以多孔陶粒为载体的纳米Ag/N-TiO_2光催化膜的制备与表征

以多孔陶粒为载体,采用改进的溶胶-凝胶工艺成功地制备了具有可见光催化活性的纳米Ag/N-TiO2膜.研究了Ag,N或Ag/N的掺杂对TiO2的晶相结构、粒度、成分和光催化活性的影响.采用X射线衍射、紫外-可见分光光谱分析、X射线能谱仪和扫描电子显微镜进行了表征.以含油的废水和新鲜球菌为污染物模型估算其光催化活性和抗菌杀菌性.结果表明:银和氮的复合掺杂对纳米TiO2膜的光催化活性显著改善.负载Ag/N-TiO2膜的多孔陶粒对水中的油和细菌的降解速率是纯TiO2陶粒的3倍多.这种陶粒可用于油水处理和养鱼池的抗菌杀菌及过滤处理.     

不同氮源制备的N-TiO2及其光催化活性比较

分别以乙二胺、三乙胺和尿素为氮源,采用溶胶-凝胶法成功制备不同氮掺杂的TiO2光催化剂,通过X射线衍射(XRD)、扫描电镜(SEM)、激光粒度仪、紫外-可见漫反射(UV-Vis DRS)对样品进行表征,以亚甲基蓝为目标降解物,在紫外与可见光下分别比较不同氮源掺杂对光催化剂活性的影响,实验表明,在紫外光照下,以尿素为氮源制备的N-TiO2具有较高的催化活性,反应2h,降解率可达96.2％;而在可见光下,以三乙胺为氮源制备的N-TiO2具有较高的催化活性,反应6h,降解率可达92.5％;光催化降解亚甲基蓝的过程近似符合拟一级反应动力学;以三乙胺为氮源制备的TiO2光催化剂在重复使用4次后仍保持较高的催化活性.     

掺N纳米ZnO的制备及光催化活性

采用溶胶-凝胶法合成纳米ZnO,用碳酸铵溶液浸渍的方法对其进行N掺杂。利用X射线衍射仪,透射电子显微镜,X射线能谱仪,Fourier红外光谱仪,X射线光电子能谱仪,紫外-可见光谱仪对产物结构进行了表征,通过可见光催化降解甲基橙对N-ZnO的光催化活性进行了考察。结果表明:合成的ZnO颗粒大小在20～30 nm,N的掺杂没有改变ZnO的晶型,N在ZnO晶格中形成N—Zn—O键;N掺杂拓宽了ZnO的可见光吸收范围。N-ZnO作为光催化剂在可见光作用下能有效降解甲基橙,表现出较高的可见光催化活性。当(NH4)2CO3和ZnO的摩尔比为0.20时,N-ZnO的光催化性能最好。     

WO_3/N-TiO_2异质节可见光催化降解亚甲基蓝

以尿素为氮源,采用溶胶凝胶法制备N掺杂TiO_2,然后与钨酸铵混合研磨,通过高温焙烧的方法原位制备WO_3复合N掺杂TiO_2的异质节光催化材料。分别采用X射线衍射(XRD)、紫外-可见分光光度计(UV-Vis)对样品进行分析,考察样品的光吸收阈值变化。以亚甲基蓝为降解底物,考察了样品的可见光催化处理染料废水效果,结果表明,原位制备的WO_3和N掺杂TiO_2异质节光催化材料对亚甲基蓝表现出良好的可见光催化活性。     

掺N负载型宽禁带TiO_2光催化材料的制备

实验以CO(NH2)2(尿素)为氮源,活性炭为载体,采用溶胶-凝胶法制备了TiO2、N-TiO2(TN)、TiO2负载型TiO2粉体(T/AC)和N掺杂活性炭负载型TiO2粉体。通过XRD、SEM、OM等测试方法进行分析,并通过甲基橙的分解实验检测粉体光催化效果。结果表明,N可能以填隙或替代方式掺杂到TiO2,TiO2中氮的引入能将TiO2光催化响应波长红移至可见光,掺杂负载后的样品的催化活性强于TN系列和T/AC系列。     

Synthesis and Photocatalytic Activity of N-doped ZnO

采用溶胶–凝胶法合成纳米 ZnO，用碳酸铵溶液浸渍的方法对其进行 N 掺杂。利用 X 射线衍射仪，透射电子显微镜，X 射线能谱仪，Fourier红外光谱仪，X 射线光电子能谱仪，紫外–可见光谱仪对产物结构进行了表征，通过可见光催化降解甲基橙对 N-ZnO 的光催化活性进行了考察。结果表明：合成的 ZnO 颗粒大小在 20～30 nm，N 的掺杂没有改变 ZnO 的晶型，N 在 ZnO 晶格中形成 N—Zn—O 键；N 掺杂拓宽了 ZnO 的可见光吸收范围。N-ZnO 作为光催化剂在可见光作用下能有效降解甲基橙，表现出较高的可见光催化活性。当（NH4）2CO3和 ZnO 的摩尔比为 0.20 时，N-ZnO 的光催化性能最好。     

