ANALYTICAL CHEMISTRY
·
2009
·
IF 5.712
Qingqing Guo,Shujun Ji,Qiaoli Yue,Lei Wang,Jifeng Liu,Jianbo Jia
Antioxidant amperometric sensors based on iron-containing complexes and protein modified electrodes were developed. Indium tin oxide glass was printed with TiO2 nanoparticles, onto which iron-containing compounds and protein were adsorbed. When applied with negative potentials, the dissolved oxygen is reduced to H2O2 at the electrode surface, and the H2O2 generated in situ oxidizes FeII to FeIII, and then electrochemical reduction of FeIII therefore gives rise to a catalytic current. In the presence of antioxidants, H2O2 was scavenged, the catalytic current was reduced, and the decreased current signal was proportional to the quantity of existing antioxidants. A kinetic model was proposed to quantify the H2O2 scavenging capacities of the antioxidants. With the use of the sensor developed here, antioxidant measurements can be done quite simply: put the sensor into the sample solutions (in aerobic atmosphere), perform a cathodic polarization scan, and then read the antioxidant activity values. The present work can be complementary to the previous studies of antioxidant sensor techniques based on OH radicals and superoxide ions scavenging methods, but the sensor developed here is much easier to fabricate and use.
研究领域:
电分析化学
·
生物传感器
·
纳米材料
·
抗氧化分析
·
环境监测
·
食品科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2012
·
IF 3.461
Weishuang Ni,Songping Wu,Qun Ren
Surface modification of TiO 2 nanoparticles with 3-methacrylic acyloxy propyl trimethoxysilane (KH570) was carried out in the liquid phase. As additives, the modified TiO 2 nanoparticles were employed as charge control agents (CCAs) in the toner. The hydroxyl groups on the surface of TiO 2 nanoparticles can interact with methoxy groups of KH570 and an organic coating layer formed. The Ti O Si bond was testified by Fourier transform infrared spectra (FTIR). Through transmission electron micrograph (TEM) observation, it was found that the organic coating layer was about ∼3.1 nm and the dispersibility of the modified TiO 2 nanoparticles were obviously improved. Static water contact angle was used to investigate the wettability of the modified TiO 2 surfaces. The results indicated that the hydrophobicity of the modified TiO 2 nanoparticle surfaces could be effectively improved as the amount of the coated KH570 increased. The specific surface area (SSA) of the modified TiO 2 was determined by Brunauer–Emmet–Teller (BET) method. Surface morphology of the modified toner and the toner charge were investigated by scanning electron microscopy (SEM) and electrometer, respectively. The modified toner showed smoother surface and the toner charge was adjusted by the modified TiO 2 nanoparticles. The charge-to-mass ratio (Q/M) values shifted to the negative direction, for example −13.25 μC/g, with an increasing coated KH570, probably due to the OH groups existing on the surface of TiO 2 .
研究领域:
材料科学
·
纳米技术
·
表面化学
·
静电成像
·
聚合物复合材料
✓ 已验证
DOI
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2022
·
IF 9.93
Jihong Jiang,Xiaobin Dong,Han Wang,Fengjuan Wang,Yali Li,Zeyu Lu
This study investigated the impact of natural sand supported nano-TiO 2 hydrosol (TiO 2 @Sand) on the mechanical and photocatalytic performance of cement mortar and the underlying mechanisms. The incorporation of TiO 2 @Sand in cement mortar (TiO 2 was 0.6 wt% of cement) improved 28-day compressive strength by 67% compared with the one without nano-TiO 2 . Various beneficial changes towards improved mechanical strength were also observed in TiO 2 @Sand cement mortar: reduced total porosity by 35%, densified interfacial transition zone (ITZ) microstructure, enhanced modulus of ITZ by 54%, reduced ITZ thickness by 40% and improved dispersion of TiO 2 . The degradation efficiency of Rhodamine B and NO by TiO 2 @Sand reinforced mortar was 40% and 25% higher than cement matrix with conventionally dispersed nano-TiO 2 powder, respectively. The significantly enhanced photocatalytic activity of the TiO 2 @Sand mortar was attributed to the expanded light absorption range, the reduced recombination of electron-hole pairs of TiO 2 @Sand, and the better dispersion of nano-TiO 2 in cement matrix. These results demonstrated the promising potential of using TiO 2 @Sand in cement mortar to deliver significant enhancement of both mechanical strength and photocatalytic activity.
