titanium by anodization.Crack initiation,propagation and saturation were studied using the substrate straining test.The results show that annealing obviously modifies the interfaces.With the increase of tensile strain,cracks in TiO2 nanotube films propagate rapidly and reach the saturation within a narrow strain gap.Interfacial shear strengths of TiO2 nanotube films without annealing,with 250 ℃ annealing and with 400 ℃ annealing can be estimated as 163.3,370.2 and 684.5 MPa,respectively.The critical energy release rates of TiO2 nanotube films are calculated as 49.6,102.6 and 392.7 J/m2,respectively.The fracture toughnesses of TiO2 nanotube films are estimated as 0.996,1.433 and 2.803 MPa-m1/2,respectively.The interfacial bonding mechanism of TiO2 nanotube film is chemical bonding.展开更多
Anodization is a popular method of preparing TiO2nanotube array films（TiNTs） by using direct current（DC）power as the driving voltage.In this study,three driving voltage modes,namely,the sine alternating current（s...Anodization is a popular method of preparing TiO2nanotube array films（TiNTs） by using direct current（DC）power as the driving voltage.In this study,three driving voltage modes,namely,the sine alternating current（sine） mode,the full-wave rectification of sine waves via four diodes（sine-4D,where D means diode） mode,and the DC mode,were used to prepare TiNTs by anodization.At 20 V,TiNTs were formed under sine-4D mode but only irregular porous TiO2films were formed under DC mode.At 50 V,TiNTs formed under both the sine-4D and DC modes.No TiNTs formed in the sine mode anodization at either 20 or 50 V.Compared with the DC mode,the sine-4D mode required a lower oxidation voltage for TiNT formation,which suggests that sine-4D is an economical,convenient,and efficient driving voltage for TiNT preparation by anodization.The morphologies and structures of TiNT samples anodized at 50 V in the sine-4D and DC modes at different oxidation time（1,5,10,30,60,and 120 min） were analyzed.TiNT growth processes were similar between the studied modes.However,the growth rate of the films was faster under the sine-4D mode than the DC mode during the first 30 min of anodization.展开更多
Curvature method was used to measure the residual stress and substrate straining tensile test was carried out to study the debonding behavior of TiO2 nanotube film. The results indicate that the internal residual stre...Curvature method was used to measure the residual stress and substrate straining tensile test was carried out to study the debonding behavior of TiO2 nanotube film. The results indicate that the internal residual stress is -54 MPa. The strains of debonding initiation of TiO2 nanotube films without annealing, with 250 °C annealing and with 400 °C annealing are 2.6%, 5.1% and 8.6%, respectively, and the average radii of the debonding patches with debonding initiation are 27.5, 17.1 and 19.4 μm, respectively. The true critical debonding stresses of TiO2 nanotube films without annealing, with 250 °C annealing and with 400 °C annealing can be estimated as 220.4, 394.5 and 627.9 MPa, respectively. Interfacial shear lag model is modified and polynomial fitting equation of the interfacial shear strength of TiO2 nanotube film is demonstrated under debonding conditions. The modification and polynomial fitting are reliable since good agreement of the interfacial shear strengths after fitting is obtained compared with those results from the crack density analysis.展开更多
Substrate straining test was carried out to study the buckling pattern of TiO2 nanotube film. The results show that the tensile strains of buckling occurrence of TiO2 nanotube films without annealing, with 250 ℃ anne...Substrate straining test was carried out to study the buckling pattern of TiO2 nanotube film. The results show that the tensile strains of buckling occurrence of TiO2 nanotube films without annealing, with 250 ℃ annealing and with 400 ℃ annealing are 2.5%, 8.9% and 7.8%, respectively, which indicates the modifying effects of temperature annealing. Through the SEM observation, the critical buckling stresses of TiO2 nanotube films without annealing, with 250 ℃ annealing and with 400 ℃ annealing can be estimated as 180.4, 410.2 and 619.5 MPa, respectively. The critical buckling stress of TiO2 nanotube films with 250 ℃ annealing from AFM observation is estimated as 470.2 MPa, which indicates good agreement with the critical buckling stress from SEM observation. The true stress and the critical energy release rate of TiO2 nanotube film with 250 ℃ annealing are given as 840.3 MPa and 77.2 J/m2, respectively. Excellent agreement of the critical energy release rate of TiO2 nanotube film with 250 ℃ annealing in terms of buckling perspective and crack perspective is obtained.展开更多
TiO_2 nanotubes(TNTs) have drawn tremendous attention owing to their unique architectural and physical properties. Anodizing of titanium foil has proven to be the most efficient method to fabricate well-aligned TNTs,w...TiO_2 nanotubes(TNTs) have drawn tremendous attention owing to their unique architectural and physical properties. Anodizing of titanium foil has proven to be the most efficient method to fabricate well-aligned TNTs,which, however, usually produces amorphous TNTs and needs further thermal annealing. Recently, a water-assisted crystallization strategy has been proposed and investigated by both science and engineering communities. This method is very efficient and energy saving, and it circumvents the drawbacks of thermal sintering approach. In this paper, we review the recent research progress in this kind of lowtemperature crystallization approach. Here, various synthetic methods are summarized, and the mechanisms of the amorphous–crystalline transformation are analyzed. The fundamental properties and applications of the low-temperature products are also discussed. Furthermore, it is proved that the water-assisted crystallization approach is not only applicable to TNTs but also to crystallizing other metal oxides.展开更多
