This study focused on the development and characterization of TiO<sub>2</sub>-PES composite fibers with varying TiO<sub>2</sub> loading amounts using a phase inversion process. The resulting co...This study focused on the development and characterization of TiO<sub>2</sub>-PES composite fibers with varying TiO<sub>2</sub> loading amounts using a phase inversion process. The resulting composite fibers exhibited a sponge-like structure with embedded TiO<sub>2</sub> nanoparticles within a polymer matrix. Their photocatalytic performance for ammonia removal from aqueous solutions under UV-A light exposure was thoroughly investigated. The findings revealed that PeTi8 composite fibers displayed superior adsorption capacity compared to other samples. Moreover, the study explored the impact of pH, light intensity, and catalyst dosage on the photocatalytic degradation of ammonia. Adsorption equilibrium isotherms closely followed the Langmuir model, with the results indicating a correlation between qm values of 2.49 mg/g and the porous structure of the adsorbents. The research underscored the efficacy of TiO<sub>2</sub> composite fibers in the photocatalytic removal of aqueous under UV-A light. Notably, increasing the distance between the photocatalyst and the light source resulted in de-creased hydroxyl radical concentration, influencing photocatalytic efficiency. These findings contribute to our understanding of TiO<sub>2</sub> composite fibers as promising photocatalysts for ammonia removal in water treatment applications.展开更多
Modern communication technologies put forward higher requirements for electromagnetic wave(EMW)absorption materials.Metal-organic framework(MOF)derivatives have been widely concerned with its diverse advantages.To bre...Modern communication technologies put forward higher requirements for electromagnetic wave(EMW)absorption materials.Metal-organic framework(MOF)derivatives have been widely concerned with its diverse advantages.To break the mindset of magneticderivative design,and make up the shortage of monometallic non-magnetic derivatives,we first try non-magnetic bimetallic MOFs derivatives to achieve efficient EMW absorption.The porous carbon-wrapped TiO2/ZrTiO4 composites derived from PCN-415(TiZr-MOFs)are qualified with a minimum reflection loss of−67.8 dB(2.16 mm,13.0 GHz),and a maximum effective absorption bandwidth of 5.9 GHz(2.70 mm).Through in-depth discussions,the synergy of enhanced interfacial polarization and other attenuation mechanisms in the composites is revealed.Therefore,this work confirms the huge potentials of nonmagnetic bimetallic MOFs derivatives in EMW absorption applications.展开更多
Polyaniline (PAn) sensitized nanocrystalline TiO2 composites (TiO2/PAn) were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue (MB). The results showed that P...Polyaniline (PAn) sensitized nanocrystalline TiO2 composites (TiO2/PAn) were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue (MB). The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light (λ: 190 ~ 800 nm), whereas pure TiO2 absorbed ultraviolet light only (λ 〈 380 nm). Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore, it could be easily separated from the solution by simple sedimentation.展开更多
The uniform transparent TiO2/SiO2 photocatalytic composite thin films are prepared by sol-gel method on the soda lime glass substrates, and characterized by UV-visible spectroscopy, X-ray diffraction (XRD), transmissi...The uniform transparent TiO2/SiO2 photocatalytic composite thin films are prepared by sol-gel method on the soda lime glass substrates, and characterized by UV-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), BET surface area, FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the addition of SiO2 to TiO2 thin films can suppress the grain growth of TiO2 crystal, increase the hydroxyl content on the surface of TiO2 films, lower the contact angle for water on TiO, films and enhance the hydrophilic property of TiO2 films. The super-hydrophilic TiO2/SiO2 photocatalytic composite thin films with the contact angle of 0((o) under bar) are obtained by the addition of 10%-20% SiO2 in mole fraction.展开更多
TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane (γ-HCH) in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocataly...TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane (γ-HCH) in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocatalysts were exposed to UV-light irradiation. The results indicated that the photocatalytic activities of the composite photocatalysts varied with the content of TiO2 in the order of 10%〈70%〈50% 〈30%, Moreover, the photocatalytic activity of the composite photocatalysts with TiO2 content 30% was higher than that of the pure P25 with the same mass of TiO2. The strong adsorption capacity of the composite photocatalysts and quantum size effect may contribute to its increased photocatalytic activities. In addition, effect of dosage of composite photocatalysts and soil pH on γ-HCH photodegradation was investigated. Pentachlorocyclohexene, trichlorocyclohexene, and dichlorobenzene were detected as photodegradation intermediates, which were gradually degraded with the photodegradation evolution.展开更多
