分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-08-18
摘要: We present a novel strategy for simultaneous doping of Cu ions into TiO2 nanocrystals and transforming amorphous anodic TiO2 nanotubes (TNTs) into anatase nanoparticle (NP) array film. Highly reactive colloidal Cu clusters derived by laser ablation in liquids were used as doping precursor, which can react with amorphous TiO2 nanotubes to form doped anatase NPs by dissolution and recrystallization processes. The Cu-doped TiO2 NPs (Cu-TNPs) film was characterized by X-ray diffraction, scanning and transmission electron microscopy and Raman spectroscopy. The Cu-TNPs show a rugby-like shape with exposed active {101}, {001} facets and the long-axis parallel to [001] lattice direction. The substitutional Cu2+ ions dopants in TiO2 nanocrystals caused the swelling of the crystalline unit cell, red shift of the absorption edge, and enhanced absorption in the visible-light region. The green and efficient doping design would facilliate the ongoing effort toward improving nanostructured TiO2 as a practical biosensor for glucose molecules.
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-09-19
摘要: Anatase porous TiO2 nanowires were synthesized via simple in situ hydrothermal treatment of the amorphous anodic TiO2 nanotubes in urea aqueous solution at 70 ºC. The morphology transformation process was also analyzed so that hydroxide induced dissolution-recrystallization mechanism was proposed. Due to the coarse surface and porous structure, the porous TiO2 nanowires possess a large surface area of 267.56 m2g-1, which is almost 4 times higher than that of amorphous anodic TiO2 nanotubes. The photocatalytic properties of the porous TiO2 nanowires towards MB, phenol and Rhodamine 6G were investigated. The porous TiO2 nanowires display better photocatalytic activity than that of TiO2 nanotubes or Degussa P25. The enhanced photocatalytic activity is attributed to the porous structure and the large specific surface area. Such porous TiO2 nanowires maybe considered as an ideal photocatalyst for the rapid photodegradation of organic pollutant in water. Furthermore, this facile, low-cost and environmentally friendly method is highly expected to innovate the design and fabrication of highly photoactive porous TiO2 nanowires, which have potential applications in photocatalysis and solar energy conversion.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Layered bismuth oxyhalide nanomaterials have received much more interest as promising photocatalysts because of their unique layered structures and high photocatalytic performance, which can be used as potential inorganic photosensitizers in tumor photodynamic therapy (PDT). In recent years, photocatalytic materials have been widely used in PDT and photothermal therapy (PTT) as inorganic photosensitizers. This investigation focuses on applying layered bismuth oxyhalide nanomaterials toward cancer PDT, an application that has never been reported so far. The results of our study indicate that the efficiency of UV- triggered PDT was highest when using BiOCl nanoplates followed by BiOCl nanosheets, and then TiO2. Of particular interest is the fact that layered BiOCl nanomaterials showed excellent PDT effects under low nanomaterial dose (20 μg mL−1) and low UV dose (2.2 mW cm−2 for 10 min) conditions, while TiO2 showed almost no therapeutic effect under the same parameters. BiOCl nanoplates and nanosheets have shown excellent performance and an extensive range of applications in PDT.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: We studied the carrier dynamics in a series of SnOx thin films using femtosecond transient absorption (TA) spectroscopy. The observed carrier relaxation was found to be strongly dependent on thin film stoichiometry. The TA spectra corresponding to free carriers, trapped carriers, and state filling were observed in the picosecond time region for SnO2, SnOx, and SnO film, respectively. The TA decay kinetics of all films were best fit with a tri-exponential decay model with fast (1 ps), medium ( 10 ps), and slow (ns) components. Our results revealed the carrier relaxation and recombination processes in SnOx thin films, identifying the critical role of stoichiometry in photo-induced phenomena.
分类: 动力与电气工程 >> 工程热物理学 提交时间: 2018-02-01 合作期刊: 《工程热物理学报》
摘要: 碱金属基吸收剂干法脱除燃煤烟气CO2技术日益受到学术界的关注,其中钠基吸收剂廉价易得,经济性好,但碳酸化反应活性低。本文将Na2CO3负载于活性氧化铝并掺杂TiO2改性,利用CO2吸收/解吸流化床试验装置、XRD、SEM和氮吸附仪研究钠基二氧化碳吸收剂的流化床反应特性。结果表明:TiO2对Na2CO3/Al2O3在流化床中的碳酸化反应特性提升明显,反应时间缩短、反应速度提高、CO2吸收量增加;碳酸化反应产物为NaHCO3和Na5H3(CO3)4;TiO2对再生反应影响甚微;且TiO2在反应前后性状稳定,无副产物生成。尽管如此,TiO2的掺杂量应控制在一定的范围内以避免吸收剂微观结构恶化而阻碍反应。
分类: 材料科学 >> 材料化学 提交时间: 2017-11-01
摘要: Doping additional ions into semiconductor is a potential strategy to modify the electronic structure of semiconductor materials. By using a highly reactive colloidal Cu clusters as doping precursor, we present here the successful doping of Cu ions into TiO2 nanocrystalline that simultaneously transformed from amorphous anodic TiO2 nanotubes during a dissolution and recrystallization process. The Cu-doped TiO2 nanoparticles (Cu-TNPs) film was characterized by X-ray diffraction, scanning and transmission electron microscopy and Raman spectroscopy. The Cu-TNPs show a rugby-like shape with exposed active {101}, {001} facets and the long-axis parallel to [001] lattice direction. The substitutional Cu2+ ions dopants in TiO2 nanocrystals caused the swelling of the crystalline unit cell. Such efficient doping design facilitate the improvement of nanostructured TiO2 as a potential biosensor for glucose molecules.
