The surface of Titanium Hydride (TiH 2) is coated by Nano Titanium Dioxide (TiO 2) particles prepared in both of methods of hydrolysis reaction of Ti(OC 4H 9) 4 and base precipitation reaction of Ti(SO 4) 2. ...The surface of Titanium Hydride (TiH 2) is coated by Nano Titanium Dioxide (TiO 2) particles prepared in both of methods of hydrolysis reaction of Ti(OC 4H 9) 4 and base precipitation reaction of Ti(SO 4) 2. TiH 2 coated with nano TiO 2 particles, in which there is an oxidation film on its surface, shown in the experiments, will obviously achieve good effects on releasing hydrogen slowly in high temperature. There are different structures and properties of TiH 2 coated by nano TiO 2 particles prepared in different ways in high temperature, which can influence on releasing hydrogen.展开更多
The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and trib...The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6-12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.展开更多
The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are a...The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.展开更多
Barite/TiO2 composite particle (B/TCP) was prepared by coating TiO2 on the surfaces of barite particles through mechano-chemical method. The preparation parameters and pigment properties of B/TCP as well as the intera...Barite/TiO2 composite particle (B/TCP) was prepared by coating TiO2 on the surfaces of barite particles through mechano-chemical method. The preparation parameters and pigment properties of B/TCP as well as the interaction mechanism between barite and TiO2 were studied. The results indicated that the mechanical co-grinding process and the proportion of TiO2 affected the properties of B/TCP significantly. B/TCP prepared under optimal conditions was similar to TiO2 in pigment properties. It was mainly the strong electrostatic attraction between barite and TiO2 in water that combined them firmly and then formed B/TCP.展开更多
Doped and undoped TiCh nanoparticles were prepared by Stober method and thermally treated at 600 ℃.The effect of Nd^（3＋） ion on the structure and micro structure of anatase-phase TiCh nanocrystals was studied by R...Doped and undoped TiCh nanoparticles were prepared by Stober method and thermally treated at 600 ℃.The effect of Nd^（3＋） ion on the structure and micro structure of anatase-phase TiCh nanocrystals was studied by Rietveld refinement method using X-ray powder diffraction data.Bond lengths,bond angles,and edges distances were analyzed.The phase formation was confirmed by high-resolution transmission electron microscopy.The adjustment of Ti-0 bond length induced by the addition of Nd^（3＋） ions,reduced the octahedral distortion and altered the octahedral array in the anatase-phase TiCh nanocrystal.The changes of structure and microstructure were mainly observed for TiCh nanoparticles doped with 0.1 at.%of Nd^（3＋） ions and attributed to the cationic substitution of Ti^（4＋） ions which promoted changes in the density of states and gap band of TiCh.The dopant insertion resulted in a better structural stability of the nanocrystals that enhanced their charge transference and photocatalytic efficiency.展开更多
Using polystyrene （PSt） particles as template, PSt/TiO2 composite particles with AgCl incorporation were prepared through hydrolysis of tetrabutyl titanate in the presence of AgNO3 and NaCl. AgCl doped TiO2 hollow p...Using polystyrene （PSt） particles as template, PSt/TiO2 composite particles with AgCl incorporation were prepared through hydrolysis of tetrabutyl titanate in the presence of AgNO3 and NaCl. AgCl doped TiO2 hollow particles were successfully prepared with the PSt/TiO2 composite microspheres pretreated at 180 ℃ followed by calcination. The morphology of PSt/TiO2 particles and the crystal structures of the AgCl doped TiO2 hollow particles were characterized. The photocatalytic activity of the doped TiO2 hollow particles in degradation of Rhodamine B was tested under UV and visible lights and compared to that with Ag doped TiO2 particles. The results showed that TiO2 hollow particles, either doped with Ag or AgCl, demonstrated higher photocatalytic activity than the pure TiO2 particles. This enhancement in photocatalytic activity was more significant with AgCl doped TiO2 than that with Ag doped, and more distinct when the degradation was done under visible light than that under UV light.展开更多
A series of poly(phenylenevinylene) (PPV)/titanium oxide (TiO_2)nanocomposites with different contents of TiO_2 nanoparticles were prepared from mixtures of PPVprecursor and titanium butoxide ethanol solution in a sol...A series of poly(phenylenevinylene) (PPV)/titanium oxide (TiO_2)nanocomposites with different contents of TiO_2 nanoparticles were prepared from mixtures of PPVprecursor and titanium butoxide ethanol solution in a sol- gel process. TEM images showed theformation of the connected network of TiO_2 nanoparticles with a higher content of TiO_2, whichresulted in the titanium butoxide hydrolyzed to form Ti organic compound. Meanwhile, the conjugationof PPV polymer chains can be interrupted by the TiO_2 network structure. The PL spectra revealedthat the emitted light of the PPV/TiO_2 nanocomposites blue shifted without fine structure and thePL intensity enhanced when the TiO_2 network formed. In the lifetime spectroscopy of positronannihilation, the structural properties of the PPV dominated the character of the nanocomposites, inwhich the formation of the omicron -Ps was presented in free volume polymer, when the content ofTiO_2 was below 10 percent. Further increasing the content of TiO_2 nanoparticle introduced muchmore vacancies, vacancy clusters and grain boundaries at their interfaces, which led to thecorresponding lifetime and intensity close to that of the nano- TiO_2 bulk materials. With the TiO_2content of 50 percent of long lifetime. These phenomena suggested that the optical and structuralproperties of the PPV/TiO_2 nanocomposites are dependent on the interfacial structure between PPVand TiO_2 nanoparticles.展开更多
