The use of titanium dioxide nanoparticles (nTiO<sub>2</sub>) is gaining interest in agriculture because of their impact on many aspects of plant growth. The present study examines the effects of nTiO<su...The use of titanium dioxide nanoparticles (nTiO<sub>2</sub>) is gaining interest in agriculture because of their impact on many aspects of plant growth. The present study examines the effects of nTiO<sub>2</sub> (5 nm and 10 nm) applied to seeds and the seedlings as a foliar application on various aspects of growth characteristics and biomass accumulation in lettuce (Lactuca sativa, cv. Grand Rapids). Application of 10 nm nTiO<sub>2</sub> to seeds through imbibition resulted in a significant reduction in shoot biomass accumulation while 5 nm nTiO<sub>2</sub> did not affect the biomass accumulation in lettuce. The application of 10 nm nTiO<sub>2</sub> reduced the fresh shoot biomass accumulation by about 18% compared to the control plants. Other growth characteristics such as shoot dry biomass, root fresh and dry biomass, plant height, and leaf area were not affected by the application of both 5 nm and 10 nm nTiO<sub>2</sub>. In addition, foliar application of these nanoparticles to the lettuce seedlings did not have a significant effect on most of the growth parameters examined, and the increasing concentration ranging from 5 nm/L to 400 mg/L did not produce a consistent response in lettuce. Thus, nTiO<sub>2</sub> application to lettuce seeds had a notable negative impact on shoot growth while foliar application did not have a significant effect on many plant growth characteristics. However, foliar applications produced some symptoms of toxicity to the foliage in the form of necrotic or chlorotic patches on the leaves, which were more pronounced with increasing concentrations of both 5 nm and 10 nm nTiO<sub>2</sub>. However, these symptoms were apparent at a concentration as low as 50 mg/L of nTiO<sub>2</sub>. Thus, foliar application of nTiO<sub>2</sub> may not have a significant impact on many of the growth characteristics in lettuce, but it can result in foliar toxicity.展开更多
In this study,three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide(Mg Fe_2O_(4)-GM/TiO_(2)/rGO(MGTG))was successfully synthesized via green and hydrothermal-supported co-precipitation met...In this study,three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide(Mg Fe_2O_(4)-GM/TiO_(2)/rGO(MGTG))was successfully synthesized via green and hydrothermal-supported co-precipitation methods using the extract of Garcinia mangostana(G.mangostana)as a reducing agent.The characterization results indicate the successful formation of the nano/micro Mg Fe_(2)O_(4)(MFO)and TiO_(2) on the structure of the reduced graphene oxide(rGO),which can also act as efficient support,alleviating the agglomeration of the nano/micro MFO and TiO_(2).The synergic effects of the adsorption and photodegradation activity of the material were investigated according to the removal of crystal violet(CV)under ultraviolet light.The effects of catalyst dosage,CV concentration,and p H on the CV removal efficiency of the MGTG were also investigated.According to the results,the CV photodegradation of the MGTG-200 corresponded to the pseudo-first-order kinetic model.The reusability of the material after 10 cycles also showed a removal efficiency of 92%.This happened because the materials can easily be recollected using external magnets.In addition,according to the effects of different free radicals·O_(2)^(-),h^(+),and·OH on the photodegradation process,the photocatalysis mechanism of the MGTG was also thoroughly suggested.The antibacterial efficiency of the MGTG was also evaluated according to the inhibition of the Gram-positive bacteria strain Staphylococcus aureus(S.aureus).Concurrently,the antibacterial mechanism of the fabricated material was also proposed.These results confirm that the prepared material can be potentially employed in a wide range of applications,including wastewater treatment and antibacterial activity.展开更多
To meet the low-cost concept advocated by the sodium metal anode,this paper reports the use of a pulsed electrodeposition technology with ionic liquids as electrolytes to achieve uniform nanoplating of metallic magnes...To meet the low-cost concept advocated by the sodium metal anode,this paper reports the use of a pulsed electrodeposition technology with ionic liquids as electrolytes to achieve uniform nanoplating of metallic magnesium films at around 20 nm on spaced titanium dioxide(TiO_(2))nanotubes(STNA-Mg).First,the sodiophilic magnesium metal coating can effectively reduce the nucleation overpotential of sodium metal.Moreover,three-dimensional STNA can limit the volume expansion during sodium metal plating and stripping to achieve the ultrastable deposition and stripping of sodium metals with a high Coulombic efficiency of up to 99.5%and a small voltage polarization of 5 mV in symmetric Na||Na batteries.In addition,the comparative study of sodium metal deposition behavior of STNA-Mg and STNA-Cu prepared by the same route further confirmed the advantage of magnesium metal to guide sodium metal growth.Finally,the prepared STNA-Mg-Na metal anode and commercial sodium vanadium phosphate cathode were assembled into a full cell,delivering a discharge capacity of 110.2 mAh·g^(-1)with a retention rate of 95.6%after 110 cycles at 1C rate.展开更多
