Fabrication, Modification and Photoelectrocatalytic Activity of Hybrid TiO2 Nanomaterials

环境污染和能源短缺是21世纪人类面临和亟待解决的重大问题，已成为我国推行全面协调可持续发展的重要制约因素。国际社会越来越多地关注如何利用绿色技术解决环境污染这一世界难题。纳米半导体光催化以其在室温下可直接利用太阳光驱动深度降解反应的独特优点成为当今国内外竞相研究开发并用于环境污染治理的一种重要技术，利用廉价太阳能实现对持久性有机污染物的有效降解是一种极具前途的环境污染深度净化技术，已引起全世界相关领域研究者的广泛重视。纳米TiO2因其具有强氧化活性、良好的光电转换性能、高化学稳定、无毒、廉价等特点，被认为是一种极具发展前景的纳米光催化剂。尽管TiO2光催化技术近几十年已取得长足进步，但仍存在诸...Environmental pollution and energy shortage are two major issues to be solved in the 21st century, becoming the key constraints to implement comprehensive, coordinated and sustainable development in the world. The implementation of green technologies to alleviate the environmental pollution remains a grand challenge and has received increasingly global attention. Due to the unique ability of direc...学位：理学博士院系专业：化学化工学院_物理化学学号：2052012015352

Fabrication of a Spongelike Nanostructured TiO_2 Film and Its Photocatalytic Activity

采用电化学阳极氧化法在钛表面构筑了海绵状纳米结构TIO2膜.应用扫描电子显微镜(SEM)和X射线衍射(Xrd)对膜层的形貌和晶型进行了分析和表征,考察了阳极氧化时间对膜层厚度的影响,并通过海绵状纳米结构TIO2膜对甲基橙的光催化降解研究了膜层厚度与光催化活性的关系.结果表明,海绵状纳米结构TIO2膜对甲基橙具有光催化降解作用,而且随着膜层厚度的增加,光催化降解速率显著增大,厚度为2.2μM的海绵状纳米结构TIO2膜对甲基橙的光催化降解速率是厚度为480nM的6.4倍.A spongelike nanostructured titanium dioxide(TiO2) film was fabricated on a titanium substrate by electrochemical anodic oxidation.Scanning electron microscopy(SEM) and X-ray diffraction(XRD) experiments were performed to characterize the morphology and crystalline phase of the spongelike nanostructured TiO2 films.The effect of anodizing time on the thickness of the layers was examined.The relationship between the thickness of the spongelike nanostructured TiO2 film and its photocatalytic activity was investigated by the degradation of methyl orange solution.Results showed that the spongelike nanostructured TiO2 film had a high photocatalytic activity.The photocatalytic degradation rate of a methyl orange solution increased with the film thickness.The photocatalytic degradation rate by the spongelike nanostructured TiO2 film with a thickness of 2.2 μm was 6.4 times as large as that by the spongelike nanostructured TiO2 film with a thickness of 480 nm.福建省自然科学基金(U0750015);福建省科技计划重点课题(2007H0031);厦门市科技计划(3502Z20073004);国家基础科学人才培养基金(J0630429)资助项目---

Preparation and Visible Light Photocatalytic Activity of Fe-N Codoped TiO2 Nanotube Arrays

Corresponding author. Email: [email protected]; Tel: +86-10-2184655[中文文摘]应用电化学阳极氧化法结合浸渍和退火后处理制备了Fe和N共掺杂的TiO2纳米管阵列光催化剂,并用场发射扫描电镜(FESEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和俄歇电子能谱(AES)仪对其进行了表征.结果表明,Fe、N共掺杂对TiO2纳米管阵列的形貌和结构没有明显影响,Fe和N均掺入了TiO2晶格.紫外-可见(UV-Vis)漫反射光谱显示Fe和N共掺杂TiO2纳米管阵列的吸收带边较纯TiO2纳米管阵列和单一掺杂TiO2纳米管阵列红移,可见光吸收增强.以可见光催化降解罗丹明B(RhB)考察了材料的光催化活性,Fe和N共掺杂TiO2纳米管阵列对RhB的降解速率较纯TiO2纳米管阵列和单一掺杂TiO2纳米管阵列明显提高,证明了Fe、N共掺杂产生的协同效应提高了TiO2纳米管阵列在可见光照射下的光催化活性. [英文文摘]Fe-N codoped TiO2 nanotube arrays were fabricated by anodization of Ti, followed by wet immersion and annealing post-treatment. The doped TiO2 nanotube array photocatalysts were characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). The results indicated that Fe and N dopants had almost no effect on the morphology and structure of TiO2 nanotube arrays, and that Fe and N were doped into the TiO2 lattice. UV-Vis diffuse reflectance spectra showed that the absorption band edge of Fe-N codoped TiO2 nanotube arrays exhibited a red shift compared with that of pure TiO2 nanotube arrays and Fe- or N-doped TiO2 nanotube arrays. The photocatalytic activity of Fe-N codoped TiO2 nanotube arrays was evaluated by their ability to degrade rhodamine B under visible light irradiation. The degradation rate of rhodamine B over Fe-N codoped TiO2 nanotube arrays was obviously higher than that over pure TiO2 nanotube arrays and Fe- or N-doped TiO2 nanotube arrays, which is attributed to the synergistic effect of the Fe and N codopants.国家自然科学基金(51072170,21021002);福建省自然科学基金(2011J01057);国家基础科学人才培养基金(J1030415)资助项