分类: 材料科学 >> 材料科学(综合) 提交时间: 2023-03-31 合作期刊: 《腐蚀科学与防护技术》
摘要: 概述了TiO2在腐蚀电化学中的应用以及在光生阴极保护方面的最新成果。分析了TiO2的不同制备方法和各自的特点。介绍了光生阴极保护实验的主要测试方法。列举了TiO2掺杂金属、非金属以及金属半导体在光生阴极保护领域的实验进展,并探讨了改性对TiO2光电转化性能的影响。展望了改进型TiO2在金属腐蚀防护领域的应用前景。
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: We reported the favorable cathode buffer layer based on a blend of ZnO nanoparticles (NPs) and TiO2 nanorods (NRs) applied to inverted solar cells. In addition to the high optical transmittance, the resultant blend film gave a relatively dense film with lower roughness than that of the respective single-component film. This improved the interface contact between the buffer layer and photoactive layer and therefore reduced the contact resistance and leakage current. Moreover, the combination of NRs and NPs increased the efficiency of electron transport and collection by providing both a direct path for electron transport from TiO2 NRs and a large contact area between ZnO NPs and the active layer. Consequently, both the short-circuit current density (Jsc) and fill factor (FF) in the device were improved, leading to an improvement of the device performance. The best power conversion efficiency (PCE) based on the blend film as the buffer layer reached 8.82%, which was preferable to those of a single ZnO NP film (7.76%) and a TiO2 NR-based device (7.66%). KEYWORDS: ZnO nanoparticles, TiO2 nanorods, blend film, cathode buffer layer, inverted solar cells
分类: 材料科学 >> 材料科学(综合) 提交时间: 2023-03-31 合作期刊: 《中国腐蚀与防护学报》
摘要: 通过原位化学氧化合成法制备了含不同比例纳米TiO2的聚苯胺/TiO2复合粉。以环氧树脂为成膜物质,采用共混的方法制备了聚苯胺/TiO2/环氧涂层,并通过正交实验优选出了力学性能最佳的涂层配方,耐化学品性测试验证了优选配方同时具有最佳的耐蚀性。最后分别考察了优选配方涂层在含S2-及Cl-盐溶液中的耐蚀性。结果表明:合成的复合粉颗粒为纳米级,聚苯胺和TiO2存在强烈相互作用;正交实验各因素对涂层力学性能影响的重要程度次序为:聚苯胺>TiO2>固化温度>溶剂的量>溶剂间比例;当聚苯胺与环氧树脂质量比为1∶100、TiO2与环氧树脂质量比为1∶100、固化温度为60℃、溶剂的量与环氧树脂质量比为5∶10、NMP与正丁醇的溶剂摩尔比为2∶1时,所得涂层力学性能及耐蚀性能最佳;涂层在65℃、3.5%(质量分数)NaCl溶液中浸泡72h后电化学阻抗出现极大值,在80℃、3%(质量分数)Na2S溶液中浸泡120h仍然具有良好的耐蚀性。
分类: 材料科学 >> 材料科学(综合) 提交时间: 2016-11-04 合作期刊: 《金属学报》
摘要: 通过对胶体晶体模板的反向复制, 制备了反点阵列孔径各异的Au/TiO2复合薄膜. 采用SEM, AFM, XRD, UV-Vis和四探针测试仪等手段对复合薄膜的结构和光催化性能进行了表征. 通过对胶体晶体模板和反点阵列几何模型的计算, 讨论了Au反点阵列在TiO2薄膜表面的覆盖面积与模板中微球粒径的关系. 结果表明: 反点阵列孔径对复合薄膜的光催化性能有显著影响. 孔径增大,使反点阵列的导电性能得以提高, 载流子的输运效率得到增强, 促使了光催化性能的提高; 同时, 孔径增大又造成光生电子向反点阵列迁徙过程中的复合几率加大, 反而使光催化性能降低. 两种作用共同导致了Au/TiO2复合薄膜的光催化性能随Au反点阵列孔径的增大出现先提高后降低的变化规律, 并在孔径为3.3 μm时达到最高.
