杂化Cu2O/Cu纳米粒子的水相合成及强化光降解甲基橙的催化活性研究

为了优化Cu2O纳米粒子的光催化性能,论文以抗坏血酸作为还原剂、聚乙烯吡咯烷酮为表面活性剂采用水相合成的方法通过调控反应温度制备出杂化Cu2O/Cu纳米粒子。利用SEM、XRD和N2吸附技术对Cu2O/Cu纳米粒子的形貌特征和结构性能进行表征。同时,也研究Cu2O/Cu纳米粒子催化降解甲基橙(MO)的效果和降解反应动力学。实验结果表明,制备的杂化Cu2O/Cu纳米粒子为“鹅卵石”形状,粒径尺寸范围在20至40nm之间,与纯Cu2O粒子相比相比,杂化Cu2O/Cu粒子具有尺寸小、比表面积大的特点。由于杂化材料中引入了Cu纳米粒子,促进了Cu和Cu2O和之间的界面电荷转移,使得Cu2O/Cu纳米粒子展现更优异的催化性能。Cu2O/Cu催化降解MO的反应符合一级动力学反应模型。经过四次循环使用后,杂化Cu2O/Cu仍然能表现出良好的催化活性。     

青铜制品的腐蚀行为研究

通过模拟闭塞电池实验对青铜制品表面局部腐蚀过程进行了研究。结果表明,合金元素选择性腐蚀和溶解速度顺序均为铅、铜、锡。随着腐蚀时间延长,腐蚀产物起初为Cu Cl和少量Cu2O,然后产生Cu Cl、Cu2O和少量Cu2Cl(OH)3、Cu4SO4(OH)6;腐蚀产物呈层状,由内至外依次为Cu Cl、Cu Cl及Cu2O、Cu4SO4(OH)6H2O。     

杂化Cu_2O/Cu纳米粒子的水相合成及强化光降解甲基橙的催化活性研究（英文）

为了优化Cu_2O纳米粒子的光催化性能,以抗坏血酸作为还原剂、聚乙烯吡咯烷酮为表面活性剂,采用水相合成的方法通过调控反应温度制备出杂化Cu_2O/Cu纳米粒子。利用SEM、XRD和N_2吸附技术对Cu_2O/Cu纳米粒子的形貌特征和结构性能进行表征。同时,也研究Cu_2O/Cu纳米粒子催化降解甲基橙(MO)的效果和降解反应动力学。结果表明,制备的杂化Cu_2O/Cu纳米粒子为"鹅卵石"形状,粒径尺寸范围在20~40 nm之间,与纯Cu_2O粒子相比,杂化Cu_2O/Cu粒子具有尺寸小、比表面积大的特点。由于杂化材料中引入了Cu纳米粒子,促进了Cu和Cu_2O之间的界面电荷转移,使得Cu_2O/Cu纳米粒子展现更优异的催化性能。Cu_2O/Cu催化降解MO的反应符合一级动力学反应模型。经过4次循环使用后,杂化Cu_2O/Cu仍然能表现出良好的催化活性。     

铜在含氯薄液膜和杂色曲霉作用下的腐蚀行为

目的 研究纯铜在含氯液膜和霉菌共同作用下的腐蚀行为与机理。方法 将海南文昌采集的一株野生杂色曲霉接种到质量分数分别为0.9%和3.5%的NaCl溶液中制成孢子悬浮液,将孢子悬浮液均匀喷洒到铜试样表面后进行恒温恒湿试验,试验不同周期后采用体视学显微镜、扫描电子显微镜观察铜试样的腐蚀形貌,采用X射线光电子能谱仪分析试验14 d的试样表面和氩离子刻蚀15 s后的成分。结果 纯铜在NaCl薄液膜下的腐蚀产物具有明显的双层结构,内层靠近基体的为致密的Cu2O钝化层,外层为疏松的Cu2(OH)2CO3和Cu2(OH)3Cl组成的Cu(II)碱式盐;无菌时,铜表面出现大量蓝绿色的Cu(II)碱式盐,杂色曲霉存在时,铜表面腐蚀产物主要为红棕色的Cu2O钝化膜,仅有少量Cu(II)碱式盐零星分布在Cu2O膜外层;0.9% NaCl薄液膜与霉菌共同作用时,试样表面腐蚀产物主要为Cu2O,当薄液膜中盐的质量分数升高到3.5%时,霉菌数量减少,Cu(II)碱式盐较0.9% NaCl薄液膜组增多。结论 纯铜的腐蚀产物由内层的Cu2O钝化层、外层的Cu2(OH)2CO3和Cu2(OH)3Cl组成双层结构。杂色曲霉通过呼吸作用影响液膜中的O2浓度进而影响铜的腐蚀产物组成,霉菌存在时腐蚀产物中Cu(II)碱式盐显著减少。含氯液膜与霉菌共同作用时,液膜中的NaCl浓度通过影响杂色曲霉的生长活性而影响腐蚀产物组成。     