Calcined kaolin/TiO2 composite particle material (CK/TCPM) was prepared with TiO2 coating on the surfaces of calcined kaolin particles by the mechano-chemical method. X-ray diffraction (XRD) and scanning electron ...Calcined kaolin/TiO2 composite particle material (CK/TCPM) was prepared with TiO2 coating on the surfaces of calcined kaolin particles by the mechano-chemical method. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to investigate the microstructures and morphologies, respectively. The mechanism of the mechano-chemical reaction between calcined kaolin and TiO2 was studied by infrared spectra (IR). The results show that TiO2 coats evenly on the surfaces of calcined kaolin particles by Si-O-Ti and Al-O-Ti bonds on their interfaces. The hiding power and whiteness of CK/TCPM are 17.12 g/m^2 and 95.7%, respectively, presenting its similarity to TiO2 in pigment properties.展开更多
Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to de...Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to develop biomaterial/TiO2 composite photocatalysts is a promising method to remove these trace pollutants because of the synergistic effect. Biomaterials provide multiple function groups which can selectively and efficiently enrich trace pollutants onto the surface of the photocatalysts, thus facilitating the following transformation mediated by TiO2 photocatalysis. Biomaterials can also help the dispersion and recovery of TiO2, or even modify the band structure of TiO2. The fabrication of chitosan/TiO2, cellulose/TiO2, as well as other biomaterial/TiO2 composite photocatalysts is discussed in detail in this review. The application significance of these composite photocatalysts for the selective removal of trace pollutants is also addressed. Several problems should be solved before the realistic applications can be achieved as discussed in the final section.展开更多
A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion...A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM (environmental scanning electron microscopy) and EIS (electrochemical impedance spectroscopy) measurements. Results showed that the NiP/ TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS (X-ray photoelectron spectroscopy) spectrum, and an anticorrosion mechanism of the composite film was discussed.展开更多
The wettability of the membrane surface has shown obvious influent on the separation performance of the membrane.In this work,a hydrophilic PDA-[PDDA/TiO2]+Cl-membrane was prepared by a one-step codeposition of poly(d...The wettability of the membrane surface has shown obvious influent on the separation performance of the membrane.In this work,a hydrophilic PDA-[PDDA/TiO2]+Cl-membrane was prepared by a one-step codeposition of poly(diallyldimethylammonium chloride)(PDDA)polyelectrolyte solution containing positively charged TiO2@PDDA nanoparticles with the assistance of dopamine(DA).Such positively charged membrane can be transformed into a hydrophobic membrane PDA-[PDDA/TiO2]+PFO-via the counterion exchange between Cl-and PFO-(perfluorooctanoate).The transformation between hydrophilicity and hydrophobicity is reversible.For both hydrophilic and hydrophobic membranes,the nanofiltration performances were respectively investigated by the aqueous solution and ethanol solution of dyes including methyl blue(MB),Congo red(CR)and Evans blue(EB),and as well metal salt aqueous solution.The consecutive running stability and anti-fouling performance of both hydrophilic and hydrophobic membranes were explored.The results revealed that both membranes showed high nanofiltration performances for retention of dyes in(non)aqueous solution.For the hydrophilic membrane,the rejection of salts in a sequence is MgSO4>Na2SO4>MgCl2>NaCl.Moreover,both of the hydrophilic and hydrophobic membranes showed high stability and antifouling property.展开更多
A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sens...A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra (DRS) revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.展开更多
TiO2 filled polytetrafluoroethylene (PTFE) composite were fabricated for microwave circuit applications. PTFE/TiO2 composites were prepared by cold pressing and hot treating. The particle size of TiO2 varied from 5 μ...TiO2 filled polytetrafluoroethylene (PTFE) composite were fabricated for microwave circuit applications. PTFE/TiO2 composites were prepared by cold pressing and hot treating. The particle size of TiO2 varied from 5 μm to 11 μm.TiO2 powders with different sizes were prepared by the solid state ceramic route. The effects of TiO2 particle size on the microstructure, density, moisture absorption, thermal conductivity and microwave dielectric properties of PTFE/TiO2 composites were investigated. The density showed an increasing trend as the TiO2 particle size increased, while the dielectric loss (tanδ) and moisture absorption decreased with the increase of TiO2 particle size. The dielectric constant (εr) and thermal conductivity (λ) decreased up to D50 = 6.5 μm and then sharply increased. Good properties with values of εr = 6.8, tanδ = 0.0012 and λ = 0.533 W?m?1?K?1 were obtained in PTFE/TiO2 composites when the particle size of TiO2 was 11 μm.展开更多
In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performanc...In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.展开更多