Graphite/TiO2 composite particles were obtained by sol-gel technique in this paper. The structure and characteristic of the composite particles are analyzed by XRD, SEM and TG-DTA. The electrorheological properties of...Graphite/TiO2 composite particles were obtained by sol-gel technique in this paper. The structure and characteristic of the composite particles are analyzed by XRD, SEM and TG-DTA. The electrorheological properties of the ER fluid containing the particles were measured by a Couette-type rheometer under shear rates of 1-136 s-1 and AC electric fields of 0-3 kV/mm. The experimental results show that the leaking current density of the ER fluid is higher than that of pure titanium dioxide particles dispersed in damping oil. The shear yield stress of the ER fluid increases with increasing electric field and exhibits a typical Bingham flow behavior. The suspension demonstrates an excellent ER performance (τ/τo=1200) compared with conventional ER fluids (τ/τ0 ≤500). The sedimentation of the ER fluid is improved obviously due to the coating effect of the particles.展开更多
The microporous nanocry'sta1line TiO2 electrode with large surface roughness factor hasbeen prepared on a conducting glass support. Modification of the TiO2 electrode by in situ preparingquantum sized RuS2 particl...The microporous nanocry'sta1line TiO2 electrode with large surface roughness factor hasbeen prepared on a conducting glass support. Modification of the TiO2 electrode by in situ preparingquantum sized RuS2 particles on the surface of TiO2 electrode extends the optical absorptionspectrum and photocurrent action specmim into visible region. In addition, compared with RuS2 bulknlaterials- a blue shifi in both absorption spectrum and photocurrent action speCtrum of RuS2rriO2elcctrode is obserived and explained in terms of quantum sized effect.展开更多
The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry w...The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.展开更多
Preparing multifunctional coatings with both anti-corrosion and anti-biofouling properties is crucial.Copper has been in the spotlight as an effective biocide,especially in the recent past concerning its impact on cau...Preparing multifunctional coatings with both anti-corrosion and anti-biofouling properties is crucial.Copper has been in the spotlight as an effective biocide,especially in the recent past concerning its impact on causing environmental hazards.Reducing the amount used and increasing its efficiency have become the focus of researchers.The hybridization of titanium dioxide nanoparticles(NPs)with copper metal-organic frameworks(MOFs)can significantly improve antimicrobial performance due to its photocatalytic properties.Composites(TiO_(2)-Cu-BTC)of titanium dioxide nanoparticles and copper 1,3,5-benzenetricarboxylate acid(Cu-BTC),obtained by three up-sampling methods,namely hydrothermal,mechanical stirring,and in-situ growth,were doped into epoxy resin(TiO_(2)-Cu-BTC/EP)to enhance its anticorrosion and antifouling properties.The loaded forms were determined by field emission scanning electron microscopy and confirmed using Fourier infrared spectroscopy and X-ray diffraction spectroscopy.The lethality of the composite coating against Escherichia coli(E.coli)increased by 12%after 3 h of exposure to light,and the impedance value increased by 1×1010Ω.The efficiency of the coating was greatly improved.展开更多
Although the strengthening and grain refinement effects of TiB_(2) particles on aluminum alloys have been extensively studied,their influence on casting behavior remains relatively underexplored.In this study,the infl...Although the strengthening and grain refinement effects of TiB_(2) particles on aluminum alloys have been extensively studied,their influence on casting behavior remains relatively underexplored.In this study,the influence of different addition amounts of submicron TiB_(2) particles on the microstructure,casting performance,and mechanical properties of an Al-Cu(ZL205A)alloy was systematically investigated.The introduction of TiB_(2) particles leads to significant grain refinement,transforming the microstructure from coarse grains to fine equiaxed grains by providing additional nucleation sites and inhibiting grain growth.SEM and TEM analyses reveal that the added submicron TiB_(2) particles exhibit minimal effect on the distribution of intermetallic phases or precipitates.Casting performance,as evaluated by spiral fluidity and hot tearing tests,shows notable improvements with TiB_(2) additions.At a TiB_(2) content of 3wt.%,the fluidity length increases by 20%,and the hot tearing susceptibility coefficient decreases by 29%.These enhancements are mainly due to the refined grain structure and the formation of interdendritic bridging in TiB_(2)-reinforced alloys.However,the overall enahncement in casting properties shows little variation across the TiB_(2) additions from 0.2wt.% to 3wt.%.Mechanical testing shows that the highest hardness and strength are achieved with a 1wt.%addition of TiB_(2) particles,primarily attributed to refined grain size and reinforcement of the aluminum matrix.Based on these findings,a TiB_(2) particle content of 1wt.%is recommended for optimizing both the casting performance and mechanical properties of the ZL205A alloy.展开更多