Extremely high-temperature and high-pressure requirement of Haber-Bosch process motivates the search for a sustainable ammonia synthesis approach under mild conditions.Photocatalytic technology is a potential solution...Extremely high-temperature and high-pressure requirement of Haber-Bosch process motivates the search for a sustainable ammonia synthesis approach under mild conditions.Photocatalytic technology is a potential solution to convert N2 to ammonia.However,the poor light absorption and low charge carrier separation efficiency in conventional semiconductors are bottlenecks for the application of this technology.Herein,a facile synthesis of anatase TiO_(2)nanosheets with an abundance of surface oxygen vacancies(TiO_(2)-OV)via the calcination treatment was reported.Photocatalytic experiments of the prepared anatase TiO_(2)samples showed that TiO_(2)-OV nanosheets exhibited remarkably increased ammonia yield for solar-driven N2 fixation in pure water,without adding any sacrificial agents.EPR,XPS,XRD,UV-Vis DRS,TEM,Raman,and PL techniques were employed to systematically explore the possible enhanced mechanism.Studies revealed that the introduced surface oxygen vacancies significantly extended the light absorption capability in the visible region,decreased the adsorption and activation barriers of inert N2,and improved the separation and transfer efficiency of the photogenerated electronhole pairs.Thus,a high rate of ammonia evolution in TiO_(2)-OV was realized.This work offers a promising and sustainable approach for the efficient artificial photosynthesis of ammonia.展开更多
Expanded bed adsorption (EBA) has been widely used in industrial downstream bioprocessing,Solid matrix is the principal pillar supporting the successful application of EBA.A novel spherical ceelulose-titanium dioxide ...Expanded bed adsorption (EBA) has been widely used in industrial downstream bioprocessing,Solid matrix is the principal pillar supporting the successful application of EBA.A novel spherical ceelulose-titanium dioxide composite matrix was prepared through the method of water-in-oil suspension thermal regeneration.Its typical physical properties were wet density 1.18g.cm^-3,,diameters in the range of 100-300μm ,porosity 85.5%,and water content 72.3%.Expansion characteristics and liquid mixing performance of the matrix in expanded bed were investigated using water and 10% (by mass )glycerol solution as mobile phases,The results indicate that the custom-assembled matrix has a stable flow hydrodynamics and exhibits the same degree of liquid-phase mixing or column efficiency as the commercially available Streamline adsorbent.展开更多
This study aims to prepare a composite polyurethane coating through a facile synthesis process. Titanium dioxide, which is a component of the prepared hydroxyl acrylic resin polyurethane varnish, was partially substit...This study aims to prepare a composite polyurethane coating through a facile synthesis process. Titanium dioxide, which is a component of the prepared hydroxyl acrylic resin polyurethane varnish, was partially substituted by wollastonite, and an optimal substitution ratio was obtained. Analyses based on scanning electron microscope, powder X-ray diffraction, and Raman scattering measurements demonstrated that the addition of wollastonite caused nearly no change in the basic structure of the coating. Coating with a substitution ratio of 25% showed high thermal stability, good cover effect, considerable moisture-proof and water resistance ability, great acidic and basic resistance, and improved performance and hardness in performance tests. Furthermore, the production cost was reduced significantly at this substitution ratio.展开更多
The aim of this study is to clarify the effect of different concentrations of titanium dioxide nanoparticles (Nps) on the properties of two types of heat polymerized acrylic resin. The tested parameters were flexural ...The aim of this study is to clarify the effect of different concentrations of titanium dioxide nanoparticles (Nps) on the properties of two types of heat polymerized acrylic resin. The tested parameters were flexural strength, impact strength, and microhardness. The two types of acrylic resin used in this study were conventional unmodified (Implacryl, Vertex) and high impact heat polymerized acrylic resin (Vertex-Dental, Netherlands). Both types of acrylic resin were modified by using 1% and 5% TiO<sub>2</sub> Nps powder. Specimen’s dimensions were prepared according to the American Dental Association Specification No. 12. Three types of specimens were prepared: 1) flexural strength specimens 50 mm × 10 (±0.2) mm × 3 (±0.2) mm, 2) impact strength test specimens 60 mm × 6.0 mm × 4.0 mm, 3) microhardnesss specimens 25 mm × 10 mm × 3 (±0.2) mm. For each test 6 groups were prepared (each group containing 5 samples). Thirty specimens were prepared in each of the three tests, amounting to a total number of 90 specimens. Mechanical properties such as flexural strength (FS), impact strength and microhardness of the above mentioned specimens were determined using universal testing machine, Izod pendulum impact testing machine and Vickers microhardness tester, respectively. ISO Specification No. 1567 was followed