Zn-Cu-Al层状水滑石基复合氧化物的合成及光催化性能

采用球磨-水热法合成不同投料摩尔比的Zn-Cu-Al层状水滑石(LDHs),LDHs前驱体经焙烧后转变为Zn-Cu-Al复合金属氧化物。用XRD、SEM、TG、DTA和BET等方法对样品前驱体及焙烧产物进行表征。在模拟太阳光照下,以甲基橙(MO)溶液为目标降解物,研究金属离子摩尔比、焙烧温度等对样品的结构、组成形貌及光催化活性的影响。结果表明:当n(Zn):n(Cu):n(Al)投料比为1:2:1时,获得的前驱体具有典型的水滑石片层状结构。最佳前驱体经500℃焙烧后样品中出现Zn O、Cu O和Zn Al2O4 3种氧化物的特征衍射峰,具有较好的结晶度,其比表面积为70.1 m2/g,孔体积为0.26 cm3/g。在模拟太阳光照射下60 min后,0.5 g/L催化剂对25 mg/L甲基橙溶液的脱色率达93.1%。     

气体介质对常压等离子体还原氧化铜的影响

目的研究不同等离子体还原介质和还原时间对氧化铜还原的影响。方法采用等离子焰流扫描试样,应用扫描电镜观察还原后试样的表面微观形貌,通过X射线衍射仪分析试样处理前后表面相成分的变化。结果采用N2+热氨为气体介质,其还原产物为Cu4O3和Cu3O,相对于其他气体介质得到的还原产物Cu2O,能将Cu2+还原至更低的价态。还原时间为40 s时,主要还原产物为Cu3O,其氧含量低于Cu O,随着时间延长,亚稳相Cu3O逐渐转变成较稳定的Cu2O;当还原时间为100 s时,析出Cu单质。结论 N2+热氨是还原性较强的气体介质。氧化铜中铜离子价态随还原时间增加而降低,同时伴随亚稳定相Cu3O向Cu2O转变现象。还原过程中高能电子对Cu O颗粒有加热熔融作用,激发态的活性粒子发挥主要的还原作用。     

通过水溶液还原法用抗坏血酸制备纳米铜颗粒(英文)

通过水溶液还原法用抗坏血酸还原Cu2+制备纳米铜颗粒,并研究溶液pH和Cu2O平均粒径对纳米铜颗粒制备的影响。在溶液pH值为3、5和7时,可制得铜颗粒,并且在pH=7时制得的铜颗粒粒径最小。在溶液pH为9和11时无法制得铜颗粒。Cu2O的平均粒径能影响铜粉的粒径。Cu2O的平均粒径越大,得到的铜颗粒越大。通过对反应过程中不同时间点收集的样品进行XRD分析,可探索出反应的进程。在反应过程中,Cu(OH)2首先作为前驱体出现,然后被还原为Cu2O,最后被还原为铜颗粒。     