The unique properties of TiO_(2)-sulfur(TiO_(2)-S)modified graphene nanocomposite electrode(GPE/TiO_(2)-S)in the electrochemical sensing of formaldehyde compound has been evaluated.We prepared TiO_(2)-S by hydrotherma...The unique properties of TiO_(2)-sulfur(TiO_(2)-S)modified graphene nanocomposite electrode(GPE/TiO_(2)-S)in the electrochemical sensing of formaldehyde compound has been evaluated.We prepared TiO_(2)-S by hydrothermal method and modified the graphene nanocomposite electrode by applying electrochemical cyclic voltammetry(CV)approach.The TiO_(2)-S nanocomposite was characterized by X-ray diffraction(XRD),while the GPE/TiO_(2)-S was examined by scanning electron microscopy(FESEM)and X-Ray fluorosense(XRF)techniques.TiO_(2)-S has a grain size of 19.32 nm.The surface morphology of the GPE/TiO_(2)-S nanocomposite shows a good,intact,and tightly porous structure with TiO_(2)-S covers the graphene surface.The content of optimized GPE/TiO_(2)-S electrodes is 41.5%of graphene,37.8%of TiO_(2),and 12.4%of sulfur that was prepared by mixing 1 g of TiO_(2)-S with 0.5 g of graphene and 0.3 mL paraffin.The GPE/TiO_(2)-S electrode produces a high anodic current(I_(pa))of 800μA and a high cathodic current(I_(pc))of-600μA at a scan rate of 0.1 V·s^(-1)using an electrolyte0.01 mol·L^(-1)K_3[Fe(CN)_6]solution containing 150 mg·L^(-1)formaldehyde.The limit of detection can reach as low as 9.7 mg·L^(-1)with stability with Horwitz ratio value as low as 0.397.The composite electrode also exhibits excellent slectivity properties by showing clear formaldehyde sugnal in the presence of high concentration of interfering agent.GPE/TiO_(2)-S electrode should find potential application of formaldehyde detection in food industries.展开更多
Chemical hydrogen storage technology is crucial for the widespread use of hydrogen,with significant research progress being made in hydrazine hydrate(N_(2)H_(4)·H_(2)O).However,the efficient decomposition of N_(2...Chemical hydrogen storage technology is crucial for the widespread use of hydrogen,with significant research progress being made in hydrazine hydrate(N_(2)H_(4)·H_(2)O).However,the efficient decomposition of N_(2)H_(4)·H_(2)O remains a major challenge,hindered by dynamic constraints.To address this,we prepared NiPt nanoparticles deposited onto urchin-like TiO_(2)(u-TiO_(2))using the impregnation-reduction method,resulting in the NiPt/u-TiO_(2)catalyst.Remarkably,the Ni0.5Pt0.5/u-TiO_(2)catalyst demonstrated 100%H_(2)selectivity,ultrahigh catalytic activity and remarkable durability for N_(2)H_(4)·H_(2)O dehydrogenation,with a turnover frequency(TOF)of115.8 min^(-1),surpassing that of the corresponding NiPt/commercial TiO_(2)(c-TiO_(2)).Characterization and experimental findings suggest that the remarkable activity may originate from the unique urchin-like structure of the catalyst,along with the synergistic interaction between NiPt metals and the support.This research opens new avenues for designing nanomaterials with morphology advantages for hydrogen evolution reaction.展开更多
Pure TiO_(2)and copper-modified titania(Cu/TiO_(2))nanoparticles were synthesized through sol gel combined with the pyrolysis method for the removal of Congo red(CR)in wastewater treatment.Surface morphology and struc...Pure TiO_(2)and copper-modified titania(Cu/TiO_(2))nanoparticles were synthesized through sol gel combined with the pyrolysis method for the removal of Congo red(CR)in wastewater treatment.Surface morphology and structural evaluation utilized XRD,TEM,Raman,FTIR and BET techniques.Cu/TiO_(2)showed rich defects and a higher specific surface area than that of TiO_(2).The 1Cu/TiO_(2)(molar ratio Cu/TiO_(2)of 1/100)showed the best performance to adsorption of CR solution at different reaction conditions(contact duration,CR concentration,adsorbent dose,temperature,and initial pH).Adsorption kinetics and equilibrium isotherms were well-described with a pseudo-second-order kinetics and Freundlich model,respectively.The negative ΔG indicates stable adsorption of CR on the Cu/TiO_(2)surface.The adsorption efficiency only decreases by 6%after 5 cycles of adsorption regeneration.The successful synthesis of Cu/TiO_(2)offers a new possibility to address the problems related to CR dye from aqueous solutions.展开更多
