磁性氧化石墨烯/TiO_2复合材料的制备及光催化降解染料废水的研究

为了提高TiO2的光催化性能,采用Hummers法自制氧化石墨、纳米TiO2、FeCl3等为原料制备了磁性氧化石墨烯/TiO2(磁性GO/TiO2)复合光催化材料。以活性艳红X-3B为模拟废水,对该催化剂在紫外光下的催化活性进行了评价。结果表明,TiO2/GO材料中GO含量为3%时光催化活性最好,磁性GO/TiO2复合材料GO含量为8%时在1.4 h时可以达到93%的降解率。     

磁性氧化石墨烯/TiO_2复合材料的制备及光催化性能的研究

利用水热法以氧化石墨烯为载体制备磁性氧化石墨烯/TiO2光催化复合材料,对不同Fe3O4掺杂比例的复合光催化剂采用SEM、XRD、UV-Vis等测试方法对其进行表征,并在紫外灯照射下研究了对活性艳红溶液光催化性能。结果显示,Fe3O4及氧化石墨烯的引入会提高TiO2的光催化性,这主要是因为提高了TiO2的导电性和吸附性。由此可见Fe3O4、氧化石墨烯与TiO2复合,能够有效提高TiO2的催化性能。     

磁性氧化石墨烯/TiO_2复合材料的制备及光催化性能的研究

利用水热法以氧化石墨烯为载体制备磁性氧化石墨烯/TiO2光催化复合材料,对不同Fe3O4掺杂比例的复合光催化剂采用SEM、XRD、UV-Vis等测试方法对其进行表征,并在紫外灯照射下研究了对活性艳红溶液光催化性能。结果显示,Fe3O4及氧化石墨烯的引入会提高TiO2的光催化性,这主要是因为提高了TiO2的导电性和吸附性。由此可见Fe3O4、氧化石墨烯与TiO2复合,能够有效提高TiO2的催化性能。     

二氧化钛/氧化石墨烯复合光催化剂的合成

采用水热法,以钛酸四正丁酯及氧化石墨烯（GO）为原料,在水性体系中合成了一系列具有不同GO质量分数的TiO2/GO复合光催化剂。FE-SEM分析结果表明,分散的钛酸四正丁酯以多分子层的形式吸附到氧化石墨烯的表面,最后在水热过程中转化为锐钛型TiO2粒子。当氧化石墨烯的质量分数低于3%时,产物中含有纯TiO2微球及TiO2/GO复合物;当氧化石墨烯质量分数大于5%时,产物为单纯的TiO2/GO复合物。电化学性能测试结果表明,GO复合后,TiO2电极中载流子的传输效率提高。氧化石墨烯复合量为10%时,复合光催化剂显示了对亚甲基蓝最佳的光催化活性。当复合氧化石墨烯转化为石墨烯后,其光催化活性可得到进一步大幅度的提高。     

钐掺杂TiO2纳米管阵列的光催化性能研究

以工业级纯钛箔为模板,硝酸钐为钐物种掺杂给体,采用阳极氧化法制备钐掺杂的TiO2光催化剂,用SEM、XRD对制备的样品进行表征,以甲基橙为模拟污染物,考察了钐掺杂的TiO2光催化剂的光催化活性。结果表明:制备的光催化剂为锐钛矿相和少量金红石相的混晶;硝酸钐掺杂浓度为0.001 mol/L,其光催化性能最好,且光催化重复使用性能良好。     

光催化剂膜的制备及活性评价

采用溶胶-凝胶法在玻璃纤维布上成功制备了锐钛矿型TiO2薄膜。并以腐殖酸为处理对象,对TiO2膜的光催化氧化活性进行评价。结果表明,该固定TiO2膜光催化体系对降解腐殖酸有良好的效果,反应3 h,腐殖酸的降解率达52.9%。显示了光催化氧化法在水处理中的良好应用前景。     