Cu/Q235A异质钎焊接头的性能及耐腐蚀性

使用BAg30T药芯钎料对Cu/Q235A异种金属进行感应钎焊试验,研究了Cu/Q235A异种金属钎焊接头的力学性能和耐腐蚀性能.结果 表明:Cu/Q235A钎焊接头的抗拉强度为214 MPa,与铜的抗拉强度接近,接头性能良好.在Cu/Q235A钎焊接头中,耐腐蚀性能从高至低依次为Cu＞BAg30T钎缝＞Q235A;钎焊接头经盐雾腐蚀96 h后抗拉强度下降了33％,腐蚀480 h后抗拉强度下降了74％,钎焊接头抗拉强度受盐雾腐蚀影响较大;腐蚀产物主要存在钢侧和钎缝处,未被腐蚀产物覆盖的表面存在点蚀,且随着腐蚀时间的增加腐蚀坑密度和尺寸变大,微观观察表明腐蚀产物呈现棉球状和絮状,腐蚀产物主要为Fe2O3和Fe3O4,且O2与C1-参与腐蚀反应.     

双氧水改性二氧化钛的光催化性能研究

研究了用微乳法制备纳米二氧化钛粉末的工艺，以及在紫外光照射下，TiO2和H2O2分别以及两者结合对于甲基橙溶液的降解作用。结果表明用微乳法可以制备粒度为23．2nm的纳米TiO2粉末；在紫外光照射下，H2O2可以有效地降解甲基橙溶液；当H2O2浓度从1mmol／L增加到10mmol／L，甲基橙的吸光度直线下降；当H2O2浓度达到10mmol／L时，降解率可以达到99％；TiO2也可以有效地降解甲崔橙溶液，当TiO2的浓度为0．50～0．75g／L时，降解率最大；用H2O2对TiO2进行改性后，可以有效地降解甲基橙溶液，固定TiO2的量为0．5g／L时，当H202浓度为4mmol／L时，甲基橙溶液的吸光度达到最低；当H2O2浓度处于10mmol／L以上时，甲基橙溶液的吸光度却出现无规则的变化。     

光催化二氧化钛溶胶的制备

以TiOSO4为原料、氨水为沉淀剂、H2O2为络合剂合成出含有针状锐钛矿晶粒的TiO2溶胶,该溶胶具有光催化活性.用XRD、TEM等对产物结构和形貌进行了表征.结果表明钛酸沉淀pH值、H2O2的加入量、回流时间对二氧化钛溶胶光催化效果有影响.当PTA回流4.75 h所得的RS-4.75的光催化效果最好,在可见光下对甲基橙降解率为52.8%.在PTA溶胶回流过程中增加冷却过程,相对于无冷却过程,材料的光催化性能得到了提高.PTA先回流3 h,溶胶冷却至室温,再回流1 h的溶胶的甲基橙降解率为48%,高于RS-4溶胶的光催化性能.     

Fabrication of Dy2Ti2O7 nanocrystalline at 700 °C and its photocatalytic activity

Dy₂Ti₂O₇ nanocrystalline was fabricated by a soft-chemistry route named as citric acid sol–gel method (CAM). The fabricating process was monitored by XRD, FT-IR and TG-DTA methods. It was found that compared with traditional solid state reaction (SSR), Dy₂Ti₂O₇ was synthesized at a relatively low temperature (700 °C) and with shortened reaction time (2 h). The morphology and surface composition of obtained products were determined by TEM and SEM-EDX experiments. Results showed that the obtained Dy₂Ti₂O₇ with good dispersibility were all square-like; the average size was about 50 nm and there was ample oxygen-deficient (40%) on the product interfaces. Also, the obtained products had higher BET surface area (25.10 m²/g). These properties are very helpful for a catalyst to achieve excellent photocatalytic activity. Photodecomposition of methyl orange was used as the model system to evaluate its photocatalytic property. It was found that Dy₂Ti₂O₇ showed good photocatalytic activity and the decomposition rate of methyl orange was about 99% within 60 min.     

Ag-TiO2复合纳米颗粒的自组装法制备及其光催化性

采用空气-水界面自组装法制备TiO2纳米粒子,将其放入AgNO3溶液中浸泡,后在较低温度下进行热处理(400℃),获得Ag-TiO2复合纳米颗粒.利用X射线衍射(XRD)仪、扫描电镜(SEM)、透射电镜(TEM)、紫外可见光谱(UV-vis)等分析测试手段进行表征.结果表明:复合粒子可以显著提高TiO2颗粒光催化活性.以甲基橙为模拟污染物,经过光催化试验,证实复合纳米粒子具有较好的光催化活性,降解率达到96.25％.     