A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffracti...A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.展开更多
TiO2 nanotube precursor was synthesized by the hydrothermal reaction of TiO2 powders with NaOH solution and the properties of the nanotube materials were tuned using different post-treatments. Transmission electron mi...TiO2 nanotube precursor was synthesized by the hydrothermal reaction of TiO2 powders with NaOH solution and the properties of the nanotube materials were tuned using different post-treatments. Transmission electron microscopic （TEM） observation revealed that the nanotube could be obtained by either a direct rinse with acid solution or rinse with distilled water followed by acid solution. The results of X-ray diffraction （XRD） and inductively coupled plasma （ICP） analysis indicated that the nanotube material was composed of H2Ti2O5·H2O. In addition, the photocatalytic activities of the resulting catalysts were found to be strongly dependent on the post-treatment. The results of the photocatalytic reaction showed that the degradation of Acid-red 3B dye fitted pseudo-zero-order kinetics and TiO2 nanotube prepared under direct rinse with acid solution exhibited a higher catalytic efficiency compared to other catalysts.展开更多
The process, that the polycrystalline TiO2 powders were converted into TiO2 nanotubes, was observed with transmission electron microscope. The results obtained indicated that in concentrated NaOH aqueous solution, an...The process, that the polycrystalline TiO2 powders were converted into TiO2 nanotubes, was observed with transmission electron microscope. The results obtained indicated that in concentrated NaOH aqueous solution, anisotropic swelling appears on the polycrystalline TiO2 granula at first, and then the nanotubes are formed.展开更多
This paper developed a fluorometric method for the sensitive determination of nonylphenol in water samples by preconcentration with zirconium doped titanium dioxide nanotubes solid phase extraction.The parameters on e...This paper developed a fluorometric method for the sensitive determination of nonylphenol in water samples by preconcentration with zirconium doped titanium dioxide nanotubes solid phase extraction.The parameters on extraction that would influence the enrichment performance such as the kind and volume of eluent,sample pH,sample flow rate,and sample volume were optimized in detail.Under the optimal conditions,the proposed method provided an excellent linear range of 1-150 mg/L and good LOD of 0.076 mg/L.The relative standard deviation（RSD,n = 6） was 2.8%.Proposed method was also used for the analysis of real water samples and the spiked recoveries were satisfied in the range of 98.7-103%.展开更多
Copper and titanium remain relatively plentiful in earth crust.Therefore,using them in solar energy conversion technologies are of significant interest.In this work,cuprous oxide（Cu2O）-modified short TiO2 nanotube a...Copper and titanium remain relatively plentiful in earth crust.Therefore,using them in solar energy conversion technologies are of significant interest.In this work,cuprous oxide（Cu2O）-modified short TiO2 nanotube array electrode was prepared based on the following two design ideas:first,the short titania nanotubes obtained from sonoelectrochemical anodization possess excellent charge separation and transportation properties as well as desirable mechanical stability;second,the sonoelectrochemical deposition technique favours the improvement in the combination between Cu2O and TiO2 nanotubes,and favours the dispersion of Cu2O particles.UV-Vis absorption and photo-electronchemical measurements proved that the Cu2O coating extended the visible spectrum absorption and the solar spectrum-induced photocurrent response.Under AM1.5 irradiation,the photocurrent density of the composite electrode（i.e.sonoelectrochemical deposition for 5 min） was more than 4.75 times as high as the pure nanotube electrode.Comparing the photoactivity of the Cu2O/TiO2 electrode obtained using sonoelectrochemical deposition with others that synthesized using plain electrochemical deposition,the photocurrent density of the former electrode was 2.2 times higher than that of the latter when biased at 1.0 V（vs.Ag/AgCl）.The reproducible photocurrent response under intermittent illumination demonstrated the excellent stability of the composite electrode.Such kind of composite electrode material will have many potential applications in solar cell and other fields.展开更多