研究领域:
材料科学
·
土木工程
·
光催化
·
建筑材料中的纳米材料
✓ 已验证
DOI
高影响因子
SYNTHETIC METALS
·
2013
·
IF 2.109
Yakupjan Osman,Ruxangul Jamal,Adalet Rahman,Feng Xu,Ahmat Ali,Tursun Abdiryim
The poly(3,4-propylenedioxythiophene)/TiO 2 nanocomposites (PProDOT/TiO 2 ) were synthesized by using mechanochemical solvent free and common chemical solution method. The structure and physicochemical properties of the PProDOT/TiO 2 nanocomposites were compared with that of pure PProDOT. The results of FTIR and UV–vis spectra showed that the PProDOT/TiO 2 nanocomposites and pure PProDOT prepared by mechanochemical method displayed higher oxidation degree and conjugation length than the samples prepared by chemical method. The XRD and morphological analysis indicated that the TiO 2 had no effect on the crystallinity of PProDOT from both methods, and the TiO 2 well embedded in polymer matrix. Moreover, the results of the electrochemical performances showed that the PProDOT/TiO 2 nanocomposites and pure PProDOT synthesized by mechanochemical method had higher electrochemical activity than the samples from chemical method. The highest specific capacitance of 219 Fg −1 is obtained in the case of the mechanochemically synthesized PProDOT/TiO 2 nanocomposites.
研究领域:
材料科学
·
纳米复合材料
·
高分子化学
·
电化学
·
绿色合成
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2012
·
IF 2.307
Shiguo Chen,Yujuan Guo,Shaojun Chen,Zaochuan Ge,Haipeng Yang,Jiaoning Tang
Incorporation of nanoparticles is becoming a new strategy for improving antibacterial activity . In this paper, Copper (Cu)/titanium dioxide (TiO 2 ) (CTD) nanocomposite was easily prepared by photocatalytic reduction, and its structure as well as antibacterial activity in the absence of light was investigated in detail. The results show that the CTD nanocomposite exhibits good antibacterial activity even in the absence of light. The minimal inhibition concentration against Escherichia coli and Staphylococcus aureus is 21.4 μg/mL and 14.3 μg/mL, respectively, which are much lower than that of pure silver, Cu and TiO 2 nanoparticles . In addition, the enhanced antibacterial effect of the CTD nanocomposite may be explained by synergistic antibacterial effect.
研究领域:
材料科学
·
纳米技术
·
抗菌研究
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Cheng Zuo,Xishi Tai,Qian Su,Zaiyong Jiang,Qingjie Guo
In the field of photocatalysis , the loaded photocatalyst possesses the advantages of controllable morphology, uniform preparation, low cost, and easy recovery. It can effectively avoid the secondary pollution caused by the powder catalyst and is considered a potential substitute for the powder photocatalyst. In this work, TiO 2 and Cu 7 S 4 hybrid materials with oxygen vacancies (OV) grown in situ on copper mesh (CM) were prepared by anion exchange and hydrothermal reaction . The characterization results showed that the concentration of oxygen vacancies in TiO 2 increased significantly after calcination . Under the simulated visible light , the liquid film reaction was adopted. The yield of NH 3 synthesized by OV–TiO 2 @Cu 7 S 4 /CM photocatalyst was 133.42 μmol cm −2 h −1 , 5.2 and 2.2 times that of pure TiO 2 and Cu 7 S 4 , respectively. The enhanced photocatalytic performance is attributed to the synergistic effect between the interfacial electric field of the S-scheme heterostructure and the abundant oxygen vacancies , which induces the efficient separation and migration of carriers. The cycle experiment showed that OV–TiO 2 @Cu 7 S 4 /CM heterojunction has excellent stability in photocatalytic nitrogen fixation . This work provides insight into the design of S-scheme photocatalysts with rich surface defects for green and efficient reduction of N 2 .