掺Ag量对绢云母负载纳米二氧化钛性能的影响

以绢云母为载体,采用水解-沉淀法制备出了绢云母负载纳米TiO2粉体（TiO2/M）,在粉体表面沉积不同量的Ag2CO3,经400℃焙烧,制得不同掺Ag量的绢云母负载TiO2光催化剂,采用TG、XRD、SEM、EDS、UV等手段对样品进行了性能表征;并以日光色镝灯为光源,甲基橙为模拟污染物检测其光催化活性,研究了Ag的掺杂量对粉体中TiO2晶相结构、粒度和光催化性能的影响。结果表明：纳米TiO2均匀负载在绢云母上形成包覆层,Ag的掺杂抑制了TiO2晶粒的长大,减缓锐钛矿向金红石相的转变,同时Ag的掺杂形成新的能级结构,随Ag＋/Ti4＋摩尔比的增加,样品对光的吸收边逐渐红移至440～520 nm,具有明显的可见光响应,当Ag＋/Ti4＋=0.05时,制得样品对甲基橙的光催化降解率是没有掺Ag的样品的1.5倍,相同条件下重复利用4次,该样品60 min对甲基橙的降解率仍然可达34%。     

CdS修饰TiO2纳米管阵列的制备及光催化性能研究

首先通过恒压阳极氧化法在纯钛箔表面制备TiO2纳米管阵列,其次运用电化学沉积法在TiO2纳米管阵列表面修饰CdS颗粒,最后表征其对甲基橙的光催化降解性能.研究表明,通过电化学沉积可以在管阵列表面获得均匀分布的CdS纳米颗粒.TiO2纳米管阵列在经过CdS修饰后,对可见光的吸收范围明显增大;光照2 h后,对甲基橙的降解效率由修饰前的57.1%提高到修饰后的76.4%,COD的去除率也从49%提高到70.6%.     

Synthesis of Bi2S3 microsphere and its efficient photocatalytic activity under visible-light irradiation

A novel Bi₂S₃ microsphere was fabricated through one-pot urea-assisted solvothermal method. The synthesized Bi₂S₃ microsphere was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FT-IR) and thermal gravimetric analysis and differential thermal analysis (DTA-TG). Subsequently, the photocatalytic performances of Bi₂S₃ microsphere were evaluated by photocatalytic degradation of methyl orange (MO) simulation solution under visible-light irradiation. The results show that, Bi₂S₃ microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions, whose degradation rate could reach 91.07% within 180 min. Besides, a tentative photocatalytic reaction mechanism was discussed according to the energy band position. Therefore, this work indicated a simplistic approach for the fabrication of visible-light responsive Bi₂S₃ microsphere photocatalyst, which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.     

Enhanced photocatalytic properties of ultra-long nanofiber synthesized from pure titanium powders

Using Ti powder as reagent,ultra-long TiO2 nanofibers were prepared via hydrothermal method in NaOH solution.The samples were char-acterized respectively by means of field emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM) with selected area electron diffraction (SAED),and X-ray diffraction (XRD).The diameter and the length of the ultra-long TiO2 nanofiber were ～100 nm and >200μm,respectively.The ultra-long TiO2 nanofibers were anatase after heat treatment at 450 ?C for 1 h.Moreover,the optical properties of the products were investigated by UV-visible light absorption spectrum.Furthermore,methyl orange was used as a target molecule to estimate the photocatalytic activity of the specimens.Under the same testing conditions,the photocatalytic activity of the ultra-long TiO2 nanofibers was higher than that of P25.Direct electrical pathway and improved light-harvesting efficiency were crucial for the superior photocatalytic activity of the ultra-long TiO2 nanofibers.     