in microhardness test. The data was collected and statistically analyzed. Flexural strength considerably decreased by increasing TiO<sub>2</sub> concentration in both types of acrylic resin. Impact strength of the conventional acrylic resin modified by 1% of additives significantly increased. The microhardness is significantly increased by addition of 5% of TiO<sub>2</sub> Nps. The Incorporation of TiO<sub>2</sub> nanoparticles into acrylic resins can adversely affect its flexural strength. Meanwhile, the impact strength can be modified by small percentage of additives (abt. 1%). This effect is directly correlated with the concentration of nanoparticles. On the other hand, concentrations of TiO<sub>2</sub> Nps (abt. 5%) positively affect the microhardness of both types of acrylic resin used in the present study.</sub></sub></sub></sub></sub></sub></sub></sub></sub></sub>展开更多
The preparation of a new mineral composite material, calcium carbonate particles coated with titanium dioxide, was studied. The mechanism of the preparation process was proposed. The new mineral composite material was...The preparation of a new mineral composite material, calcium carbonate particles coated with titanium dioxide, was studied. The mechanism of the preparation process was proposed. The new mineral composite material was made by the mechanoehemieal method under the optimum condition that the mass ratio of calcium carbonate particles to titanium dioxide was 6.5:3.5. The mass ratios of two different types of titanium dioxide (anatase to rutile) and grinding media to grinded materials were 8:2 and 4:1 respectively, and the modified density was 60%. Under this condition, the new material was capable of forming after 120-min modification. The hiding power and oil absorption of this new material were 29.12 g/m^2 and 23.30%, respectively. The results show that the modification is based on surface hydroxylation. After coating with titanium dioxide, the hiding power of calcium carbonate can be improved greatly. The new mineral composite materials can be used as the substitute for titanium dioxide.展开更多
The adsorption potential of titanium dioxide (TiO2) nanoparticles for removing arsenic from drinking water was evaluated. Pure and iron-doped TiO2 particles are synthesized via sol-gel method. The synthesized TiO2 n...The adsorption potential of titanium dioxide (TiO2) nanoparticles for removing arsenic from drinking water was evaluated. Pure and iron-doped TiO2 particles are synthesized via sol-gel method. The synthesized TiO2 nanoparticles were then immobilized on ordinary sand for adsorption studies. Adsorption isotherms were conducted on the synthesized nanoparticles as well as the sand coated with TiO2 nanoparticles under varying conditions of air and light, namely, the air-sunlight (A-SL), air-light (AL), air-dark (AD) and nitrogen-dark (ND). X-ray diffraction (XRD) analysis showed that the pure and iron-doped TiO2 nanoparticles were in 100% anatase crystalline phase with crystai sizes of 108 and 65 nm, respectively. Adsorption of arsenic on the three adsorbents was non-linear that could be described by the Freundlich and Langmuir adsorption models. Iron doping enhanced the adsorption capacity of TiO2 nanoparticles by arresting the grain growth and making it visible light responsive resulting in a higher affinity for arsenic. Similarly, the arsenic removal by adsorption on the sand coated with TiO2 nanoparticles was the highest among the three types of sand used. In all cases, As(V) was adsorbed more compared with As(Ⅲ). The solution pH appeared to be the most important factor in controlling the amount of arsenic adsorbed.展开更多
Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-Ti02) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal proper...Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-Ti02) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO2 nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of Ti02 nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO2 films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.展开更多
Preparing titanium dioxide from titania-rich slag (TiO2 73wt%) by molten NaOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed ...Preparing titanium dioxide from titania-rich slag (TiO2 73wt%) by molten NaOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed that temperature had significant influence on the titanium conversion as well as the structure of the product. About 92% of titanium in the titania-rich slag could be converted after reacting with NaOH at 500℃ for 1 h. Metatitanic acid was formed through the steps of washing treatment, acid dissolution, and hydrolysis. Well-dispersed spherical titanium dioxide particles with an average size of 0.1-0.4μm can be obtained by calcination of metatitanic acid. In addition, the content of titanium dioxide in the product is up to 98.6wt%, which can be used as pigments after further treatment of coating and crushing.展开更多