We report a colloidal process to coat a layer of TiO2onto SiO2composite nanofibers containing embedded CdS and upconversion nanoparticles(UCNPs).The SiO2composite nanofibers were fabricated by electrospinning.To impro...We report a colloidal process to coat a layer of TiO2onto SiO2composite nanofibers containing embedded CdS and upconversion nanoparticles(UCNPs).The SiO2composite nanofibers were fabricated by electrospinning.To improve the energy transfer efficiency,UCNPs and CdS nanoparticles were bound in close proximity to each other within the SiO2matrix.β‐NaYF4:Yb(30%),Tm(0.5%)@NaYF4:Yb(20%),Er(2%)core–shell nanoparticles were used as nanotransducers for near infrared light.These nanoparticles exhibited enhanced upconversion fluorescence compared withβ‐NaYF4:Yb(30%),Tm(0.5%)orβ–NaYF4:Yb(30%),Tm(0.5%)@NaYF4nanoparticles.The morphologies,size and chemical compositions have been extensively investigated using field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X‐ray diffraction(XRD)and X‐ray photoelectron spectra(XPS),respectively.The TEM images showed that the TiO2composite nanotubes were embedded with a large amount of UCNPs and CdS nanoparticles.The composite TiO2nanotubes degraded more than90%of rhodamine B(RhB)dye during20min of irradiation by simulated solar light.In particular,more than50%of RhB was decomposed in70min,under irradiation of near infrared light(NIR).This high degradation was attributed to the full spectrum absorption of solar light,and the enhanced transfer efficiency for near infrared light.The as‐prepared nanostructures can harness solar energy,and provide an alternative to overcome energy shortages and environmental protection.展开更多
Controllable synthesis of insertion-type anode materials with beneficial micro-and nanostructures is a promising approach for the synthesis of sodium-ion storage devices with high-reactivity and excellent electrochemi...Controllable synthesis of insertion-type anode materials with beneficial micro-and nanostructures is a promising approach for the synthesis of sodium-ion storage devices with high-reactivity and excellent electrochemical performance.In this study,we developed a sacrificial-templating route to synthesize TiO_(2)@N-doped carbon nanotubes(TiO_(2)@NC-NTs)with excellent electrochemical performance.The asprepared mesoporous TiO_(2)@NC-NTs with tiny nanocrystals of anatase TiO_(2) wrapped in N-doped carbon layers showed a well-defined tube structure with a large specific surface area of 198 m^(2) g^(-1) and a large pore size of~5 nm.The TiO_(2)@NC-NTs delivered high reversible capacities of 158 m A h g^(-1) at 2 C(1 C=335 m A g^(-1))for 2200 cycles and 146 m A h g^(-1) at 5 C for 4000 cycles,as well as an ultrahigh rate capability of up to 40 C with a capacity of 98 m A h g^(-1).Even at a high current density of 10 C,a capacity of 138 m A h g^(-1) could be delivered over 10,000 cycles.Thus,the synthesis of mesoporous TiO_(2)@NC-NTs was demonstrated to be an efficient approach for developing electrode materials with high sodium storage and long cycle life.展开更多
TiO2 nanotube （TNT） arrays were fabricated by anodic oxidation of titanium foil in a fluoride- based solution, on which Cu20 particles were loaded via galvanostatic pulse electrodeposition in cupric acetate solution...TiO2 nanotube （TNT） arrays were fabricated by anodic oxidation of titanium foil in a fluoride- based solution, on which Cu20 particles were loaded via galvanostatic pulse electrodeposition in cupric acetate solutions in the absence of any other additives. The structure and optical properties of Cu2O-loaded TiO2 nanotube arrays （Cu2O-TNTs） were analyzed by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and UV-Vis absorption, and the photoelectrochemical performance was measured using an electrochemical work station with a three-electrode configuration. The results show that the Cu2O particles distribute uniformly on the highly ordered anatase TiO2 nanotube arrays. The morphologies of Cu2O crystals change from branched, truncated octahedrons to dispersive single octahedrons with increasing deposition current densities. The Cu2O- TNTs exhibited remarkable visible light responses with obvious visible light absorption and greatly enhanced visible light photoelectrochemical performance. The I-V characteristics under visible light irradiation show a distinct plateau in the region between approximately -0.3 and 0 V, resulting in higher open-circuit voltages and larger short-circuit currents with increased Cu2O deposition.展开更多
TiO_(2) nanotube arrays,growing on three-dimensional(3 D)porous Ti membrane,were synthesized using a facile nonsolvent-induced phase separation and anodization process.The length of those three-dimensional nanotube ar...TiO_(2) nanotube arrays,growing on three-dimensional(3 D)porous Ti membrane,were synthesized using a facile nonsolvent-induced phase separation and anodization process.The length of those three-dimensional nanotube arrays could be tuned by prolonging the anodizing time.When the anodizing time is 8 h,the three-dimensional TiO_(2) nanotube arrays/porous Ti electrode exhibits well cycling stability and ultra-high specific capacity,which is used in lithium-ion batteries,attributed to the high utilization rate of the substrate and the high growth intensity of the active materials.Three-dimensional TiO_(2) nano tube arrays/porous Ti electrode,at 100μA·cm^(-2) with 8 h anodizing time,shows a typical discharge plateau at 1.78 V and exhibits the specific capacity with 2126.7μAh·cm^(-2),The novel nanotube arrays@3 D porous architecture effectively shortens the electron/ion transmission path,which could pave way for optimizing the design of highperformance anode materials for next-generation energy storage system.展开更多