Dual-Mode Nanoporous Copper by Dealloying Al-Cu-Nacl Bulk Alloys and Its High Degradation Efficiency Toward Methyl Orange

In this work, a facile synthesis route was applied to fabricate nanoporous copper (NPC). As-sintered AlCu bulk alloys with (or without) NaCl that were fabricated by powder metallurgy were taken as precursors during the preparation of NPC via chemical dealloying. The effects of NaCl in the alloys on precursors and products were investigated. Scanning electron microscope (SEM) examinations showed that the addition of NaCl is really beneficial to the formation of a dual-mode pore structure. The x-ray diffraction (XRD) revealed that the AlCu phase formed at the powder metallurgy stage could be completely corroded in HCl solution in the as-dealloyed products, whereas it remains unchanged in the NaOH condition. SEM images showed that NPC was characterized by a three-dimensional, bicontinuous, uniform, or dual-mode ligament-channel structure with nanoscale length. There were no obvious AlCu blocks or other bulks in the NPC sample fabricated from Al67Cu33 alloys with NaCl. In addition, it exhibited hierarchical structures with two distinctive pore sizes, which results in the best photocatalytic properties of NPC. Moreover, the photocatalytic properties of NPC for methyl orange (MO) degradation in water solution were evaluated, and it miraculously showed enhanced photocatalytic performance of exceeding 99% at even a brief time.     

碳量子点及其功能化与银复合的催化性能研究

采用水热反应釜法制备碳量子点以及氯化亚砜功能化碳量子点,然后分别与用乙二醇还原的银纳米粒子进行复合,利用FTIR、TEM对样品进行表征,利用荧光分光光度计测试荧光谱,紫外-可见分光光度计测试吸收谱和甲基橙浓度。结果表明：碳量子点的平均粒径约3.5nm,类球形银纳米粒子的平均粒径约18nm。银纳米粒子和碳量子点复合催化剂能够使荧光猝灭,使可见光区的吸收增强。复合催化剂比单独的银纳米粒子和碳量子点的催化能力更好。银纳米粒子和碳量子点以1：2的比例复合时催化效率最高。氯化亚砜功能化的碳量子点与银纳米粒子复合能提高降解甲基橙的浓度和降解速率,12分钟内降解完50mL,50mg/L的甲基橙。     

Low-temperature synthesis of N-TiO2 sol and characterization of N-TiO2 coating on cotton fabrics

To extend the application of N-TiO₂ to substrates with low thermal resistance, N-TiO₂ sol has been successfully synthesized at low temperature by reflux method and N-TiO₂ coating on cotton fabrics has been successfully prepared in a dip-coating process. Several characterization tools, such as X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV–vis diffuse reflectance spectroscopy, were employed to study the phase structures, morphologies, the chemical states and optical properties of the samples. The photocatalytic properties of the prepared products were measured with the degradation of methyl orange at room temperature under visible light irradiation. In comparison with TiO₂-cotton, the remarkable enhancement in the visible light photocatalytic performance of the N-TiO₂-cotton could be attributed to the existence of N-TiO₂ with narrow band gap. The photocatalytic performances of the N-TiO₂-cotton were maintained for the cycling experiments, indicating that N-TiO₂-cotton could be used as stable and efficient visible-light-induced self-cleaning materials.     

Polyacrylamide gel synthesis and photocatalytic performance of Bi2Fe4O9 nanoparticles

In this report, a polyacrylamide gel route is introduced to synthesize Bi₂Fe₄O₉ nanoparticles. It is demonstrated that high-phase-purity Bi₂Fe₄O₉ nanoparticles can be prepared using different chelating agents. Interestingly, however, the particle size of the products is found to be dependent on the choice of chelating agent. The use of EDTA as the chelating agent allows the production of Bi₂Fe₄O₉ nanopowder with a relatively smaller particle size. The photocatalytic experiments reveal that the as-prepared Bi₂Fe₄O₉ nanoparticles possess excellent photocatalytic activity for oxidative decomposition of methyl red under ultraviolet and visible light irradiation. Magnetic hysteresis loop measurement shows that the Bi₂Fe₄O₉ nanoparticles exhibit a weak ferromagnetic behavior at room temperature.