In this study, we report the cost-effective and simple synthesis of carbon-coated α-MnOnanoparticles(α-MnO@C) for use as cathodes of aqueous zinc-ion batteries(ZIBs) for the first time. α-MnO@C was prepared via a g...In this study, we report the cost-effective and simple synthesis of carbon-coated α-MnOnanoparticles(α-MnO@C) for use as cathodes of aqueous zinc-ion batteries(ZIBs) for the first time. α-MnO@C was prepared via a gel formation, using maleic acid(CHO) as the carbon source, followed by annealing at low temperature of 270 °C. A uniform carbon network among the α-MnOnanoparticles was observed by transmission electron microscopy. When tested in a zinc cell, the α-MnO@C exhibited a high initial discharge capacity of 272 m Ah/g under 66 m A/g current density compared to 213 m Ah/g, at the same current density, displayed by the pristine sample. Further, α-MnO@C demonstrated superior cycleability compared to the pristine samples. This study may pave the way for the utilizing carbon-coated MnOelectrodes for aqueous ZIB applications and thereby contribute to realizing high performance eco-friendly batteries.展开更多
Titanium dioxide Nanotubes(TNTs) prepared by electroless deposition have been annealed at air ambient and low temperature. As a result, the anatase/rutile phase composition of the TNTs can be tailored to the needs of ...Titanium dioxide Nanotubes(TNTs) prepared by electroless deposition have been annealed at air ambient and low temperature. As a result, the anatase/rutile phase composition of the TNTs can be tailored to the needs of later applications. Nanotubes with anatase/rutile mixed phase ratio of 4:1 have been produced in this report and further examined for their photocatalytical behavior. The photocatalytical properties of the TNTs have been observed by degradation of methylene-blue in aqueous solution under low power UV-light irradiation. The results shown in this report are based on the synergetic effect between rutile and anatase,which results in the mixed phase TiO 2 nanotubes having enhanced photocatalytical properties.展开更多
Grafting of polymer of methyl methacrylate (PMMA) onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatmen...Grafting of polymer of methyl methacrylate (PMMA) onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.展开更多
Electrostatic self-assembly method (ESAM) was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction (XRD), fourier transform infrared spect...Electrostatic self-assembly method (ESAM) was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.展开更多
AIM: To investigate the impact of titanium dioxide nanoparticles(Ti O2NPs) on embryonic development and retinal neurogenesis.METHODS: The agglomeration and sedimentation of Ti O2 NPs solutions at different dilutions w...AIM: To investigate the impact of titanium dioxide nanoparticles(Ti O2NPs) on embryonic development and retinal neurogenesis.METHODS: The agglomeration and sedimentation of Ti O2 NPs solutions at different dilutions were observed,and the ultraviolet-visible spectra of their supernatants were measured. Zebrafish embryos were experimentally exposed to Ti O2 NPs until 72 h postfertilization(hpf). The retinal neurogenesis and distribution of the microglia were analyzed by immunohistochemistry and whole mount in situ hybridization.RESULTS: The 1 mg/L was determined to be an appropriate exposure dose. Embryos exposed to Ti O2 NPs had a normal phenotype. The neurogenesis was initiated on time, and ganglion cells, cones and rods were well differentiated at 72 hpf. The expression of fms m RNA and the 4C4 antibody, which were specific to microglia in the central nervous system(CNS), closely resembled their endogenous profile.CONCLUSION: These data demonstrate that short-term exposure to Ti O2 NPs at a low dose does not lead to delayed embryonic development or retinal neurotoxicity.展开更多
Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray diffraction(XRD), transmission el...Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray diffraction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), and N2 adsorption-desorption isotherms confirms that the sample has a mesostructure with a higher specific surface area and shows that the mesoporous TiO2 spheres have a diameter of 2 μm, the average pore size is about 5.9 nm, and the BET surface area and specific pore volume are about 236 m2/g and 2.116 cm3/g, respectively. The anatase and rutile mesoporous TiO2 spheres calcined at 700 °C show much better photocatalytic activity than the samples calcined at other temperatures and is comparable to an uncalcined sample in the photodegradation of Methyl Blue(MB) under the UV irradiation.展开更多
Dip-coated double-wall carbon nanotubes(DWCNTs) and titanium dioxide(TiO2) sol have been prepared and smeared onto the tip of a conductive iron needle which serves as the corona discharge anode in a needle-cylinder co...Dip-coated double-wall carbon nanotubes(DWCNTs) and titanium dioxide(TiO2) sol have been prepared and smeared onto the tip of a conductive iron needle which serves as the corona discharge anode in a needle-cylinder corona system.Compared with the discharge electrode of a CNT-coated needle tip, great advancements have been achieved with the TiO_2/CNT-coated electrode, including higher discharge current, ionic wind velocity, and energy conversion efficiency,together with lower corona onset voltage and power consumption.Several parameters related to the discharge have been phenomenologically and mathematically studied for comparison.Thanks to the morphology reorientation of the CNT layer and the anti-oxidation of TiO_2, better performance of corona discharge induced wind generation of the TiO2/CNT-coated electrode system has been achieved.This novel decoration may provide better thoughts about the corona discharge application and wind generation.展开更多