TiO2 nanotubes(NT)has been demonstrated its potential in orthopaedic applications due to its enhanced surface wettability and bio-osteointegration.However,the fretting biocorrosion is the main concern that limited its...TiO2 nanotubes(NT)has been demonstrated its potential in orthopaedic applications due to its enhanced surface wettability and bio-osteointegration.However,the fretting biocorrosion is the main concern that limited its successfully application in orthopaedic application.In this study,a structure optimised thin TiO2 nanotube(SONT)layer was successfully created on Ti6Al4V bone screw,and its fretting corrosion performance was investigated and compared to the pristine Ti6Al4V bone screws and NT decorated screw in a bone-screw fretting simulation rig.The results have shown that the debonding TiO2 nanotube from the bone screw reduced significantly,as a result of structure optimisation.The SONT layer also exhibited enhanced bio-corrosion resistance compared pristine bone screw and conventionally NT modified bone screw.It is postulated that interfacial layer between TiO2 nanotube and Ti6Al4V substrate,generated during structure optimisation process,enhanced bonding of TiO2 nanotube layer to the Ti6Al4V bone screws that leading to the improvement in fretting corrosion resistance.The results highlighted the potential SONT in orthopaedic application as bone fracture fixation devices.展开更多
The platinum nanoparticles supported on self-organized TiO2 nanotubes （Pt-TiO2/Ti） were prepared using electrochemical anodic oxidation followed by cathodic reduction. The structure and chemical nature of the Pt-TiO...The platinum nanoparticles supported on self-organized TiO2 nanotubes （Pt-TiO2/Ti） were prepared using electrochemical anodic oxidation followed by cathodic reduction. The structure and chemical nature of the Pt-TiO2/Ti electrocatalyst were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Both XRD and SEM results indicate the presence of platinum on nanotubular TiO2. The stability of the Pt deposits was also investigated in 0.5 mol/L H2SO4 solution by cyclic voltammetry. The electrocatalytic activity of the Pt-TiO2/Ti catalyst exhibits enhancement effect during electro-oxidation of methanol when annealed to anatase. Successive cyclic voltam- mograms of methanol oxidation on the Pt-TiO2/Ti electrocatalyst shows unique electrocatalytic characteristics when compared to methanol oxidation on the bulk Pt catalyst. This is because of further quick oxidation of adsorbed CO by Pt （111） facets of Pt particles on self-organized TiO2 nanotubes when the formation of an electroactive film onto the working catalyst surface occurs.展开更多
The highly ordered TiO2 nanotubes (NTs) were fabricated by the anodic oxidation method. Their morphology, structure and crystalline phase were characterized by scanning electron microscopy (SEM) and X-ray diffractomet...The highly ordered TiO2 nanotubes (NTs) were fabricated by the anodic oxidation method. Their morphology, structure and crystalline phase were characterized by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The effects of morphology, specific surface area, pore structures and photo catalytic activity of the TiO2 NTs were investigated. UV-vis spectra analysis showed that its light absorption had been extended to the visible light range. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic oxidation of gaseous HCHO and MB aqueous solution. The samples had better adhesion strength in the dark and showed a higher photocatalytic activity than nanoparticles. Especially, with ultraviolet light pretreatment, the nanotubes exhibited more stable active for photocatalytic decomposition and the photodecomposition rate remained at high level after 3 cycles of the photocatalysis experiment. Thus, how the number of surface active group center dot OH increased and the mechanism for the great improvement for the photocatalytic activity are discussed. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
We report the development of a novel visible response BiVO_4/TiO_2(N_2) nanotubes photoanode for photoelectrocatalytic applications. The nitrogen-treated TiO_2 nanotube shows a high carrier concentration rate, thus re...We report the development of a novel visible response BiVO_4/TiO_2(N_2) nanotubes photoanode for photoelectrocatalytic applications. The nitrogen-treated TiO_2 nanotube shows a high carrier concentration rate, thus resulting in a high efficient charge transportation and low electron–hole recombination in the TiO_2–BiVO_4. Therefore, the BiVO_4/TiO_2(N_2) NTs photoanode enabled with a significantly enhanced photocurrent of 2.73 mA cm^(-2)(at 1 V vs. Ag/Ag Cl) and a degradation efficiency in the oxidation of dyes under visible light. Field emission scanning electron microscopy, X-ray diffractometry, energy-dispersive X-ray spectrometer, and UV–Vis absorption spectrum were conducted to characterize the photoanode and demonstrated the presence of both metal oxides as a junction composite.展开更多
基金support from the European Union Horizon 2020 program(project HERMES,nr.952184)the Ministry of Education,Youth and Sports of the Czech Republic for supporting CEMNAT(LM2023037)+1 种基金Czech-NanoLab(LM2023051)infrastructures for providing ALD,SEM,EDX,XPS,TEM,and XRDCzech Science Foundation(project 23-08019X,EXPRO).
文摘Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.
基金ACKNOWLEDGMENTS This work was supported by the Science Foundation of Chongqing Science and Technology Committee （No.CSTS2009BB4047）, and Innovative Talent Training Project, the Third Stage of ＂211 Project＂ of Chongqing University （No.S-09109）.