提交时间: 2017-05-02
摘要: Template-free synthesis of TiO2 architectures with controlled morphology evolution has been developed through solvothermal reaction in 1,4-dioxane. By simply varying the molar ratio of the concentrated HCl over Titanium isopropoxide [TTIP] from 0 to 5.0,
分类: 材料科学 >> 材料科学(综合) 提交时间: 2023-03-18 合作期刊: 《材料研究学报》
摘要: 在草酸盐、硅酸盐和磷酸盐电解液体系中, 在钛合金Ti-6Al-4V(TC4)表面制备阳极氧化TiO2膜层, 研究了TiO2膜层的表面显微结构、化学组成和生物活性。在室温用恒压阳极氧化法制备TC4 表面阳极氧化TiO2膜, 以TC4 为阳极, 不锈钢为阴极, 电解液组成为: 20 g/L 的Na2C2O4、10 g/L 的Na2SiO3·9H2O、9.25 g/L 的NaH2PO4和2 g/L 的NaOH, 阳极氧化电压为10-120 V, 氧化时间50 min, 电源频率200 Hz。用XRD、AFM、SEM及XPS等手段分别测量了膜层的物相、三维形貌、氧化膜层表面的显微结构及化学组成。结果表明: 氧化电压对TiO2膜层的物相组成基本没有影响, 氧化膜层呈非晶态TiO2。当氧化电压为30 V时, TiO2膜层表面由孔径1.3 μm左右的孔和凸起颗粒组成的粗糙结构, 随着氧化电压增加表面凸起颗粒逐渐减少, 粗糙度降低, 当氧化电压为100 V时场致溶解的作用使TiO2膜层表面凸起颗粒不明显, TiO2膜层表面的粗糙度低于TC4 基体, 表面孔径为240 nm。TC4 阳极氧化TiO2膜层表面的微纳米结构和大量的羟基—OH, 有利于提高TiO2膜层的生物活性和骨生长特性。
分类: 材料科学 >> 材料科学(综合) 提交时间: 2016-11-08 合作期刊: 《腐蚀科学与防护技术》
摘要: 研究了含量分别为0%、1%、3%和5%的硅烷偶联剂改性前后的纳米TiO2对涂覆在45#碳钢上的聚氨酯涂层耐腐蚀性能的影响。场发射电镜(FESEM)测试结果表明,未改性纳米TiO2在涂层中以团聚体的状态存在,经过硅烷偶联剂KH-570改性后的纳米TiO2在涂层中均匀分散,其中含量为3%的涂层结构最为致密。采用电化学阻抗(EIS)技术研究了纳米TiO2/聚氨酯复合涂层在3.5%NaCl溶液中浸泡不同时间的阻抗行为,实验结果表明添加硅烷偶联剂改性纳米TiO2可明显提高聚氨酯涂层的耐腐蚀性,其中含3%改性纳米TiO2的涂层在浸泡过程中,始终呈现一个时间常数特征,在浸泡至2880h后,涂层电阻仍然为2.6×108 Ω·cm2,明显高于其他组分的涂层电阻,表明该涂层具有最好的耐腐蚀性。
分类: 材料科学 >> 材料科学(综合) 提交时间: 2023-03-18 合作期刊: 《材料研究学报》
摘要: 以三乙胺为氮源, 采用层层自组装和高温煅烧方法制备球形形貌良好的N掺杂TiO2中空介孔微球(N-THS), 使用XPS、XRD、UV-Vis DRS等手段研究了煅烧温度对其结构和光催化性能的影响。结果表明, N进入TiO2晶格内取代了部分O元素并改变了晶格中Ti 和O的化学状态; 在400-600℃煅烧所得TiO2呈现锐钛矿相结构, 将煅烧温度提高到700℃则出现向金红石相的转变, 且TiO2的晶粒尺寸随着煅烧温度的提高而增大。N-THS在可见光区具有明显的吸收性能, 吸收光谱带也发生了明显红移, 对MO溶液均具有较好的降解效率; 而随着煅烧温度的降低, 可见光区吸收相应增强, 降解效率提高, 在400℃锻烧的N-THS经光照射80 min后其降解率达到93.5%。
分类: 材料科学 >> 材料科学(综合) 提交时间: 2023-03-18 合作期刊: 《材料研究学报》
摘要: 用旋涂热分解前驱H2PtCl6·6H2O溶液制备Pt/FTO对电极, 研究了旋涂退火次数对Pt/FTO对电极的载铂量、透光率和组装的染料敏化太阳能电池光电性能的影响。结果表明, 用5 次旋涂退火的对电极组装的电池具有最佳的能量转换效率(6.78%), 高于用传统的磁控溅射对电极组装的电池。基于在最佳光电性能情况下对电极的旋涂次数和载Pt 量, 进一步优化H2PtCl6·6H2O前驱液的浓度和使用体积。采用一步滴涂退火处理, 得到了具有高透光性、低载Pt 量和高的组装电池效率的Pt/FTO对电极。用此一步法制备的Pt/FTO对电极, 组装成的电池能量转换效率达到6.92%。