In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to thei...In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (Tg), the melting temperature (Tm), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo- polymers PMMA and nano-TiO2 powder is possible.The results showed that nano-TiO2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, lead- ing to interesting technological applications.展开更多
We report a facile method for the fabrication of TiO2 nanofiber-nanoparticle composite (FP) via. simulta- neous electrospraying and electrospinning for dye-sensitized solar cell (DSC) applications. The loading of ...We report a facile method for the fabrication of TiO2 nanofiber-nanoparticle composite (FP) via. simulta- neous electrospraying and electrospinning for dye-sensitized solar cell (DSC) applications. The loading of nanoparticles on the fibers is controlled by varying their feed rates during electrospinning. The FP composites having three different particle loading are prepared by the methodology and the FP with the highest particle loading (denoted as FP-3 in the manuscript) showed the best overall efficiency of 9.15% in comparison to the other compositions of the FP (FP-2, 8.15% and FP-1, Z51%, respectively) and nanofibers (F) and nanoparticles (P) separately (7.21 and 7.81, respectively). All the material systems are characterized by spec- troscopy, microscopy, surface area measurements and the devices are characterized by current-voltage (I-V), incident photon-to-current conversion efficiency (IPCE), electrochemical impedance measurements, etc. I-V, dye-loading and reflectance measurements throw light on the overall performance of the DSC devices.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
Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 ...Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.展开更多
Ablation under oxyacetylene torch with heat flux of 4186.8(10%kW/m2 for 20 s was performed to evaluate the ablation resistance of C/C-SiC composites fabricated by chemical vapor infiltration(CVI) combined with liqu...Ablation under oxyacetylene torch with heat flux of 4186.8(10%kW/m2 for 20 s was performed to evaluate the ablation resistance of C/C-SiC composites fabricated by chemical vapor infiltration(CVI) combined with liquid silicon infiltration(LSI) process.The results indicated that C/C-SiC composites present a better ablation resistance than C/C composites without doped SiC.The doped SiC and the ablation products SiO2 derived from it play key roles in ablation process.Bulk quantities of SiO2 nanowires with diameter of 80 nm-150 nm and length of tens microns were observed on the surface of specimens after ablation.The growth mechanism of the SiO_2 nanowires was interpreted with a developed vapor-liquid-solid(VLS) driven by the temperature gradient.展开更多
A type of TiO/bamboo charcoal composite made by a dip-dry method was loaded onto wood veneer with a vacuum- pressure method in order to prepare modified poplar veneer. The pore structure parameters and surface morphol...A type of TiO/bamboo charcoal composite made by a dip-dry method was loaded onto wood veneer with a vacuum- pressure method in order to prepare modified poplar veneer. The pore structure parameters and surface morphology of the TiO2/ bamboo charcoal composite were determined and analyzed by means of a porosimetry analyzer and SEM. The results show that the surface morphology of the composite does not change after being loaded with nano TiO2. However, its specific surface area (359.814 m^2·g^-1), pore volume (0.317 cm^3.g^-1) and average pore diameter (3.526 nm) increased; particularly the cumulative volume of pores was increased by 65.83%. In addition, the distribution range of the pores was wider than that of the bamboo charcoal. Combining the SEM of unmodified and modified poplar veneer, the results of X-ray photoelectron spectroscopy revealed that actually some TiOz compounds, i.e., 4.08%, are imbedded in the modified poplar veneer.展开更多
文摘This study focused on the development and characterization of TiO<sub>2</sub>-PES composite fibers with varying TiO<sub>2</sub> loading amounts using a phase inversion process. The resulting composite fibers exhibited a sponge-like structure with embedded TiO<sub>2</sub> nanoparticles within a polymer matrix. Their photocatalytic performance for ammonia removal from aqueous solutions under UV-A light exposure was thoroughly investigated. The findings revealed that PeTi8 composite fibers displayed superior adsorption capacity compared to other samples. Moreover, the study explored the impact of pH, light intensity, and catalyst dosage on the photocatalytic degradation of ammonia. Adsorption equilibrium isotherms closely followed the Langmuir model, with the results indicating a correlation between qm values of 2.49 mg/g and the porous structure of the adsorbents. The research underscored the efficacy of TiO<sub>2</sub> composite fibers in the photocatalytic removal of aqueous under UV-A light. Notably, increasing the distance between the photocatalyst and the light source resulted in de-creased hydroxyl radical concentration, influencing photocatalytic efficiency. These findings contribute to our understanding of TiO<sub>2</sub> composite fibers as promising photocatalysts for ammonia removal in water treatment applications.