可见光响应Pt掺杂纳米TiO2的光催化氧化NOx性能

采用溶胶-凝胶法制备不同Pt掺杂比例的Pt-TiO2光催化剂。通过XRD、XPS、UV-vis表征光催化剂结构,在紫外光及可见光下考察其对NOx的光催化氧化活性。结果表明,所制备的Pt-TiO2均为锐钛矿相,对NOx有明显的可见光降解效果,并且以Pt/Ti比为0.4%时,其光催化活性最高。与P25及TiO2相比,Pt-TiO2在紫外光及可见光下的光催化活性均有较大提高,其NO转化率明显提高,NO2选择性生成率明显降低,归因于Pt的掺杂引入了杂质能级并促进了催化剂的光生电子-空穴对的分离。     

TiO_2/AC复合光催化剂的研究进展

TiO2是绿色水处理技术——光催化氧化法常用的催化剂,近年来,为解决TiO2催化活性低、难以回收再利用等问题,将其负载到活性炭上得到的TiO2/AC复合光催化剂已成为光催化领域研究的热点。目前,国内外研究者对TiO2/AC的光催化机理、TiO2与AC的协同作用机理、TiO2/AC的制备方法以及TiO2的晶型与负载量、外加试剂及废水pH值等因素对TiO2/AC光催化活性的影响进行了较为深入的研究。今后的研究趋势是:一方面在制备方面加强TiO2与AC结合的牢固性以提高其使用效率,另一方面开发在自然光源下可以产生良好催化活性的复合光催化剂。     

微乳液法制备纳米SiO2/TiO2及其光催化性能

以无机物聚合硅酸为硅源、硫酸钛为钛源,采用微乳液法制备了SiO2/TiO2复合光催化剂,考察了制备条件对SiO2/TiO2光催化活性的影响,并利用SEM、FTIR、XRD和BET等技术手段对光催化剂进行了表征。结果证明,SiO2和TiO2颗粒之间存在着强的相互作用,形成了Ti-O-Si键,从而抑制了TiO2粒径的增大,延缓了TiO2由锐钛矿相向金红石相的转变。对甲基橙等染料的光催化降解实验结果表明,SiO2/TiO2的光催化活性并非随着TiO2的含量增加而提高,当硅与钛物质的量比为1∶1并在160℃的温度下水热合成2.5 h时,SiO2/TiO2光催化剂在紫外光照15 min后对甲基橙的脱色率为85.5%,与同等条件下制备的TiO2相比具有更好的光催化活性和更大的比表面积。     

TiO2光催化剂的离子交换法制备及性能研究

采用离子交换法制备了TiO2光催化材料。通过考察离子交换树脂用量、反应温度、反应时间等因素对所得光催化剂用于紫外光照射下降解亚甲基蓝的性能的影响,得出离子交换树脂用量为500g、反应时间为5h、反应温度为54℃所制得的纯TiO2的光催化性能最佳,经紫外光照射120min后,溶液的脱色效率最高为98．38％。XRD结果表明,所得产品为纳米级锐钛矿型TiO2和金红石型TiO2的混合物粒子,其中锐钛矿型TiO2质量分数为80．8％。     

Graphene、CNTs协同TiO2/ACF光催化净化甲醛研究

采用浸渍和喷涂法制备了TiO2/ACF、CNTs/TiO2/ACF和Graphene/TiO2/ACF光催化复合材料。以甲醛为目标化合物在光催化反应器中,254nm紫外灯作光源,光强20W,甲醛初始浓度2.41mg.L-1条件下,研究了甲醛在TiO2/ACF、CNTs/TiO2/ACF和Graphene/TiO2/ACF光催化复合材料上的吸附-光催化净化行为。初步结果表明复合光催化剂活性高低顺序为:Graphene/TiO2/ACF>CNTs/TiO2/ACF>TiO2/ACF。     

Graphene‐based composite with microwave absorption property prepared by in situ reduction