Water electrolysis to produce hydrogen has broad prospects due to its pollution-free feature,yet its electrolysis efficiency is limited by the slow kinetics of the anodic oxygen evolution reaction(OER).In this study,w...Water electrolysis to produce hydrogen has broad prospects due to its pollution-free feature,yet its electrolysis efficiency is limited by the slow kinetics of the anodic oxygen evolution reaction(OER).In this study,we develop a synergistic catalyst which integrates MXene/TiO_(2)-supported Ru nanoparticles and oxygen-coordinated Co single atoms(RuCo-MXene/TiO_(2))for efficient OER.This double-tuned structure enables both high-density active sites and precise microenvironment control.Moreover,the interaction between metals during annealing process provides the generation of metallic-bonded Ru-Co pairs between Ru nanoparticles and Co single atoms,facilitating Ru nanoparticles-to-support charge transfer,resulting in optimized electronic properties of the catalyst.As expected,the as-synthesized RuCo-MXene/TiO_(2) catalyst at 10 mA·cm^(-2) current density exhibits 208 mV low overportential and a longterm stability of up to 500 h,which is superior to Ru-MXene/TiO_(2) and Co-MXene/TiO_(2).This work provides a promising strategy for designing efficient and stable electrocatalysts for renewable energy applications.展开更多
The instantaneous desulfurization of CaO-Al_(2)O_(3)-SiO_(2)slag particles in the molten steel was in situ observed using a high-temperature confocal scanning laser microscope.The desulfurization effect of CaO-Al_(2)O...The instantaneous desulfurization of CaO-Al_(2)O_(3)-SiO_(2)slag particles in the molten steel was in situ observed using a high-temperature confocal scanning laser microscope.The desulfurization effect of CaO-Al_(2)O_(3)-SiO_(2)slags with different compositions was discussed.The influence of CaO/Al_(2)O_(3)and CaO/SiO_(2)on the desulfurization effect was analyzed.It was shown that in the liquid phase range,the higher CaO/SiO_(2)and CaO/Al_(2)O_(3)can significantly improve the desulfurization effect of the slag.A dimensionless desulfurization index Sindex was introduced to evaluate the desulfurization ability of CaO-Al_(2)O_(3)-SiO_(2)slags quantitatively.The Sindex values of CaO-Al_(2)O_(3)-SiO_(2)with different compositions at 1550°C were calculated.It was suggested to use(65%-75%)CaO-(0-20%)SiO_(2)-(20%-40%)Al_(2)O_(3)slags to improve the molten steel desulfurization.展开更多
Silicon(Si)is an inevitable impurity element in the AZ31 alloy.In this study,the Si impurity was detected mainly as fine Mg_(2)Si particles dispersed widely within the central region of the Mg_(17)Al_(12) phase.During...Silicon(Si)is an inevitable impurity element in the AZ31 alloy.In this study,the Si impurity was detected mainly as fine Mg_(2)Si particles dispersed widely within the central region of the Mg_(17)Al_(12) phase.During the solidification process,the Mg_(2)Si particle precipitates at about 565℃,before the Mg_(17)Al_(12) phase of 186℃,potentially acting as the heterogeneous nucleation core for the Mg_(17)Al_(12) phase.The orientation relationship between Mg_(2)Si and Mg_(17)Al_(12) was investigated using the Edge-to-Edge matching model(E2EM)calculations,which showed a misfit of only 0.1%.This low misfit suggests that Mg_(2)Si can serve as a heterogeneous nucleation site for Mg_(17)Al_(12).The surface and interface structures of Mg_(2)Si(220)and Mg_(17)Al_(12)(332)were constructed,and then investigated through the first-principles calculation.The theoretical results indicate that Mg and Al are easily adsorbed on the surface of Mg_(2)Si,with Al showing higher adsorption energy than Mg.Furthermore,the interface between Mg_(2)Si and Mg_(17)Al_(12) exhibits favorable thermodynamic stability.Combined with experiments and theoretical calculations,it is confirmed that the Mg_(2)Si particles,formed due to the Si impurity,provide effective heterogeneous nucleation sites for the Mg_(17)Al_(12) phase.展开更多
Both Ti foil and porous Ti were anodized in 0.5%HF and in ethylene glycol electrolyte containing 0.5%NH4F(mass fraction) separately. The results show that TiO2 nanotubes can be formed on Ti foil by both processes, whe...Both Ti foil and porous Ti were anodized in 0.5%HF and in ethylene glycol electrolyte containing 0.5%NH4F(mass fraction) separately. The results show that TiO2 nanotubes can be formed on Ti foil by both processes, whereas TiO2 nanotubes can be formed on porous Ti only in the second process. The overhigh current density led to the failure of the formation nanotubes on porous Ti in 0.5%HF electrolyte. TiO2 nanotubes were characterized by SEM and XRD. TiO2 nanotubes on porous Ti were thinner than those on Ti foil. Anatase was formed when TiO2 nanotubes were annealed at 400 °C and fully turned into rutile at 700 °C. To obtain good photodegradation, the optimal heat treatment temperature of TiO2 nanotubes was 450 °C. The porosity of the substrates influenced photodegradation properties. TiO2 nanotubes on porous Ti with 60% porosity had the best photodegradation.展开更多
文摘The surface of Titanium Hydride (TiH 2) is coated by Nano Titanium Dioxide (TiO 2) particles prepared in both of methods of hydrolysis reaction of Ti(OC 4H 9) 4 and base precipitation reaction of Ti(SO 4) 2. TiH 2 coated with nano TiO 2 particles, in which there is an oxidation film on its surface, shown in the experiments, will obviously achieve good effects on releasing hydrogen slowly in high temperature. There are different structures and properties of TiH 2 coated by nano TiO 2 particles prepared in different ways in high temperature, which can influence on releasing hydrogen.