基金The authors acknowledge funding from the National Natural Science Foundation of China(Nos.51572157,21902085,and 51702188)Natural Science Foundation of Shandong Province(No.ZR2019QF012)+1 种基金Fundamental Research Funds for the Central Universities(No.2018JC036 and No.2018JC046)Young Scholars Program of Shandong University(No.2018WLJH25).
文摘Modern communication technologies put forward higher requirements for electromagnetic wave(EMW)absorption materials.Metal-organic framework(MOF)derivatives have been widely concerned with its diverse advantages.To break the mindset of magneticderivative design,and make up the shortage of monometallic non-magnetic derivatives,we first try non-magnetic bimetallic MOFs derivatives to achieve efficient EMW absorption.The porous carbon-wrapped TiO2/ZrTiO4 composites derived from PCN-415(TiZr-MOFs)are qualified with a minimum reflection loss of−67.8 dB(2.16 mm,13.0 GHz),and a maximum effective absorption bandwidth of 5.9 GHz(2.70 mm).Through in-depth discussions,the synergy of enhanced interfacial polarization and other attenuation mechanisms in the composites is revealed.Therefore,this work confirms the huge potentials of nonmagnetic bimetallic MOFs derivatives in EMW absorption applications.
文摘Polyaniline (PAn) sensitized nanocrystalline TiO2 composites (TiO2/PAn) were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue (MB). The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light (λ: 190 ~ 800 nm), whereas pure TiO2 absorbed ultraviolet light only (λ 〈 380 nm). Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore, it could be easily separated from the solution by simple sedimentation.
基金This work was financially supported by the Foundation for University Key Teachers by the Ministry of Education, theKey Resear
文摘The uniform transparent TiO2/SiO2 photocatalytic composite thin films are prepared by sol-gel method on the soda lime glass substrates, and characterized by UV-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), BET surface area, FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the addition of SiO2 to TiO2 thin films can suppress the grain growth of TiO2 crystal, increase the hydroxyl content on the surface of TiO2 films, lower the contact angle for water on TiO, films and enhance the hydrophilic property of TiO2 films. The super-hydrophilic TiO2/SiO2 photocatalytic composite thin films with the contact angle of 0((o) under bar) are obtained by the addition of 10%-20% SiO2 in mole fraction.
基金Project supported by the National Natural Science Foundation of China(No. 29977003, 20507011)the State Ministry of Education of China(No. 00028)
文摘TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane (γ-HCH) in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocatalysts were exposed to UV-light irradiation. The results indicated that the photocatalytic activities of the composite photocatalysts varied with the content of TiO2 in the order of 10%〈70%〈50% 〈30%, Moreover, the photocatalytic activity of the composite photocatalysts with TiO2 content 30% was higher than that of the pure P25 with the same mass of TiO2. The strong adsorption capacity of the composite photocatalysts and quantum size effect may contribute to its increased photocatalytic activities. In addition, effect of dosage of composite photocatalysts and soil pH on γ-HCH photodegradation was investigated. Pentachlorocyclohexene, trichlorocyclohexene, and dichlorobenzene were detected as photodegradation intermediates, which were gradually degraded with the photodegradation evolution.