研究领域:
光催化
·
材料科学
·
环境科学
·
纳米技术
·
能量转换
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Ya-Nan Li,Zhao-Yang Chen,Min-Qiang Wang,Long-zhen Zhang,Shu-Juan Bao
A porous g-C 3 N 4 /TiO 2 with hierarchical heterostructure has been successfully fabricated through a in situ assembling of small needle-like TiO 2 on the surface of ultrathin g-C 3 N 4 sheets. The ultrathin g-C 3 N 4 sheets with carbon vacancies and rich hydroxyl groups were found to facilitate the nucleation and in situ growth of TiO 2 and also to modulate the surface chemical activity of the g-C 3 N 4 /TiO 2 hierarchical heterostructure. The as-designed photocatalytic heterojunction degraded Acid Orange with 82% efficiency after 10 min under simulated solar light, and possessed excellent cycle stability. Relative physical characterizations and photochemical experiments reveal that engineering the interface/surface of g-C 3 N 4 plays a vital role in effectively constructing heterostructures of g-C 3 N 4 /TiO 2 , thus realizing efficient photoinduced electron-hole separation during photocatalytic process.
研究领域:
材料科学
·
环境催化
·
纳米技术
·
光催化
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Yinyan Gong,Chengxin Fu,Lv Ting,Jingru Chenu,Qinger Zhao,Can Li
Aiming to improve the photocatalytic activity, boron and tantalum co-doped TiO 2 nanocrystals were prepared by a sol–gel method. Pure and doped titania samples were characterized by X-ray diffraction (XRD) measurements, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy. The results revealed that all the samples have highly crystalline anatase structure, and no any other second phase was observed. It is found that the incorporation of dopants inhibits the growth of TiO 2 nanocrystal. Moreover, XPS observations showed that Ta are in the form of Ta 5+ while the majority of B species are present at interstitial sites. Finally, photocatalytic activities of all the samples were evaluated by degradation of methylene blue (MB) solutions under simulated solar light irradiation. Ta-doped and (B, Ta)-codoped catalysts exhibit enhanced photocatalytic activities in comparison with pure TiO 2 , with the codoped sample exhibiting the best photodegradation performance. This indicates that B and Ta co-doping is an effective way to improve photocatalytic performance of TiO 2 . The catalytic activity of B-doped TiO 2 becomes slightly worse than pure TiO 2 nanocrystals, which is plausible due to increased charge carrier recombination centers induced by incorporation of boron species.
研究领域:
材料科学
·
光催化
·
纳米材料
·
环境化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Zhenyu Zhu,Feng Zhou,Su Zhan,Yu Tian,Qiuchen He
Marine fouling organisms attachment can bring serious damage to ships and marine facilities. Thus, we modified the hydrophobic fluorocarbon resin coating (PEVE) which was widely used in marine hulls. In this study, graphene/TiO 2 nanocomposite photocatalysts have been taken as the raw material of the modification to prepare the composite coatings with anti-fouling performance through a sample method. The results of our experiment demonstrate that when the mass ratio of rGO to TiO 2 is 1:100, the composite coating exhibits the best antibacterial property. This coating could kill the vast majority of the bacteria which attached to its surface after one hour of exposure to ultraviolet light, and this sterilization performance is much higher than pure PEVE and TiO 2 /PEVE coatings. In this composite system, graphene plays an important role in enhancing the coatings performance. For one thing, the heterojunction formed by graphene and TiO 2 can effectively increase the hydroxyl radical yields of TiO 2 . For another, the conjugated structure of graphene can effectively reduce the phenomenon of hydrophobicity reduction which is caused by the addition of TiO 2 and then decrease the risk of hull corrosion availably.