文摘The use of titanium dioxide nanoparticles (nTiO<sub>2</sub>) is gaining interest in agriculture because of their impact on many aspects of plant growth. The present study examines the effects of nTiO<sub>2</sub> (5 nm and 10 nm) applied to seeds and the seedlings as a foliar application on various aspects of growth characteristics and biomass accumulation in lettuce (Lactuca sativa, cv. Grand Rapids). Application of 10 nm nTiO<sub>2</sub> to seeds through imbibition resulted in a significant reduction in shoot biomass accumulation while 5 nm nTiO<sub>2</sub> did not affect the biomass accumulation in lettuce. The application of 10 nm nTiO<sub>2</sub> reduced the fresh shoot biomass accumulation by about 18% compared to the control plants. Other growth characteristics such as shoot dry biomass, root fresh and dry biomass, plant height, and leaf area were not affected by the application of both 5 nm and 10 nm nTiO<sub>2</sub>. In addition, foliar application of these nanoparticles to the lettuce seedlings did not have a significant effect on most of the growth parameters examined, and the increasing concentration ranging from 5 nm/L to 400 mg/L did not produce a consistent response in lettuce. Thus, nTiO<sub>2</sub> application to lettuce seeds had a notable negative impact on shoot growth while foliar application did not have a significant effect on many plant growth characteristics. However, foliar applications produced some symptoms of toxicity to the foliage in the form of necrotic or chlorotic patches on the leaves, which were more pronounced with increasing concentrations of both 5 nm and 10 nm nTiO<sub>2</sub>. However, these symptoms were apparent at a concentration as low as 50 mg/L of nTiO<sub>2</sub>. Thus, foliar application of nTiO<sub>2</sub> may not have a significant impact on many of the growth characteristics in lettuce, but it can result in foliar toxicity.
基金Ho Chi Minh City University of Technology (HCMUT),VNU-HCM for supporting this study。
文摘In this study,three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide(Mg Fe_2O_(4)-GM/TiO_(2)/rGO(MGTG))was successfully synthesized via green and hydrothermal-supported co-precipitation methods using the extract of Garcinia mangostana(G.mangostana)as a reducing agent.The characterization results indicate the successful formation of the nano/micro Mg Fe_(2)O_(4)(MFO)and TiO_(2) on the structure of the reduced graphene oxide(rGO),which can also act as efficient support,alleviating the agglomeration of the nano/micro MFO and TiO_(2).The synergic effects of the adsorption and photodegradation activity of the material were investigated according to the removal of crystal violet(CV)under ultraviolet light.The effects of catalyst dosage,CV concentration,and p H on the CV removal efficiency of the MGTG were also investigated.According to the results,the CV photodegradation of the MGTG-200 corresponded to the pseudo-first-order kinetic model.The reusability of the material after 10 cycles also showed a removal efficiency of 92%.This happened because the materials can easily be recollected using external magnets.In addition,according to the effects of different free radicals·O_(2)^(-),h^(+),and·OH on the photodegradation process,the photocatalysis mechanism of the MGTG was also thoroughly suggested.The antibacterial efficiency of the MGTG was also evaluated according to the inhibition of the Gram-positive bacteria strain Staphylococcus aureus(S.aureus).Concurrently,the antibacterial mechanism of the fabricated material was also proposed.These results confirm that the prepared material can be potentially employed in a wide range of applications,including wastewater treatment and antibacterial activity.
基金financially supported by the National Natural Science Foundation of China (No.51874099)the National Science Foundation of Fujian Province’s Key Project,China (No.2021J02031)the support from the open fund from the Academy of Carbon Neutrality of Fujian Normal University,China (No.CZH2022-06)。
文摘To meet the low-cost concept advocated by the sodium metal anode,this paper reports the use of a pulsed electrodeposition technology with ionic liquids as electrolytes to achieve uniform nanoplating of metallic magnesium films at around 20 nm on spaced titanium dioxide(TiO_(2))nanotubes(STNA-Mg).First,the sodiophilic magnesium metal coating can effectively reduce the nucleation overpotential of sodium metal.Moreover,three-dimensional STNA can limit the volume expansion during sodium metal plating and stripping to achieve the ultrastable deposition and stripping of sodium metals with a high Coulombic efficiency of up to 99.5%and a small voltage polarization of 5 mV in symmetric Na||Na batteries.In addition,the comparative study of sodium metal deposition behavior of STNA-Mg and STNA-Cu prepared by the same route further confirmed the advantage of magnesium metal to guide sodium metal growth.Finally,the prepared STNA-Mg-Na metal anode and commercial sodium vanadium phosphate cathode were assembled into a full cell,delivering a discharge capacity of 110.2 mAh·g^(-1)with a retention rate of 95.6%after 110 cycles at 1C rate.