文摘The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6-12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.
文摘The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.
基金National Key Technology R&D Program of China (2008BAE60B06)Beijing Municipal Science & Technology Commission (Z080003032208015)
文摘Barite/TiO2 composite particle (B/TCP) was prepared by coating TiO2 on the surfaces of barite particles through mechano-chemical method. The preparation parameters and pigment properties of B/TCP as well as the interaction mechanism between barite and TiO2 were studied. The results indicated that the mechanical co-grinding process and the proportion of TiO2 affected the properties of B/TCP significantly. B/TCP prepared under optimal conditions was similar to TiO2 in pigment properties. It was mainly the strong electrostatic attraction between barite and TiO2 in water that combined them firmly and then formed B/TCP.
基金supported by Consejo Nacional de Ciencia yTecnologia or National Council of Science and Technology(CONACYT,175925)
文摘Doped and undoped TiCh nanoparticles were prepared by Stober method and thermally treated at 600 ℃.The effect of Nd^（3＋） ion on the structure and micro structure of anatase-phase TiCh nanocrystals was studied by Rietveld refinement method using X-ray powder diffraction data.Bond lengths,bond angles,and edges distances were analyzed.The phase formation was confirmed by high-resolution transmission electron microscopy.The adjustment of Ti-0 bond length induced by the addition of Nd^（3＋） ions,reduced the octahedral distortion and altered the octahedral array in the anatase-phase TiCh nanocrystal.The changes of structure and microstructure were mainly observed for TiCh nanoparticles doped with 0.1 at.%of Nd^（3＋） ions and attributed to the cationic substitution of Ti^（4＋） ions which promoted changes in the density of states and gap band of TiCh.The dopant insertion resulted in a better structural stability of the nanocrystals that enhanced their charge transference and photocatalytic efficiency.
文摘Using polystyrene （PSt） particles as template, PSt/TiO2 composite particles with AgCl incorporation were prepared through hydrolysis of tetrabutyl titanate in the presence of AgNO3 and NaCl. AgCl doped TiO2 hollow particles were successfully prepared with the PSt/TiO2 composite microspheres pretreated at 180 ℃ followed by calcination. The morphology of PSt/TiO2 particles and the crystal structures of the AgCl doped TiO2 hollow particles were characterized. The photocatalytic activity of the doped TiO2 hollow particles in degradation of Rhodamine B was tested under UV and visible lights and compared to that with Ag doped TiO2 particles. The results showed that TiO2 hollow particles, either doped with Ag or AgCl, demonstrated higher photocatalytic activity than the pure TiO2 particles. This enhancement in photocatalytic activity was more significant with AgCl doped TiO2 than that with Ag doped, and more distinct when the degradation was done under visible light than that under UV light.
文摘A series of poly(phenylenevinylene) (PPV)/titanium oxide (TiO_2)nanocomposites with different contents of TiO_2 nanoparticles were prepared from mixtures of PPVprecursor and titanium butoxide ethanol solution in a sol- gel process. TEM images showed theformation of the connected network of TiO_2 nanoparticles with a higher content of TiO_2, whichresulted in the titanium butoxide hydrolyzed to form Ti organic compound. Meanwhile, the conjugationof PPV polymer chains can be interrupted by the TiO_2 network structure. The PL spectra revealedthat the emitted light of the PPV/TiO_2 nanocomposites blue shifted without fine structure and thePL intensity enhanced when the TiO_2 network formed. In the lifetime spectroscopy of positronannihilation, the structural properties of the PPV dominated the character of the nanocomposites, inwhich the formation of the omicron -Ps was presented in free volume polymer, when the content ofTiO_2 was below 10 percent. Further increasing the content of TiO_2 nanoparticle introduced muchmore vacancies, vacancy clusters and grain boundaries at their interfaces, which led to thecorresponding lifetime and intensity close to that of the nano- TiO_2 bulk materials. With the TiO_2content of 50 percent of long lifetime. These phenomena suggested that the optical and structuralproperties of the PPV/TiO_2 nanocomposites are dependent on the interfacial structure between PPVand TiO_2 nanoparticles.
基金The authors are thankful to the support of the National Natural Science Foundation of China(Grant No.50135030).