研究领域:
材料科学
·
海洋工程
·
环境化学
·
光催化
·
表面涂层
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·Vol. 45
·期 8
·10845-10851
·
IF 3.45
Yuhan Yao,Ju Rong,Jing Feng,Yannan Zhang,Xiao Wang,Xiaohua Yu,Zhaolin Zhan
The modification of TiO 2 is a vigorous and challenging research field. In the present study, TiO 2 /CuO composite nanofibers , designed by considering the thermodynamics of nanocrystals , have been synthesized by an electrospinning and hydrothermal method . The results showed that the grain growth of uniform and highly active CuO was driven by the surface drag force of TiO 2 nanofibers. TiO 2 /CuO showed an alternating current impedance as low as 2.874 Ω, and the Li + diffusion rate was increased tenfold compared to that of bare TiO 2 nanofibers. Equally importantly, the electron diffusion kinetics was also explored, which revealed that the band gap was reduced by 1.14 eV compared to that for bare TiO 2 nanofibers. In addition, TiO 2 /CuO exhibited satisfactory stability and electrochemical performance. Its initial discharge capacity was 540 mAh·g −1 , and that after discharge over 400 cycles at 0.1 C was 174 mAh·g −1 . The design method may be more broadly applied to various nanostructured TiO 2 materials.
研究领域:
材料科学
·
纳米技术
·
电化学
·
储能
✓ 已验证
DOI
高影响因子
Metals
·
2019
·Vol. 9
·期 2
·171
·
IF 2.259
Zhengyu Cai,Hui Kong
TiO2nanoparticles and Mg alloy were added to molten steel in sequence to investigate the inclusion and microstructure characteristics. Compared with a non-treated sample, these additives resulted in the formation of Ti–Mg-bearing inclusions, which proves that the additives were valid. The size evolution from nanometer-scale TiO2to micrometer-scale oxides hints at the agglomeration and growth of the TiO2nanoparticles, which is due to the possible formation of a liquid-capillary force, the decomposition reaction of TiO2, and the higher Gibbs free energy of the nanoparticle. Furthermore, the statistical analysis of the oxides indicated that with the addition of the TiO2nanoparticles and Mg alloy, the oxides were refined and their density was higher. Few pure MnS were observed in the treated sample. This is due to the fact that most oxides separated out in the liquid region at 1873 K based on the oxide composition and the calculated Al2O3–Ti3O5–MgO phase diagram. Thus, MnS preferred to segregate on them during solidification. After etching, it was found that the Ti–Mg-bearing oxide can induce the nucleation of intragranular acicular ferrites. The appearance of these acicular ferrites was not observed in the non-treated sample. This comparison indicates the effectiveness of the external adding method in oxide metallurgy.
研究领域:
材料科学
·
冶金学
·
纳米材料
·
相变
·
钢铁加工
✓ 已验证
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 6
·896
·
IF 2.972
Zhu Zhu,Ye Zhang,Yibo Zhang,Yanli Shang,Xueji Zhang,Yongqiang Wen
Ethylene causes faster deterioration of perishable crops during postharvest transportation and storage. The present study aimed to develop TiO2-coated nanofibers with efficient photocatalytic activities to enhance the degradation of fruit-emitted ethylene. The consecutive electrospinning of polyacrylonitrile (PAN) and TiO2deposition was successfully performed to produce PAN@TiO2nanofibers. The scanning electron microscopy results indicate the uniform distribution of TiO2nanoparticles on the surface of the PAN nanofiber. The PAN@TiO2composite nanofibers exhibited enhanced photocatalytic activity for ethylene degradation under low-intensity UV light irradiation. Furthermore, a tomato fruit-ripening test confirmed the effectiveness of the PAN@TiO2nanofibers. The PAN@TiO2nanofibers exhibited effective ethylene degradation and slowed the color shift and softening of the tomatoes during storage. The results suggest great potential for use of the PAN@TiO2composite nanofibers as ethylene scavenging packaging material for fresh fruits and vegetables.
研究领域:
食品科学与技术
·
材料科学
·
纳米技术
·
采后生物学
·
环境催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）