基金supported by the National Natural Science Foundation of China(No.22108108,22205108,and No.22108106)China Postdoctoral Science Foundation No.2022M721381.
文摘Extremely high-temperature and high-pressure requirement of Haber-Bosch process motivates the search for a sustainable ammonia synthesis approach under mild conditions.Photocatalytic technology is a potential solution to convert N2 to ammonia.However,the poor light absorption and low charge carrier separation efficiency in conventional semiconductors are bottlenecks for the application of this technology.Herein,a facile synthesis of anatase TiO_(2)nanosheets with an abundance of surface oxygen vacancies(TiO_(2)-OV)via the calcination treatment was reported.Photocatalytic experiments of the prepared anatase TiO_(2)samples showed that TiO_(2)-OV nanosheets exhibited remarkably increased ammonia yield for solar-driven N2 fixation in pure water,without adding any sacrificial agents.EPR,XPS,XRD,UV-Vis DRS,TEM,Raman,and PL techniques were employed to systematically explore the possible enhanced mechanism.Studies revealed that the introduced surface oxygen vacancies significantly extended the light absorption capability in the visible region,decreased the adsorption and activation barriers of inert N2,and improved the separation and transfer efficiency of the photogenerated electronhole pairs.Thus,a high rate of ammonia evolution in TiO_(2)-OV was realized.This work offers a promising and sustainable approach for the efficient artificial photosynthesis of ammonia.
基金Supported by the National Natural Science Foundation of China(No.20076042,No.20206029)and the Scientific Research Foundation of the State Education Ministry for the Returned Overseas Chinese Scholars(No.2002-247).
文摘Expanded bed adsorption (EBA) has been widely used in industrial downstream bioprocessing,Solid matrix is the principal pillar supporting the successful application of EBA.A novel spherical ceelulose-titanium dioxide composite matrix was prepared through the method of water-in-oil suspension thermal regeneration.Its typical physical properties were wet density 1.18g.cm^-3,,diameters in the range of 100-300μm ,porosity 85.5%,and water content 72.3%.Expansion characteristics and liquid mixing performance of the matrix in expanded bed were investigated using water and 10% (by mass )glycerol solution as mobile phases,The results indicate that the custom-assembled matrix has a stable flow hydrodynamics and exhibits the same degree of liquid-phase mixing or column efficiency as the commercially available Streamline adsorbent.
文摘This study aims to prepare a composite polyurethane coating through a facile synthesis process. Titanium dioxide, which is a component of the prepared hydroxyl acrylic resin polyurethane varnish, was partially substituted by wollastonite, and an optimal substitution ratio was obtained. Analyses based on scanning electron microscope, powder X-ray diffraction, and Raman scattering measurements demonstrated that the addition of wollastonite caused nearly no change in the basic structure of the coating. Coating with a substitution ratio of 25% showed high thermal stability, good cover effect, considerable moisture-proof and water resistance ability, great acidic and basic resistance, and improved performance and hardness in performance tests. Furthermore, the production cost was reduced significantly at this substitution ratio.