文摘Graphite/TiO2 composite particles were obtained by sol-gel technique in this paper. The structure and characteristic of the composite particles are analyzed by XRD, SEM and TG-DTA. The electrorheological properties of the ER fluid containing the particles were measured by a Couette-type rheometer under shear rates of 1-136 s-1 and AC electric fields of 0-3 kV/mm. The experimental results show that the leaking current density of the ER fluid is higher than that of pure titanium dioxide particles dispersed in damping oil. The shear yield stress of the ER fluid increases with increasing electric field and exhibits a typical Bingham flow behavior. The suspension demonstrates an excellent ER performance (τ/τo=1200) compared with conventional ER fluids (τ/τ0 ≤500). The sedimentation of the ER fluid is improved obviously due to the coating effect of the particles.
文摘The microporous nanocry'sta1line TiO2 electrode with large surface roughness factor hasbeen prepared on a conducting glass support. Modification of the TiO2 electrode by in situ preparingquantum sized RuS2 particles on the surface of TiO2 electrode extends the optical absorptionspectrum and photocurrent action specmim into visible region. In addition, compared with RuS2 bulknlaterials- a blue shifi in both absorption spectrum and photocurrent action speCtrum of RuS2rriO2elcctrode is obserived and explained in terms of quantum sized effect.
文摘The homogeneous electrocatalytic oxidation of hydrazine（HZ） has been studied by indigocarmine（IND） as a mediator at the surface of TiO_2 nanoparticles modified carbon paste electrode（TNMCPE）.Cyclic voltammetry was used to study the electrochemical behavior of IND at different scan rates.The voltammetric response of the modified electrode was linear against the concentration of HZ in the ranges of 3.0×l0^（-8）-7.0×10~6 mol/L with differential pulse voltammetry method.The detection limit（3σ） was determined as 27.3 nmol/L.To evaluate the applicability of the proposed method to real samples,the modified CPE was applied to the determination of HZ in water samples.
基金Project(52073311) supported by the National Natural Science Foundation of ChinaProject(2023A0505010011) supported by the Guangdong-Hong Kong-Macao Joint Innovation Field Research Foundation,ChinaProject(2021A1515012281) supported by the Guangdong Basic and Applied Basic Research Foundation,China。
文摘Preparing multifunctional coatings with both anti-corrosion and anti-biofouling properties is crucial.Copper has been in the spotlight as an effective biocide,especially in the recent past concerning its impact on causing environmental hazards.Reducing the amount used and increasing its efficiency have become the focus of researchers.The hybridization of titanium dioxide nanoparticles(NPs)with copper metal-organic frameworks(MOFs)can significantly improve antimicrobial performance due to its photocatalytic properties.Composites(TiO_(2)-Cu-BTC)of titanium dioxide nanoparticles and copper 1,3,5-benzenetricarboxylate acid(Cu-BTC),obtained by three up-sampling methods,namely hydrothermal,mechanical stirring,and in-situ growth,were doped into epoxy resin(TiO_(2)-Cu-BTC/EP)to enhance its anticorrosion and antifouling properties.The loaded forms were determined by field emission scanning electron microscopy and confirmed using Fourier infrared spectroscopy and X-ray diffraction spectroscopy.The lethality of the composite coating against Escherichia coli(E.coli)increased by 12%after 3 h of exposure to light,and the impedance value increased by 1×1010Ω.The efficiency of the coating was greatly improved.
文摘Although the strengthening and grain refinement effects of TiB_(2) particles on aluminum alloys have been extensively studied,their influence on casting behavior remains relatively underexplored.In this study,the influence of different addition amounts of submicron TiB_(2) particles on the microstructure,casting performance,and mechanical properties of an Al-Cu(ZL205A)alloy was systematically investigated.The introduction of TiB_(2) particles leads to significant grain refinement,transforming the microstructure from coarse grains to fine equiaxed grains by providing additional nucleation sites and inhibiting grain growth.SEM and TEM analyses reveal that the added submicron TiB_(2) particles exhibit minimal effect on the distribution of intermetallic phases or precipitates.Casting performance,as evaluated by spiral fluidity and hot tearing tests,shows notable improvements with TiB_(2) additions.At a TiB_(2) content of 3wt.%,the fluidity length increases by 20%,and the hot tearing susceptibility coefficient decreases by 29%.These enhancements are mainly due to the refined grain structure and the formation of interdendritic bridging in TiB_(2)-reinforced alloys.However,the overall enahncement in casting properties shows little variation across the TiB_(2) additions from 0.2wt.% to 3wt.%.Mechanical testing shows that the highest hardness and strength are achieved with a 1wt.%addition of TiB_(2) particles,primarily attributed to refined grain size and reinforcement of the aluminum matrix.Based on these findings,a TiB_(2) particle content of 1wt.%is recommended for optimizing both the casting performance and mechanical properties of the ZL205A alloy.