文摘TiO2 nanotube arrays （TNTs） electrode loaded with Zn nanoparticles was prepared by anodization and the size of Zn nanoparticle loaded on TNTs electrode was controlled by chronoamperometry deposition time. Results of SEM and XRD analysis show that Zn nanoparticles had a diameter of about 15-25 nm when the deposition time was 3-5 s. The UV-Vis diffuse reflectance spectra show the Zn loaded harvest light with 480-780 nm more effectively than the unloaded sample. The photocurrent response of Zn loaded TNTs electrodes were studied, the results showed that TNTs electrodes loaded with Zn nanoparti-cles has 50% increased photocurrent response under high-pressure mercury lamp irradiation compared with unloaded TNTs electrode.
基金Project(50604017) supported by the National Natural Science Foundation of ChinaProject(20110946Z) supported by the State Key Laboratory of Powder Metallurgy,China
文摘Vertically orientated TiO2 nanotube array with diameters ranging from 60 up to 80 nm and length of 4 μm was grown on titanium by anodization.Crack initiation,propagation and saturation were studied using the substrate straining test.The results show that annealing obviously modifies the interfaces.With the increase of tensile strain,cracks in TiO2 nanotube films propagate rapidly and reach the saturation within a narrow strain gap.Interfacial shear strengths of TiO2 nanotube films without annealing,with 250 ℃ annealing and with 400 ℃ annealing can be estimated as 163.3,370.2 and 684.5 MPa,respectively.The critical energy release rates of TiO2 nanotube films are calculated as 49.6,102.6 and 392.7 J/m2,respectively.The fracture toughnesses of TiO2 nanotube films are estimated as 0.996,1.433 and 2.803 MPa-m1/2,respectively.The interfacial bonding mechanism of TiO2 nanotube film is chemical bonding.
基金the financial support provided by the National Natural Science Foundation of China (Nos. 21277004, 21190051 and 41121004)the Beijing Natural Science Foundation, China (No. 8132035)
文摘Anodization is a popular method of preparing TiO2nanotube array films（TiNTs） by using direct current（DC）power as the driving voltage.In this study,three driving voltage modes,namely,the sine alternating current（sine） mode,the full-wave rectification of sine waves via four diodes（sine-4D,where D means diode） mode,and the DC mode,were used to prepare TiNTs by anodization.At 20 V,TiNTs were formed under sine-4D mode but only irregular porous TiO2films were formed under DC mode.At 50 V,TiNTs formed under both the sine-4D and DC modes.No TiNTs formed in the sine mode anodization at either 20 or 50 V.Compared with the DC mode,the sine-4D mode required a lower oxidation voltage for TiNT formation,which suggests that sine-4D is an economical,convenient,and efficient driving voltage for TiNT preparation by anodization.The morphologies and structures of TiNT samples anodized at 50 V in the sine-4D and DC modes at different oxidation time（1,5,10,30,60,and 120 min） were analyzed.TiNT growth processes were similar between the studied modes.However,the growth rate of the films was faster under the sine-4D mode than the DC mode during the first 30 min of anodization.
基金Project (51274248) supported by the National Natural Science Foundation of ChinaProject (20110946Z) supported by the State Key Laboratory of Powder Metallurgy, China
文摘Curvature method was used to measure the residual stress and substrate straining tensile test was carried out to study the debonding behavior of TiO2 nanotube film. The results indicate that the internal residual stress is -54 MPa. The strains of debonding initiation of TiO2 nanotube films without annealing, with 250 °C annealing and with 400 °C annealing are 2.6%, 5.1% and 8.6%, respectively, and the average radii of the debonding patches with debonding initiation are 27.5, 17.1 and 19.4 μm, respectively. The true critical debonding stresses of TiO2 nanotube films without annealing, with 250 °C annealing and with 400 °C annealing can be estimated as 220.4, 394.5 and 627.9 MPa, respectively. Interfacial shear lag model is modified and polynomial fitting equation of the interfacial shear strength of TiO2 nanotube film is demonstrated under debonding conditions. The modification and polynomial fitting are reliable since good agreement of the interfacial shear strengths after fitting is obtained compared with those results from the crack density analysis.
基金Project (51274248) supported by the National Natural Science Foundation of ChinaProject (20110946Z) supported by State Key Laboratory of Powder Metallurgy, China
文摘Substrate straining test was carried out to study the buckling pattern of TiO2 nanotube film. The results show that the tensile strains of buckling occurrence of TiO2 nanotube films without annealing, with 250 ℃ annealing and with 400 ℃ annealing are 2.5%, 8.9% and 7.8%, respectively, which indicates the modifying effects of temperature annealing. Through the SEM observation, the critical buckling stresses of TiO2 nanotube films without annealing, with 250 ℃ annealing and with 400 ℃ annealing can be estimated as 180.4, 410.2 and 619.5 MPa, respectively. The critical buckling stress of TiO2 nanotube films with 250 ℃ annealing from AFM observation is estimated as 470.2 MPa, which indicates good agreement with the critical buckling stress from SEM observation. The true stress and the critical energy release rate of TiO2 nanotube film with 250 ℃ annealing are given as 840.3 MPa and 77.2 J/m2, respectively. Excellent agreement of the critical energy release rate of TiO2 nanotube film with 250 ℃ annealing in terms of buckling perspective and crack perspective is obtained.