文摘The aim of this study is to clarify the effect of different concentrations of titanium dioxide nanoparticles (Nps) on the properties of two types of heat polymerized acrylic resin. The tested parameters were flexural strength, impact strength, and microhardness. The two types of acrylic resin used in this study were conventional unmodified (Implacryl, Vertex) and high impact heat polymerized acrylic resin (Vertex-Dental, Netherlands). Both types of acrylic resin were modified by using 1% and 5% TiO<sub>2</sub> Nps powder. Specimen’s dimensions were prepared according to the American Dental Association Specification No. 12. Three types of specimens were prepared: 1) flexural strength specimens 50 mm × 10 (±0.2) mm × 3 (±0.2) mm, 2) impact strength test specimens 60 mm × 6.0 mm × 4.0 mm, 3) microhardnesss specimens 25 mm × 10 mm × 3 (±0.2) mm. For each test 6 groups were prepared (each group containing 5 samples). Thirty specimens were prepared in each of the three tests, amounting to a total number of 90 specimens. Mechanical properties such as flexural strength (FS), impact strength and microhardness of the above mentioned specimens were determined using universal testing machine, Izod pendulum impact testing machine and Vickers microhardness tester, respectively. ISO Specification No. 1567 was followed in microhardness test. The data was collected and statistically analyzed. Flexural strength considerably decreased by increasing TiO<sub>2</sub> concentration in both types of acrylic resin. Impact strength of the conventional acrylic resin modified by 1% of additives significantly increased. The microhardness is significantly increased by addition of 5% of TiO<sub>2</sub> Nps. The Incorporation of TiO<sub>2</sub> nanoparticles into acrylic resins can adversely affect its flexural strength. Meanwhile, the impact strength can be modified by small percentage of additives (abt. 1%). This effect is directly correlated with the concentration of nanoparticles. On the other hand, concentrations of TiO<sub>2</sub> Nps (abt. 5%) positively affect the microhardness of both types of acrylic resin used in the present study.</sub></sub></sub></sub></sub></sub></sub></sub></sub></sub>
文摘The preparation of a new mineral composite material, calcium carbonate particles coated with titanium dioxide, was studied. The mechanism of the preparation process was proposed. The new mineral composite material was made by the mechanoehemieal method under the optimum condition that the mass ratio of calcium carbonate particles to titanium dioxide was 6.5:3.5. The mass ratios of two different types of titanium dioxide (anatase to rutile) and grinding media to grinded materials were 8:2 and 4:1 respectively, and the modified density was 60%. Under this condition, the new material was capable of forming after 120-min modification. The hiding power and oil absorption of this new material were 29.12 g/m^2 and 23.30%, respectively. The results show that the modification is based on surface hydroxylation. After coating with titanium dioxide, the hiding power of calcium carbonate can be improved greatly. The new mineral composite materials can be used as the substitute for titanium dioxide.
文摘The adsorption potential of titanium dioxide (TiO2) nanoparticles for removing arsenic from drinking water was evaluated. Pure and iron-doped TiO2 particles are synthesized via sol-gel method. The synthesized TiO2 nanoparticles were then immobilized on ordinary sand for adsorption studies. Adsorption isotherms were conducted on the synthesized nanoparticles as well as the sand coated with TiO2 nanoparticles under varying conditions of air and light, namely, the air-sunlight (A-SL), air-light (AL), air-dark (AD) and nitrogen-dark (ND). X-ray diffraction (XRD) analysis showed that the pure and iron-doped TiO2 nanoparticles were in 100% anatase crystalline phase with crystai sizes of 108 and 65 nm, respectively. Adsorption of arsenic on the three adsorbents was non-linear that could be described by the Freundlich and Langmuir adsorption models. Iron doping enhanced the adsorption capacity of TiO2 nanoparticles by arresting the grain growth and making it visible light responsive resulting in a higher affinity for arsenic. Similarly, the arsenic removal by adsorption on the sand coated with TiO2 nanoparticles was the highest among the three types of sand used. In all cases, As(V) was adsorbed more compared with As(Ⅲ). The solution pH appeared to be the most important factor in controlling the amount of arsenic adsorbed.
基金financial support by Iran Nanotechnology Initiative Council
文摘Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-Ti02) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO2 nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of Ti02 nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO2 films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.
基金financially supported by the National Key Technologies R & D Program of China (No.2006BAC02A05)the National Basic Research Program of China (No. 2007CB613501)+1 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KGCX2-YW-214)the Special Funds of "Mountain Tai Scholar" Construction Project
文摘Preparing titanium dioxide from titania-rich slag (TiO2 73wt%) by molten NaOH method has been developed. The effects of temperature and reaction time on the titanium conversion were investigated. The results showed that temperature had significant influence on the titanium conversion as well as the structure of the product. About 92% of titanium in the titania-rich slag could be converted after reacting with NaOH at 500℃ for 1 h. Metatitanic acid was formed through the steps of washing treatment, acid dissolution, and hydrolysis. Well-dispersed spherical titanium dioxide particles with an average size of 0.1-0.4μm can be obtained by calcination of metatitanic acid. In addition, the content of titanium dioxide in the product is up to 98.6wt%, which can be used as pigments after further treatment of coating and crushing.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(2014R1A2A1A10050821)
文摘In this study, we report the cost-effective and simple synthesis of carbon-coated α-MnOnanoparticles(α-MnO@C) for use as cathodes of aqueous zinc-ion batteries(ZIBs) for the first time. α-MnO@C was prepared via a gel formation, using maleic acid(CHO) as the carbon source, followed by annealing at low temperature of 270 °C. A uniform carbon network among the α-MnOnanoparticles was observed by transmission electron microscopy. When tested in a zinc cell, the α-MnO@C exhibited a high initial discharge capacity of 272 m Ah/g under 66 m A/g current density compared to 213 m Ah/g, at the same current density, displayed by the pristine sample. Further, α-MnO@C demonstrated superior cycleability compared to the pristine samples. This study may pave the way for the utilizing carbon-coated MnOelectrodes for aqueous ZIB applications and thereby contribute to realizing high performance eco-friendly batteries.