Preparation and Visible Light Photocatalytic Activity of Fe-N Codoped TiO_2 Nanotube Arrays

应用电化学阳极氧化法结合浸渍和退火后处理制备了fE和n共掺杂的TIO2纳米管阵列光催化剂,并用场发射扫描电镜(fESEM)、X射线衍射(Xrd)、X射线光电子能谱(XPS)和俄歇电子能谱(AES)仪对其进行了表征.结果表明,fE、n共掺杂对TIO2纳米管阵列的形貌和结构没有明显影响,fE和n均掺入了TIO2晶格.紫外-可见(uV-VIS)漫反射光谱显示fE和n共掺杂TIO2纳米管阵列的吸收带边较纯TIO2纳米管阵列和单一掺杂TIO2纳米管阵列红移,可见光吸收增强.以可见光催化降解罗丹明b(rHb)考察了材料的光催化活性,fE和n共掺杂TIO2纳米管阵列对rHb的降解速率较纯TIO2纳米管阵列和单一掺杂TIO2纳米管阵列明显提高,证明了fE、n共掺杂产生的协同效应提高了TIO2纳米管阵列在可见光照射下的光催化活性.Fe-N codoped TiO 2 nanotube arrays were fabricated by anodization of Ti,followed by wet immersion and annealing post-treatment.The doped TiO 2 nanotube array photocatalysts were characterized by field-emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and Auger electron spectroscopy(AES).The results indicated that Fe and N dopants had almost no effect on the morphology and structure of TiO 2 nanotube arrays,and that Fe and N were doped into the TiO 2 lattice.UV-Vis diffuse reflectance spectra showed that the absorption band edge of Fe-N codoped TiO 2 nanotube arrays exhibited a red shift compared with that of pure TiO 2 nanotube arrays and Fe-or N-doped TiO 2 nanotube arrays.The photocatalytic activity of Fe-N codoped TiO 2 nanotube arrays was evaluated by their ability to degrade rhodamine B under visible light irradiation.The degradation rate of rhodamine B over Fe-N codoped TiO 2 nanotube arrays was obviously higher than that over pure TiO 2 nanotube arrays and Fe-or N-doped TiO 2 nanotube arrays,which is attributed to the synergistic effect of the Fe and N codopants.国家自然科学基金(51072170;21021002);福建省自然科学基金(2011J01057);国家基础科学人才培养基金(J1030415)资助项目---

Progress on modification and application of Ti based TiO_2 nanotube arrays in photocatalytic degradation organic pollutants

对近年发展的TI基TIO2纳米管阵列改性的方法及其在光催化降解有机污染物方面应用的研究进展进行了全面的综述,分析了当前存在的问题,并对TIO2纳米管阵列材料研究的发展趋势进行了展望.This paper reviews the recent research achievements of Ti-based TiO2 nanotube arrays on the modification and the application in the photocatalytic degradation of pollutants.The existing problems and further prospects in this field are also proposed.国家自然科学基金(21021002;51072170);国家基础科学人才培养基金(J1030415)资

Fabrication of a Spongelike Nanostructured TiO2 Film and Its Photocatalytic Activity

A spongelike nanostructured titanium dioxide (TiO2) film was fabricated on a titanium substrate by electrochemical anodic oxidation. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) experiments were performed to characterize the morphology and crystalline phase of the spongelike nanostructured TiO2 films. The effect of anodizing time on the thickness of the layers was examined. The relationship between the thickness of the spongelike nanostructured TiO2 film and its photocatalytic activity was investigated by the degradation of methyl orange solution. Results showed that the spongelike nanostructured TiO2 film had a high photocatalytic activity. The photocatalytic degradation rate of a methyl orange solution increased with the film thickness. The photocatalytic degradation rate by the spongelike nanostructured TiO2 film with a thickness of 2.2 mu m was 64 times as large as that by the spongelike nanostructured TiO2 film with a thickness of 480 nm.Natural Science Foundation of Fujian Province, China [U0750015]; Technical Programs of Fujian Provinc

Preparation of Co1-xS-MnS@CNTs/CNFs for Electrocatalytic Oxygen Reduction Reaction