基金Funded by the National Key Technology R&D Program of China(No.2008BAE60B06)Beijing Municipal Science&Technology Commission (No.Z080003032208015)
文摘Calcined kaolin/TiO2 composite particle material (CK/TCPM) was prepared with TiO2 coating on the surfaces of calcined kaolin particles by the mechano-chemical method. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to investigate the microstructures and morphologies, respectively. The mechanism of the mechano-chemical reaction between calcined kaolin and TiO2 was studied by infrared spectra (IR). The results show that TiO2 coats evenly on the surfaces of calcined kaolin particles by Si-O-Ti and Al-O-Ti bonds on their interfaces. The hiding power and whiteness of CK/TCPM are 17.12 g/m^2 and 95.7%, respectively, presenting its similarity to TiO2 in pigment properties.
基金Supported by the National Natural Science Foundation of China(21525625,21838001)the National Basic Research Program(973 Program)of China(2014CB745100)+1 种基金the(863)High Technology Project of China(2013AA020302)the Chinese Universities Scientific Fund(JD1417)
文摘Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to develop biomaterial/TiO2 composite photocatalysts is a promising method to remove these trace pollutants because of the synergistic effect. Biomaterials provide multiple function groups which can selectively and efficiently enrich trace pollutants onto the surface of the photocatalysts, thus facilitating the following transformation mediated by TiO2 photocatalysis. Biomaterials can also help the dispersion and recovery of TiO2, or even modify the band structure of TiO2. The fabrication of chitosan/TiO2, cellulose/TiO2, as well as other biomaterial/TiO2 composite photocatalysts is discussed in detail in this review. The application significance of these composite photocatalysts for the selective removal of trace pollutants is also addressed. Several problems should be solved before the realistic applications can be achieved as discussed in the final section.
文摘A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM (environmental scanning electron microscopy) and EIS (electrochemical impedance spectroscopy) measurements. Results showed that the NiP/ TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS (X-ray photoelectron spectroscopy) spectrum, and an anticorrosion mechanism of the composite film was discussed.
基金financially supported by the National Natural Science Foundation of China(21476005,21878003)the National Natural Science Fund for Innovative Research Groups(51621003)。
文摘The wettability of the membrane surface has shown obvious influent on the separation performance of the membrane.In this work,a hydrophilic PDA-[PDDA/TiO2]+Cl-membrane was prepared by a one-step codeposition of poly(diallyldimethylammonium chloride)(PDDA)polyelectrolyte solution containing positively charged TiO2@PDDA nanoparticles with the assistance of dopamine(DA).Such positively charged membrane can be transformed into a hydrophobic membrane PDA-[PDDA/TiO2]+PFO-via the counterion exchange between Cl-and PFO-(perfluorooctanoate).The transformation between hydrophilicity and hydrophobicity is reversible.For both hydrophilic and hydrophobic membranes,the nanofiltration performances were respectively investigated by the aqueous solution and ethanol solution of dyes including methyl blue(MB),Congo red(CR)and Evans blue(EB),and as well metal salt aqueous solution.The consecutive running stability and anti-fouling performance of both hydrophilic and hydrophobic membranes were explored.The results revealed that both membranes showed high nanofiltration performances for retention of dyes in(non)aqueous solution.For the hydrophilic membrane,the rejection of salts in a sequence is MgSO4>Na2SO4>MgCl2>NaCl.Moreover,both of the hydrophilic and hydrophobic membranes showed high stability and antifouling property.
基金This project was financially supported by Specialized Research Fund for the Doctoral Program of Higher Education (No. 20050225006)the National Natural Science Foundation of China (No. 30400339).
文摘A high active novel TiO2/AC composite photocatalyst was prepared and used for phenol degradation. It was much more active than P-25 and exhibiting good decantability, less deactivation after several runs and less sensitive to pH change. Diffuse reflectance spectra (DRS) revealed that the electronic change in TiO2 did not occur by the addition of AC. Results of SEM and XRD suggested that better TiO2 distribution can be achieved when optimal AC content was adopted. The performance of the prepared TiO2/5AC catalyst revealed great practical potential in wastewater treatment field.
文摘TiO2 filled polytetrafluoroethylene (PTFE) composite were fabricated for microwave circuit applications. PTFE/TiO2 composites were prepared by cold pressing and hot treating. The particle size of TiO2 varied from 5 μm to 11 μm.TiO2 powders with different sizes were prepared by the solid state ceramic route. The effects of TiO2 particle size on the microstructure, density, moisture absorption, thermal conductivity and microwave dielectric properties of PTFE/TiO2 composites were investigated. The density showed an increasing trend as the TiO2 particle size increased, while the dielectric loss (tanδ) and moisture absorption decreased with the increase of TiO2 particle size. The dielectric constant (εr) and thermal conductivity (λ) decreased up to D50 = 6.5 μm and then sharply increased. Good properties with values of εr = 6.8, tanδ = 0.0012 and λ = 0.533 W?m?1?K?1 were obtained in PTFE/TiO2 composites when the particle size of TiO2 was 11 μm.