基金Project supported by the State Key Laboratory of Urban Water Resource and Environment (HIT 08UWQA05) and National Key Laboratory of Vacuum and Cryogenics Technology and Physics (9140C550201060C55)
文摘Titanium dioxide Nanotubes(TNTs) prepared by electroless deposition have been annealed at air ambient and low temperature. As a result, the anatase/rutile phase composition of the TNTs can be tailored to the needs of later applications. Nanotubes with anatase/rutile mixed phase ratio of 4:1 have been produced in this report and further examined for their photocatalytical behavior. The photocatalytical properties of the TNTs have been observed by degradation of methylene-blue in aqueous solution under low power UV-light irradiation. The results shown in this report are based on the synergetic effect between rutile and anatase,which results in the mixed phase TiO 2 nanotubes having enhanced photocatalytical properties.
文摘Grafting of polymer of methyl methacrylate (PMMA) onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.
基金Funded by the Natural Science Foundation of Hebei Province, China (No. E2008000537)the Foundation for Development of Science and Technology of Hebei Province, China (No. 07215156)the Open Research Foundation of Key Laboratory of Advanced Civil Engineering Materials (Tongji University),Ministry of Education, China (No. 2010412)
文摘Electrostatic self-assembly method (ESAM) was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.
基金Supported by the National Natural Science Foundation of China (No.81301080)the National Key Technology R&D Program of China (2012BAI08B06)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry
文摘AIM: To investigate the impact of titanium dioxide nanoparticles(Ti O2NPs) on embryonic development and retinal neurogenesis.METHODS: The agglomeration and sedimentation of Ti O2 NPs solutions at different dilutions were observed,and the ultraviolet-visible spectra of their supernatants were measured. Zebrafish embryos were experimentally exposed to Ti O2 NPs until 72 h postfertilization(hpf). The retinal neurogenesis and distribution of the microglia were analyzed by immunohistochemistry and whole mount in situ hybridization.RESULTS: The 1 mg/L was determined to be an appropriate exposure dose. Embryos exposed to Ti O2 NPs had a normal phenotype. The neurogenesis was initiated on time, and ganglion cells, cones and rods were well differentiated at 72 hpf. The expression of fms m RNA and the 4C4 antibody, which were specific to microglia in the central nervous system(CNS), closely resembled their endogenous profile.CONCLUSION: These data demonstrate that short-term exposure to Ti O2 NPs at a low dose does not lead to delayed embryonic development or retinal neurotoxicity.
基金Supported by the National Natural Science Foundation of China(No.21076094)
文摘Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray diffraction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), and N2 adsorption-desorption isotherms confirms that the sample has a mesostructure with a higher specific surface area and shows that the mesoporous TiO2 spheres have a diameter of 2 μm, the average pore size is about 5.9 nm, and the BET surface area and specific pore volume are about 236 m2/g and 2.116 cm3/g, respectively. The anatase and rutile mesoporous TiO2 spheres calcined at 700 °C show much better photocatalytic activity than the samples calcined at other temperatures and is comparable to an uncalcined sample in the photodegradation of Methyl Blue(MB) under the UV irradiation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61504042,61504098,and 61771198)the Natural Science Foundation of Shanghai,China(Grant No.17ZR1447000)the Fundamental Research Funds for the Central Universities,China
文摘Dip-coated double-wall carbon nanotubes(DWCNTs) and titanium dioxide(TiO2) sol have been prepared and smeared onto the tip of a conductive iron needle which serves as the corona discharge anode in a needle-cylinder corona system.Compared with the discharge electrode of a CNT-coated needle tip, great advancements have been achieved with the TiO_2/CNT-coated electrode, including higher discharge current, ionic wind velocity, and energy conversion efficiency,together with lower corona onset voltage and power consumption.Several parameters related to the discharge have been phenomenologically and mathematically studied for comparison.Thanks to the morphology reorientation of the CNT layer and the anti-oxidation of TiO_2, better performance of corona discharge induced wind generation of the TiO2/CNT-coated electrode system has been achieved.This novel decoration may provide better thoughts about the corona discharge application and wind generation.