基金the financial support from the Ministry of Education,Culture,Research and Technology of the Republic of Indonesia under the Applied Research award(DIPA023.17.1.690523/2023)the World Class Professor award grant 2023。
文摘The unique properties of TiO_(2)-sulfur(TiO_(2)-S)modified graphene nanocomposite electrode(GPE/TiO_(2)-S)in the electrochemical sensing of formaldehyde compound has been evaluated.We prepared TiO_(2)-S by hydrothermal method and modified the graphene nanocomposite electrode by applying electrochemical cyclic voltammetry(CV)approach.The TiO_(2)-S nanocomposite was characterized by X-ray diffraction(XRD),while the GPE/TiO_(2)-S was examined by scanning electron microscopy(FESEM)and X-Ray fluorosense(XRF)techniques.TiO_(2)-S has a grain size of 19.32 nm.The surface morphology of the GPE/TiO_(2)-S nanocomposite shows a good,intact,and tightly porous structure with TiO_(2)-S covers the graphene surface.The content of optimized GPE/TiO_(2)-S electrodes is 41.5%of graphene,37.8%of TiO_(2),and 12.4%of sulfur that was prepared by mixing 1 g of TiO_(2)-S with 0.5 g of graphene and 0.3 mL paraffin.The GPE/TiO_(2)-S electrode produces a high anodic current(I_(pa))of 800μA and a high cathodic current(I_(pc))of-600μA at a scan rate of 0.1 V·s^(-1)using an electrolyte0.01 mol·L^(-1)K_3[Fe(CN)_6]solution containing 150 mg·L^(-1)formaldehyde.The limit of detection can reach as low as 9.7 mg·L^(-1)with stability with Horwitz ratio value as low as 0.397.The composite electrode also exhibits excellent slectivity properties by showing clear formaldehyde sugnal in the presence of high concentration of interfering agent.GPE/TiO_(2)-S electrode should find potential application of formaldehyde detection in food industries.
基金financially supported by the National Natural Science Foundation of China(Nos.22478001,U22A20408 and 22108238)the Excellent Young Scholars Program of Natural Science Foundation Anhui Province(No.2408085Y005)+3 种基金the Excellent Youth Scholars Program of Higher Education Institutions of Anhui Province(No.2024AH030008)the Open Fund of Shanghai Jiao Tong University Shaoxing Research Institute(No.JDSX2023014)the State Key Laboratory of Clean Energy Utilization(No.ZJUCEU2024017)the Outstanding Scientific Research and Innovation Team Program of Higher Education Institutions of Anhui Province(No.2023AH010015)
文摘Chemical hydrogen storage technology is crucial for the widespread use of hydrogen,with significant research progress being made in hydrazine hydrate(N_(2)H_(4)·H_(2)O).However,the efficient decomposition of N_(2)H_(4)·H_(2)O remains a major challenge,hindered by dynamic constraints.To address this,we prepared NiPt nanoparticles deposited onto urchin-like TiO_(2)(u-TiO_(2))using the impregnation-reduction method,resulting in the NiPt/u-TiO_(2)catalyst.Remarkably,the Ni0.5Pt0.5/u-TiO_(2)catalyst demonstrated 100%H_(2)selectivity,ultrahigh catalytic activity and remarkable durability for N_(2)H_(4)·H_(2)O dehydrogenation,with a turnover frequency(TOF)of115.8 min^(-1),surpassing that of the corresponding NiPt/commercial TiO_(2)(c-TiO_(2)).Characterization and experimental findings suggest that the remarkable activity may originate from the unique urchin-like structure of the catalyst,along with the synergistic interaction between NiPt metals and the support.This research opens new avenues for designing nanomaterials with morphology advantages for hydrogen evolution reaction.
基金supported by the Inner Mongolia Natural Science Foundation(2024QN02011)basic scientific research business expense project of colleges and universities directly under Inner Mongolia(2023QNJS131 and 2024QNJS127)Science and Technology Plan Program of Inner Mongolia Autonomous Region(2023YFDZ0031).
文摘Pure TiO_(2)and copper-modified titania(Cu/TiO_(2))nanoparticles were synthesized through sol gel combined with the pyrolysis method for the removal of Congo red(CR)in wastewater treatment.Surface morphology and structural evaluation utilized XRD,TEM,Raman,FTIR and BET techniques.Cu/TiO_(2)showed rich defects and a higher specific surface area than that of TiO_(2).The 1Cu/TiO_(2)(molar ratio Cu/TiO_(2)of 1/100)showed the best performance to adsorption of CR solution at different reaction conditions(contact duration,CR concentration,adsorbent dose,temperature,and initial pH).Adsorption kinetics and equilibrium isotherms were well-described with a pseudo-second-order kinetics and Freundlich model,respectively.The negative ΔG indicates stable adsorption of CR on the Cu/TiO_(2)surface.The adsorption efficiency only decreases by 6%after 5 cycles of adsorption regeneration.The successful synthesis of Cu/TiO_(2)offers a new possibility to address the problems related to CR dye from aqueous solutions.