文摘In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.
文摘In the present work, composites of poly (methyl methacrylate)/titanium oxide nanoparticles (100/0, 97.5/2.5, 95/5, 92.5/7.5, 90/10 and 0/100 wt/wt%)were prepared to be used as bioequivalent materials according to their importance broad practical and medical applications. Thermal properties as well as X-ray diffraction analyses were employed to characterize the structure properties of such composite. The obtained results showed variations in the glass transition temperature (Tg), the melting temperature (Tm), shape and area of thermal peaks which were attributed to the different degrees of crystallinity and the existence of interactions between PMMA and TiO2 nanoparticle molecules. The XRD patterns showed sharpening of peaks at different concentrations of nano-TiO2 powder with PMMA. This indicated changes in the crystallinity/amorphosity ratio, and also suggested that the miscibility between the amorphous components of homo- polymers PMMA and nano-TiO2 powder is possible.The results showed that nano-TiO2 powder mix with PMMA can improve the thermal stability of the homo-polymer under investigation, lead- ing to interesting technological applications.
基金supported by Ministry of New and Renewable Energy(MNRE)the Solar Energy Research Initiative(SERI),respectively.of Govt.of India
文摘We report a facile method for the fabrication of TiO2 nanofiber-nanoparticle composite (FP) via. simulta- neous electrospraying and electrospinning for dye-sensitized solar cell (DSC) applications. The loading of nanoparticles on the fibers is controlled by varying their feed rates during electrospinning. The FP composites having three different particle loading are prepared by the methodology and the FP with the highest particle loading (denoted as FP-3 in the manuscript) showed the best overall efficiency of 9.15% in comparison to the other compositions of the FP (FP-2, 8.15% and FP-1, Z51%, respectively) and nanofibers (F) and nanoparticles (P) separately (7.21 and 7.81, respectively). All the material systems are characterized by spec- troscopy, microscopy, surface area measurements and the devices are characterized by current-voltage (I-V), incident photon-to-current conversion efficiency (IPCE), electrochemical impedance measurements, etc. I-V, dye-loading and reflectance measurements throw light on the overall performance of the DSC devices.
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Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110006110025)the National Natural Science Foundation of China(Grant No.U1134102)
文摘Ablation under oxyacetylene torch with heat flux of 4186.8(10%kW/m2 for 20 s was performed to evaluate the ablation resistance of C/C-SiC composites fabricated by chemical vapor infiltration(CVI) combined with liquid silicon infiltration(LSI) process.The results indicated that C/C-SiC composites present a better ablation resistance than C/C composites without doped SiC.The doped SiC and the ablation products SiO2 derived from it play key roles in ablation process.Bulk quantities of SiO2 nanowires with diameter of 80 nm-150 nm and length of tens microns were observed on the surface of specimens after ablation.The growth mechanism of the SiO_2 nanowires was interpreted with a developed vapor-liquid-solid(VLS) driven by the temperature gradient.
基金A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions for financial support to conduct this research
文摘A type of TiO/bamboo charcoal composite made by a dip-dry method was loaded onto wood veneer with a vacuum- pressure method in order to prepare modified poplar veneer. The pore structure parameters and surface morphology of the TiO2/ bamboo charcoal composite were determined and analyzed by means of a porosimetry analyzer and SEM. The results show that the surface morphology of the composite does not change after being loaded with nano TiO2. However, its specific surface area (359.814 m^2·g^-1), pore volume (0.317 cm^3.g^-1) and average pore diameter (3.526 nm) increased; particularly the cumulative volume of pores was increased by 65.83%. In addition, the distribution range of the pores was wider than that of the bamboo charcoal. Combining the SEM of unmodified and modified poplar veneer, the results of X-ray photoelectron spectroscopy revealed that actually some TiOz compounds, i.e., 4.08%, are imbedded in the modified poplar veneer.