基金financially supported by the National R&D Program of China under No.2017YFA0207400National Key Research and Development Plan under No.2016YFA0300801National Natural Science Foundation of China under Nos.51502033,61571079,61131005 and 51572042
文摘TiO_2 nanotubes(TNTs) have drawn tremendous attention owing to their unique architectural and physical properties. Anodizing of titanium foil has proven to be the most efficient method to fabricate well-aligned TNTs,which, however, usually produces amorphous TNTs and needs further thermal annealing. Recently, a water-assisted crystallization strategy has been proposed and investigated by both science and engineering communities. This method is very efficient and energy saving, and it circumvents the drawbacks of thermal sintering approach. In this paper, we review the recent research progress in this kind of lowtemperature crystallization approach. Here, various synthetic methods are summarized, and the mechanisms of the amorphous–crystalline transformation are analyzed. The fundamental properties and applications of the low-temperature products are also discussed. Furthermore, it is proved that the water-assisted crystallization approach is not only applicable to TNTs but also to crystallizing other metal oxides.
基金supported by the National Natural Science Foundation of China(21507104)Natural Science Basic Research Plan in Shaanxi Province of China(2017JM2015)~~
文摘A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.
文摘TiO2 nanotube precursor was synthesized by the hydrothermal reaction of TiO2 powders with NaOH solution and the properties of the nanotube materials were tuned using different post-treatments. Transmission electron microscopic （TEM） observation revealed that the nanotube could be obtained by either a direct rinse with acid solution or rinse with distilled water followed by acid solution. The results of X-ray diffraction （XRD） and inductively coupled plasma （ICP） analysis indicated that the nanotube material was composed of H2Ti2O5·H2O. In addition, the photocatalytic activities of the resulting catalysts were found to be strongly dependent on the post-treatment. The results of the photocatalytic reaction showed that the degradation of Acid-red 3B dye fitted pseudo-zero-order kinetics and TiO2 nanotube prepared under direct rinse with acid solution exhibited a higher catalytic efficiency compared to other catalysts.
基金This project was supported by the National Natural Science Foundation of China (20071010).
文摘The process, that the polycrystalline TiO2 powders were converted into TiO2 nanotubes, was observed with transmission electron microscope. The results obtained indicated that in concentrated NaOH aqueous solution, anisotropic swelling appears on the polycrystalline TiO2 granula at first, and then the nanotubes are formed.
文摘This paper developed a fluorometric method for the sensitive determination of nonylphenol in water samples by preconcentration with zirconium doped titanium dioxide nanotubes solid phase extraction.The parameters on extraction that would influence the enrichment performance such as the kind and volume of eluent,sample pH,sample flow rate,and sample volume were optimized in detail.Under the optimal conditions,the proposed method provided an excellent linear range of 1-150 mg/L and good LOD of 0.076 mg/L.The relative standard deviation（RSD,n = 6） was 2.8%.Proposed method was also used for the analysis of real water samples and the spiked recoveries were satisfied in the range of 98.7-103%.
基金the State Key Development Program for Basic Research of China (Grant No.2009CB220004)the Shanghai Basic Research Key Project (08JC1411300,0952nm01800)+1 种基金the National High Technology Research and Development Program of China (Grant No.2009 AA063003)Shanghai Tongji Gao Tingyao Environmental Science and Technology Development Foundation for financial support
文摘Copper and titanium remain relatively plentiful in earth crust.Therefore,using them in solar energy conversion technologies are of significant interest.In this work,cuprous oxide（Cu2O）-modified short TiO2 nanotube array electrode was prepared based on the following two design ideas:first,the short titania nanotubes obtained from sonoelectrochemical anodization possess excellent charge separation and transportation properties as well as desirable mechanical stability;second,the sonoelectrochemical deposition technique favours the improvement in the combination between Cu2O and TiO2 nanotubes,and favours the dispersion of Cu2O particles.UV-Vis absorption and photo-electronchemical measurements proved that the Cu2O coating extended the visible spectrum absorption and the solar spectrum-induced photocurrent response.Under AM1.5 irradiation,the photocurrent density of the composite electrode（i.e.sonoelectrochemical deposition for 5 min） was more than 4.75 times as high as the pure nanotube electrode.Comparing the photoactivity of the Cu2O/TiO2 electrode obtained using sonoelectrochemical deposition with others that synthesized using plain electrochemical deposition,the photocurrent density of the former electrode was 2.2 times higher than that of the latter when biased at 1.0 V（vs.Ag/AgCl）.The reproducible photocurrent response under intermittent illumination demonstrated the excellent stability of the composite electrode.Such kind of composite electrode material will have many potential applications in solar cell and other fields.