基金supported by the National Natural Science Foundation of China(No.22568017)Guizhou Provincial Science and Technology Projects(No.ZKZD2023004)+2 种基金Key Laboratory of Carbon-based Energy Molecular Chemical Utilization Technology in Guizhou Province(No.2023008)One Hundred Person Project of Guizhou Province(No.GCC 2023013)Scientific and Technological Innovation Talents Team Project of Guizhou Province(No.CXTD2023029).
文摘Water electrolysis to produce hydrogen has broad prospects due to its pollution-free feature,yet its electrolysis efficiency is limited by the slow kinetics of the anodic oxygen evolution reaction(OER).In this study,we develop a synergistic catalyst which integrates MXene/TiO_(2)-supported Ru nanoparticles and oxygen-coordinated Co single atoms(RuCo-MXene/TiO_(2))for efficient OER.This double-tuned structure enables both high-density active sites and precise microenvironment control.Moreover,the interaction between metals during annealing process provides the generation of metallic-bonded Ru-Co pairs between Ru nanoparticles and Co single atoms,facilitating Ru nanoparticles-to-support charge transfer,resulting in optimized electronic properties of the catalyst.As expected,the as-synthesized RuCo-MXene/TiO_(2) catalyst at 10 mA·cm^(-2) current density exhibits 208 mV low overportential and a longterm stability of up to 500 h,which is superior to Ru-MXene/TiO_(2) and Co-MXene/TiO_(2).This work provides a promising strategy for designing efficient and stable electrocatalysts for renewable energy applications.
基金support from the National Key R&D Program(No.2023YFB3709901)the National Natural Science Foundation of China(Grant No.U22A20171)China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202315).
文摘The instantaneous desulfurization of CaO-Al_(2)O_(3)-SiO_(2)slag particles in the molten steel was in situ observed using a high-temperature confocal scanning laser microscope.The desulfurization effect of CaO-Al_(2)O_(3)-SiO_(2)slags with different compositions was discussed.The influence of CaO/Al_(2)O_(3)and CaO/SiO_(2)on the desulfurization effect was analyzed.It was shown that in the liquid phase range,the higher CaO/SiO_(2)and CaO/Al_(2)O_(3)can significantly improve the desulfurization effect of the slag.A dimensionless desulfurization index Sindex was introduced to evaluate the desulfurization ability of CaO-Al_(2)O_(3)-SiO_(2)slags quantitatively.The Sindex values of CaO-Al_(2)O_(3)-SiO_(2)with different compositions at 1550°C were calculated.It was suggested to use(65%-75%)CaO-(0-20%)SiO_(2)-(20%-40%)Al_(2)O_(3)slags to improve the molten steel desulfurization.
基金supported by the National Natural Science Foundation of China(Nos.51871100 and 12074126).
文摘Silicon(Si)is an inevitable impurity element in the AZ31 alloy.In this study,the Si impurity was detected mainly as fine Mg_(2)Si particles dispersed widely within the central region of the Mg_(17)Al_(12) phase.During the solidification process,the Mg_(2)Si particle precipitates at about 565℃,before the Mg_(17)Al_(12) phase of 186℃,potentially acting as the heterogeneous nucleation core for the Mg_(17)Al_(12) phase.The orientation relationship between Mg_(2)Si and Mg_(17)Al_(12) was investigated using the Edge-to-Edge matching model(E2EM)calculations,which showed a misfit of only 0.1%.This low misfit suggests that Mg_(2)Si can serve as a heterogeneous nucleation site for Mg_(17)Al_(12).The surface and interface structures of Mg_(2)Si(220)and Mg_(17)Al_(12)(332)were constructed,and then investigated through the first-principles calculation.The theoretical results indicate that Mg and Al are easily adsorbed on the surface of Mg_(2)Si,with Al showing higher adsorption energy than Mg.Furthermore,the interface between Mg_(2)Si and Mg_(17)Al_(12) exhibits favorable thermodynamic stability.Combined with experiments and theoretical calculations,it is confirmed that the Mg_(2)Si particles,formed due to the Si impurity,provide effective heterogeneous nucleation sites for the Mg_(17)Al_(12) phase.
基金Project(1254G024)supported by the Young Core Instructor Foundation from Heilongjiang Educational Committee,ChinaProject(2012RFQXS113)supported by Scientific and Technological Innovation Talents of Harbin,China
文摘Both Ti foil and porous Ti were anodized in 0.5%HF and in ethylene glycol electrolyte containing 0.5%NH4F(mass fraction) separately. The results show that TiO2 nanotubes can be formed on Ti foil by both processes, whereas TiO2 nanotubes can be formed on porous Ti only in the second process. The overhigh current density led to the failure of the formation nanotubes on porous Ti in 0.5%HF electrolyte. TiO2 nanotubes were characterized by SEM and XRD. TiO2 nanotubes on porous Ti were thinner than those on Ti foil. Anatase was formed when TiO2 nanotubes were annealed at 400 °C and fully turned into rutile at 700 °C. To obtain good photodegradation, the optimal heat treatment temperature of TiO2 nanotubes was 450 °C. The porosity of the substrates influenced photodegradation properties. TiO2 nanotubes on porous Ti with 60% porosity had the best photodegradation.