氧还原反应是燃料电池中重要的阴极反应,但由于动力学迟缓等问题导致其效率低。碳基材料具有导电性高、稳定性好、比表面积大等优点,常被应用于电催化氧还原反应。然而其在电催化氧还原反应中效率较低,对碳基材料进行Co、Mn掺杂有望提高其氧还原效率。本文采用静电纺丝技术制备出含有Co,Mn双金属的碳纳米纤维,经热解和硫化后碳纳米纤维上形成许多包裹Co1-xS和MnS纳米颗粒的碳纳米管（记为Co1-xS-MnS@CNTs/CNFs）,垂直生长在碳纳米纤维表面。通过X射线衍射、场发射扫描电子显微镜、高分辨透射电子显微镜、X射线光电子能谱对Co1-xS-MnS@CNTs/CNFs的形貌、结构和组成进行表征,发现仅在Co1-xS和MnS同时存在的情况下碳纳米纤维表面才能生长碳纳米管。小颗粒的MnS为碳纳米管的生成提供成核位点,大颗粒的Co1-xS促进碳纳米管生长,最终形成Co1-xS-MnS@CNTs/CNFs。碳纳米管的形成不仅在金属颗粒表面形成一道屏障,防止其聚集、溶解,而且提高了碳纳米纤维的导电性,使其电催化性能及稳定性得到很大提升。电催化测试证明,Co1-xS-MnS@CNTs/CNFs相较于不含金属的碳纳米纤维（CNFs）及含单金属的硫化锰碳纳米纤维（MnS/CNFs）或硫化钴碳纳米纤维（Co1-xS/CNFs）具有更优异的电催化氧还原（ORR）性能,且在氧还原反应过程中表现出高效的四电子转移。其甲醇耐受性及长期稳定性显著优于商业Pt/C电催化剂。As an important cathode reaction in fuel cells and metal-air batteries, oxygen reduction reaction (ORR) is a complex reaction of slow kinetics, which severely limits performances of fuel cells and metal-air batteries. Therefore, it is of key importance to find an efficient and stable electrocatalyst to promote ORR. Carbon-based materials, which possess high conductivity, good stability and large specific surface area, are usually used in electrocatalytic ORR. However, pure carbon-based materials exhibit low efficiency. Coupling carbon-based materials with manganese (Mn) and cobalt (Co) transition metals containing 3d orbitals is an effective way to improve electrocatalytic performance. Herein, carbon nanofibers containing Co and Mn elements were crafted via an electrospinning technique, using polyacrylonitrile, cobalt acetate, manganese acetate and F127 as the carbon, cobalt, and manganese sources and pore-forming agent, respectively. After vulcanizing and carbonizing the pre-oxidized electrospun samples, carbon nanofibers coated with carbon-nanotubes-wrapping Co1-xS and MnS nanoparticles (denoted as Co1-xS-MnS@CNTs/CNFs) were formed. A series of measurements were carried out to characterize the morphology and structure of samples by employing X-ray diffraction technique, field emission scanning electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. It is found that carbon nanotubes grew on the surface of carbon nanofibers when Co1-xS and MnS nanoparticles co-existed. During the growth of Co1-xS-MnS@CNTs/CNFs, MnS particles served as nucleation sites for the formation of carbon nanotubes and Co1-xS particles promoted the growth of carbon nanotubes. In addition, the as-prepared samples were composed of Co, Mn, N, C and S elements. More specifically, nanofibers were composed of C and N elements. S element functioned as the sulfur source for both Co1-xS and MnS nanoparticles, as well as the dopant of nanofibers. The dopings of N and S into carbon nanofibers could promote the oxygen adsorption, facilitating the oxygen breaking of the O-O bond and thus improving the ORR activity. Moreover, it is demonstrated that carbon nanotubes wrapping Co1-xS and MnS nanoparticles play as barriers, preventing Co1-xS and MnS nanoparticles from aggregation and dissolution. Electrocatalytic test displays that Co1-xS-MnS@CNTs/CNFs exhibited higher electrocatalytic activity toward ORR compared with CNFs, MnS/CNFs and Co1-xS/CNFs, revealing an efficient overall four-electron transfer process. The onset potential of Co1-xS-MnS@CNTs/CNFs was slightly negative, while the ORR current density was higher compared with commercial Pt/C (20wt.%). It is worth noting that Co1-xS-MnS@CNTs/CNFs possessed better stability and higher methanol tolerance than commercial Pt/C in alkaline media. It is observed that the current of Co1-xS-MnS@CNTs/CNFs dropped slightly after the test running for 20000 s, while that of commercial Pt/C lowered significantly. This research provides a simple yet effective method to prepare non-noble metal electrocatalysts with excellent electrocatalytic performance, which presents an appealing strategy for efficient energy storage and conversion.国家自然科学基金项目(21905317);中国科协青年人才托举项目资助通讯作者:王梦晔E-mail:[email protected]:Meng-YeWangE-mail:[email protected]中山大学光电子材料与技术国家重点实验室,广东 广州 510275State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, Guangdong,Chin

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^