Binary composite of graphene/poly(ethylene oxide) (PEO) with microwave absorption property is prepared by in situ reduction process. Graphite oxide (GO) is prepared from flake graphite by modified Hummers' method and further dispersed in distilled water to get GO solution. Then, PEO powder is slowly added into GO solution to get GO/PEO solution, and graphene/PEO composites is prepared via a facile and quick reduction process in GO/PEO solution. PEO and graphene/PEO composites are characterized by scanning electron microscopy, atomic force microscopy, thermo gravimetric analysis, and vector network analyzer. The results show that graphene is uniformly dispersed in PEO matrix because GO and PEO can be uniformly dispersed at molecular level due to their water‐solubility and the agglomeration of graphene can be prevented by PEO macromolecular chains during in situ reduction process. Graphene/PEO composite has better thermal stability than PEO, which can be explained by the graphene restoration of sp² bonded carbon structure. Meanwhile, graphene/PEO composite shows excellent microwave absorption property at low grapheme content. The minimum reflection loss of graphene/PEO composite is up to −20.0 dB when the content of graphene is only 1 wt%. POLYM. COMPOS., 35:461–467, 2014. © 2013 Society of Plastics Engineers     

氧化石墨烯改性环氧树脂涂料的制备及防腐性能

环氧树脂在溶剂蒸发过程中容易产生微孔,影响其防腐蚀性能。为了提高其对腐蚀介质的阻碍能力,本文采用密闭氧化法制备氧化石墨烯,再利用湿式转移法将氧化石墨烯水溶液分散在环氧树脂中,制备氧化石墨烯/环氧树脂防腐涂料。通过红外光谱（FTIR）、X射线衍射（XRD）和拉曼光谱（Raman）分析氧化石墨烯的结构变化,利用开路电位测试（OCP）、水接触角、腐蚀形貌和气体透过率分析氧化石墨烯/环氧树脂涂料的防腐性能。结果表明,氧化石墨烯/环氧树脂（GO/EP）涂料的开路电位和水接触角分别为0.181V和86.12°,与纯环氧树脂涂料相比,分别提高了0.066V和10.5°;当GO/EP浸泡在3.5%NaCl溶液中腐蚀20天后,表面仅产生了粗糙化,涂层稳定性好,屏障性能强;与EP涂层相比,GO/EP涂层的O₂和H₂O渗透率分别降低了51.2%和65.5%。     

微波法制多孔石墨烯及对亚甲基蓝的吸附性能

以改进的Hummers法合成的氧化石墨烯为自组装原料,通过微波加热的方式制备三维多孔石墨烯材料.并采用场发射扫描电子显微镜、傅立叶红外光谱仪、X射线衍射仪对石墨、氧化石墨烯、三维多孔石墨的微观形貌和内部结构进行表征分析.以亚甲基蓝为吸附质、三维多孔石墨烯为吸附剂,研究其吸附性能.结果表明,三维多孔石墨烯材料的最大吸附量...     

A facile one-step solvothermal synthesis of graphene/rod-shaped TiO₂ nanocomposite and its improved photocatalytic activity

Graphene sheets were obtained through solvothermal reduction of colloidal dispersion of graphene oxide in benzyl alcohol. The graphene/rod-shaped TiO(2) nanocomposite was synthesized by this novel and facile solvothermal method. During the solvothermal reaction, both the reduction of graphene oxide and the growth of rod-shaped TiO(2) nanocrystals as well as its deposition on graphene occur simultaneously. The photocatalytic activity of graphene/rod-shaped TiO(2) and graphene/spherical TiO(2) nanocomposites was compared. In the photocatalytic degradation of methyl orange (MO), the graphene/rod-shaped TiO(2) nanocomposite with the optimized graphene content of 0.48 wt% shows good stability and exhibits a significant enhancement of photocatalytic activity compared to the bare commercial TiO(2) (P25) and graphene/spherical TiO(2) nanocomposite with the same graphene content. Photocurrent experiments were performed, which demonstrate that the photocurrent of the graphene/rod-shaped TiO(2) nanocomposite electrode is about 1.2 times as high as that of the graphene/spherical TiO(2) nanocomposite electrode. The photocatalytic mechanism of graphene/rod-shaped TiO(2) nanocomposite was also discussed on the basis of the experimental results. This work is anticipated to open a possibility in the integration of graphene and TiO(2) with various morphologies for obtaining high-performance photocatalysts in addressing environmental protection issues.     