基金supported in part by the National Natural Science Foundation of China(21471043,21304028,51403195,31501576)~~
文摘We report a colloidal process to coat a layer of TiO2onto SiO2composite nanofibers containing embedded CdS and upconversion nanoparticles(UCNPs).The SiO2composite nanofibers were fabricated by electrospinning.To improve the energy transfer efficiency,UCNPs and CdS nanoparticles were bound in close proximity to each other within the SiO2matrix.β‐NaYF4:Yb(30%),Tm(0.5%)@NaYF4:Yb(20%),Er(2%)core–shell nanoparticles were used as nanotransducers for near infrared light.These nanoparticles exhibited enhanced upconversion fluorescence compared withβ‐NaYF4:Yb(30%),Tm(0.5%)orβ–NaYF4:Yb(30%),Tm(0.5%)@NaYF4nanoparticles.The morphologies,size and chemical compositions have been extensively investigated using field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),X‐ray diffraction(XRD)and X‐ray photoelectron spectra(XPS),respectively.The TEM images showed that the TiO2composite nanotubes were embedded with a large amount of UCNPs and CdS nanoparticles.The composite TiO2nanotubes degraded more than90%of rhodamine B(RhB)dye during20min of irradiation by simulated solar light.In particular,more than50%of RhB was decomposed in70min,under irradiation of near infrared light(NIR).This high degradation was attributed to the full spectrum absorption of solar light,and the enhanced transfer efficiency for near infrared light.The as‐prepared nanostructures can harness solar energy,and provide an alternative to overcome energy shortages and environmental protection.
基金the financial support provided by internal reseach funding of Khalifa University of Science and Technology,United Arab Emirates(Grant No.CIRA-2018-16)。
文摘Controllable synthesis of insertion-type anode materials with beneficial micro-and nanostructures is a promising approach for the synthesis of sodium-ion storage devices with high-reactivity and excellent electrochemical performance.In this study,we developed a sacrificial-templating route to synthesize TiO_(2)@N-doped carbon nanotubes(TiO_(2)@NC-NTs)with excellent electrochemical performance.The asprepared mesoporous TiO_(2)@NC-NTs with tiny nanocrystals of anatase TiO_(2) wrapped in N-doped carbon layers showed a well-defined tube structure with a large specific surface area of 198 m^(2) g^(-1) and a large pore size of~5 nm.The TiO_(2)@NC-NTs delivered high reversible capacities of 158 m A h g^(-1) at 2 C(1 C=335 m A g^(-1))for 2200 cycles and 146 m A h g^(-1) at 5 C for 4000 cycles,as well as an ultrahigh rate capability of up to 40 C with a capacity of 98 m A h g^(-1).Even at a high current density of 10 C,a capacity of 138 m A h g^(-1) could be delivered over 10,000 cycles.Thus,the synthesis of mesoporous TiO_(2)@NC-NTs was demonstrated to be an efficient approach for developing electrode materials with high sodium storage and long cycle life.
基金Funded by the National Natural Science Foundation of China(No.51175363)the Youth Staff Fund of Taiyuan University of Technology(Nos.K201016,K201013)+1 种基金the Specialized Fund for Innovative of College Students of Taiyuan City(No.09122018)the Program for Changjiang Scholar and Innovative Research Team in University(No.IRT0972)
文摘TiO2 nanotube （TNT） arrays were fabricated by anodic oxidation of titanium foil in a fluoride- based solution, on which Cu20 particles were loaded via galvanostatic pulse electrodeposition in cupric acetate solutions in the absence of any other additives. The structure and optical properties of Cu2O-loaded TiO2 nanotube arrays （Cu2O-TNTs） were analyzed by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and UV-Vis absorption, and the photoelectrochemical performance was measured using an electrochemical work station with a three-electrode configuration. The results show that the Cu2O particles distribute uniformly on the highly ordered anatase TiO2 nanotube arrays. The morphologies of Cu2O crystals change from branched, truncated octahedrons to dispersive single octahedrons with increasing deposition current densities. The Cu2O- TNTs exhibited remarkable visible light responses with obvious visible light absorption and greatly enhanced visible light photoelectrochemical performance. The I-V characteristics under visible light irradiation show a distinct plateau in the region between approximately -0.3 and 0 V, resulting in higher open-circuit voltages and larger short-circuit currents with increased Cu2O deposition.