镍负载二氧化钛/PEI/石墨烯纳米复合催化剂的制备与研究

首先采用改进的Hummers法制备了氧化石墨烯(GO),再以聚乙烯亚胺(PEI)修饰的氧化石墨烯为载体,并以硫酸钛和氯化镍为前驱体,利用水热法在180 ℃下以PEI为交联剂制得镍负载的TiO2/PEI/石墨烯纳米复合催化剂。通过紫外可见分光光度计(UV-vis)、傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)等测试手段对催化剂进行了表征。结果表明,Ni-TiO2/PEI/RGO纳米复合催化剂中镍负载TiO2纳米粒子与石墨烯能够均匀复合,并具有较小的晶粒尺寸。以对硝基苯酚(4-NP)为降解目标物,考察了该催化剂在NaBH4存在下还原4-NP的催化活性。结果表明,镍负载的TiO2/PEI/石墨烯纳米复合催化剂具有良好的重复催化活性,其降解率为98%,催化剂重复使用10次后,降解率仍能保持90%以上。     

Synthesis of reduced graphene oxide-anatase TiO2 nanocomposite and its improved photo-induced charge transfer properties

The construction of reduced graphene oxide or graphene oxide with semiconductor has gained more and more attention due to its unexpected optoelectronic and electronic properties. The synthesis of reduced graphene oxide (RGO) or graphene oxide-semiconductor nanocomposite with well-dispersed decorated particles is still a challenge now. Herein, we demonstrate a facile method for the synthesis of graphene oxide-amorphous TiO(2) and reduced graphene oxide-anatase TiO(2) nanocomposites with well-dispersed particles. The as-synthesized samples were characterized by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis absorption spectroscopy, Fourier transform infrared spectrometry, and thermogravimetric analysis. The photovoltaic properties of RGO-anatase TiO(2) were also compared with that of similar sized anatase TiO(2) by transient photovoltage technique, and it was interesting to find that the combination of reduced graphene oxide with anatase TiO(2) will significantly increase the photovoltaic response and retard the recombination of electron-hole pairs in the excited anatase TiO(2).     

Co负载TiO2/氧化石墨烯纳米复合材料的水热法合成及光催化性能

首先采用改进的Hummers法制得氧化石墨烯(GO)，再利用氧化石墨烯为基体，硫酸钛和氯化钴为前驱体，并通过修饰石墨烯的聚乙烯亚胺(PEI)为交联剂，采用一步水热法成功合成了三维柱状自组装的钴负载TiO2/氧化石墨烯纳米复合材料(Co@/TiO2/PEI/RGO)。通过紫外-可见吸收光谱法、X射线衍射、透射电子显微镜和X射线光电子能谱对复合材料的结构和光电性能进行了表征。在紫外和可见光照条件下，研究了复合材料的光催化降解亚甲基蓝(MB)的性能。结果表明钴负载TiO2/RGO纳米复合材料具有较高的光催化活性，在60min内降解率为99%，可循环至少10次。     

石墨烯负载二氧化钛复合材料及光催化降解甲基橙

以天然鳞片石墨为原料,用改进的Hummers法氧化制备氧化石墨烯,然后用葡萄糖还原制得石墨稀,再用溶胶一凝胶法复合制备了TiO2／2;墨烯的复合材料。用FI-IR、Raman、AFM、SEMvR）3LTGA对石墨烯和TiO2／2;墨烯复合材料进行了表征,并在紫外光照射条件下对比石墨烯、TiO2、TiO：／2;墨烯复合材料对甲基橙的降解效果。结果表明,在紫外光照射下,TiO2的负载率为35％时,TiO2／2;墨烯复合材料光催化降解甲基橙的催化效率明显大于单纯TiO2及石墨烯,光催化4小时后,脱色率达到85％。TiO2／2;墨烯复合材料不失为一种有潜力的光催化降解染料废水催化材料。