基金the National Natural Science Foundation of China(Nos.51801136,51701142 and 51871165)Tianjin Municipal Education Committee Scientific Research Projects(No.2017KJ075)the Australian Research Council Discovery Project(No.DP200100965)。
文摘TiO_(2) nanotube arrays,growing on three-dimensional(3 D)porous Ti membrane,were synthesized using a facile nonsolvent-induced phase separation and anodization process.The length of those three-dimensional nanotube arrays could be tuned by prolonging the anodizing time.When the anodizing time is 8 h,the three-dimensional TiO_(2) nanotube arrays/porous Ti electrode exhibits well cycling stability and ultra-high specific capacity,which is used in lithium-ion batteries,attributed to the high utilization rate of the substrate and the high growth intensity of the active materials.Three-dimensional TiO_(2) nano tube arrays/porous Ti electrode,at 100μA·cm^(-2) with 8 h anodizing time,shows a typical discharge plateau at 1.78 V and exhibits the specific capacity with 2126.7μAh·cm^(-2),The novel nanotube arrays@3 D porous architecture effectively shortens the electron/ion transmission path,which could pave way for optimizing the design of highperformance anode materials for next-generation energy storage system.
基金financially supported by the European Union via the H2020-MSCA-RISE-2016 program(BAMOS Project,734156)Royal Society via the International Exchange Program(IE161349)+2 种基金Key Research Project from the National Key Research and Development Program of China(2016YFC1100401)National Natural Science Foundation of China(51705507)Young Elite Scientists Sponsorship Program by CAST(2017QNRC0181)。
文摘TiO2 nanotubes(NT)has been demonstrated its potential in orthopaedic applications due to its enhanced surface wettability and bio-osteointegration.However,the fretting biocorrosion is the main concern that limited its successfully application in orthopaedic application.In this study,a structure optimised thin TiO2 nanotube(SONT)layer was successfully created on Ti6Al4V bone screw,and its fretting corrosion performance was investigated and compared to the pristine Ti6Al4V bone screws and NT decorated screw in a bone-screw fretting simulation rig.The results have shown that the debonding TiO2 nanotube from the bone screw reduced significantly,as a result of structure optimisation.The SONT layer also exhibited enhanced bio-corrosion resistance compared pristine bone screw and conventionally NT modified bone screw.It is postulated that interfacial layer between TiO2 nanotube and Ti6Al4V substrate,generated during structure optimisation process,enhanced bonding of TiO2 nanotube layer to the Ti6Al4V bone screws that leading to the improvement in fretting corrosion resistance.The results highlighted the potential SONT in orthopaedic application as bone fracture fixation devices.
基金the 11th Five-Year Supporting Programs of Science and Technology (No. 2006BAD04A12)
文摘The platinum nanoparticles supported on self-organized TiO2 nanotubes （Pt-TiO2/Ti） were prepared using electrochemical anodic oxidation followed by cathodic reduction. The structure and chemical nature of the Pt-TiO2/Ti electrocatalyst were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Both XRD and SEM results indicate the presence of platinum on nanotubular TiO2. The stability of the Pt deposits was also investigated in 0.5 mol/L H2SO4 solution by cyclic voltammetry. The electrocatalytic activity of the Pt-TiO2/Ti catalyst exhibits enhancement effect during electro-oxidation of methanol when annealed to anatase. Successive cyclic voltam- mograms of methanol oxidation on the Pt-TiO2/Ti electrocatalyst shows unique electrocatalytic characteristics when compared to methanol oxidation on the bulk Pt catalyst. This is because of further quick oxidation of adsorbed CO by Pt （111） facets of Pt particles on self-organized TiO2 nanotubes when the formation of an electroactive film onto the working catalyst surface occurs.
基金financial support from Tianjin Science and Technology Support Plan Key Projects(NO.12ZCZDJC35600)
文摘The highly ordered TiO2 nanotubes (NTs) were fabricated by the anodic oxidation method. Their morphology, structure and crystalline phase were characterized by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The effects of morphology, specific surface area, pore structures and photo catalytic activity of the TiO2 NTs were investigated. UV-vis spectra analysis showed that its light absorption had been extended to the visible light range. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic oxidation of gaseous HCHO and MB aqueous solution. The samples had better adhesion strength in the dark and showed a higher photocatalytic activity than nanoparticles. Especially, with ultraviolet light pretreatment, the nanotubes exhibited more stable active for photocatalytic decomposition and the photodecomposition rate remained at high level after 3 cycles of the photocatalysis experiment. Thus, how the number of surface active group center dot OH increased and the mechanism for the great improvement for the photocatalytic activity are discussed. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金the National Nature Science Foundation of China(21507085,21576162)Shanghai Sailing Program of China(14YF1401500)for financial support
文摘We report the development of a novel visible response BiVO_4/TiO_2(N_2) nanotubes photoanode for photoelectrocatalytic applications. The nitrogen-treated TiO_2 nanotube shows a high carrier concentration rate, thus resulting in a high efficient charge transportation and low electron–hole recombination in the TiO_2–BiVO_4. Therefore, the BiVO_4/TiO_2(N_2) NTs photoanode enabled with a significantly enhanced photocurrent of 2.73 mA cm^(-2)(at 1 V vs. Ag/Ag Cl) and a degradation efficiency in the oxidation of dyes under visible light. Field emission scanning electron microscopy, X-ray diffractometry, energy-dispersive X-ray spectrometer, and UV–Vis absorption spectrum were conducted to characterize the photoanode and demonstrated the presence of both metal oxides as a junction composite.