多种光源下氮掺杂TiO_2光催化降解染料废水的研究

以尿素为氮源,采用溶胶-凝胶法制备了氮掺杂纳米TiO2粉末,以甲基橙溶液为模拟染料废水,分别在可见光、模拟太阳光和紫外光条件下,研究了氮掺杂纳米TiO2光催化降解染料废水的性能。结果表明:氮掺杂可以提高TiO2的可见光催化活性;氮含量和煅烧温度对氮掺杂TiO2光催化活性影响较大,n(N)∶n(Ti)为10%且经500℃煅烧的氮掺杂TiO2在可见光和模拟太阳光下均具有最佳的光催化活性;然而在紫外光下,氮掺杂TiO2的光催化活性低于未掺杂的TiO2样品。     

负载金的掺氮二氧化钛的制备及其可见光催化性能

以纳米管钛酸为前驱体,采用水热法先制备得到新型N掺杂二氧化钛,然后用沉积沉淀法在N掺杂二氧化钛表面负载微量贵金属Au,制备得到负载Au的掺N二氧化钛.利用TEM、XRD、XPS、ESR和DRS等手段研究了样品的形貌、晶体结构、元素化学态和光谱吸收性质.样品光催化活性通过可见光催化降解丙烯进行评价,结果表明,样品N-TiO2和Au/N-TiO2具有明显的可见光(λ≥420 nm)催化活性.ESR结果表明,掺氮过程中生成的束缚单电子的氧空位是样品具有可见光响应的原因.     

不同钛源掺碳二氧化钛可见光催化活性的研究

为拓展二氧化钛对可见光的响应,采用溶胶-凝胶法、水解法制备了碳掺杂二氧化钛粉末。用X射线衍射、比表面分析和紫外-可见光漫反射吸收光谱等方法对制备的样品进行了表征,对可见光照射下的光催化活性进行了测试,并考察了煅烧温度对光催化活性的影响。结果表明：碳掺杂致使二氧化钛在可见光区的光吸收增强,在降解甲基橙的实验中表现出良好的可见光催化活性;随煅烧温度的增加,晶粒增大,可见光催化活性减弱。     

氮掺杂制备锐钛矿型纳米TiO2及降解甲基橙的研究

采用溶胶凝胶法制备了氮掺杂TiO2光催化剂。考察了氮的掺杂量、热处理温度对TiO2光催化能力的影响。用XRD、 SEM和紫外-可见光分度计对样品的晶型、形貌和光催化性能进行表征。结果表明氮的掺杂有助于改善TiO2的光催化性能,在灯光照射下5％N-TiO2煅烧温度为450℃时表现出较高的光催化活性和降解甲基橙溶液的能力,在80 min内降解甲基橙溶液达到了98％。     

One-step hydrothermal synthesis of N-doped TiO2/C nanocomposites with high visible light photocatalytic activity

N-doped TiO(2) nanoparticles modified with carbon (denoted N-TiO(2)/C) were successfully prepared by a facile one-pot hydrothermal treatment in the presence of L-lysine, which acts as a ligand to control the nanocrystal growth and as a source of nitrogen and carbon. As-prepared nanocomposites were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), electron paramagnetic resonance (EPR) spectra, and N(2) adsorption-desorption analysis. The photocatalytic activities of the as-prepared photocatalysts were measured by the degradation of methyl orange (MO) under visible light irradiation at λ≥ 400 nm. The results show that N-TiO(2)/C nanocomposites increase absorption in the visible light region and exhibit a higher photocatalytic activity than pure TiO(2), commercial P25 and previously reported N-doped TiO(2) photocatalysts. We have demonstrated that the nitrogen was doped into the lattice and the carbon species were modified on the surface of the photocatalysts. N-doping narrows the band gap and C-modification enhances the visible light harvesting and accelerates the separation of the photo-generated electrons and holes. As a consequence, the photocatalytic activity is significantly improved. The molar ratio of L-lysine/TiCl(4) and the pH of the hydrothermal reaction solution are important factors affecting the photocatalytic activity of the N-TiO(2)/C; the optimum molar ratio of L-lysine/TiCl(4) is 8 and the optimum pH is ca. 4, at which the catalyst exhibits the highest reactivity. Our findings demonstrate that the as-obtained N-TiO(2)/C photocatalyst is a better and more promising candidate than well studied N-doped TiO(2) alternatives as visible light photocatalysts for potential applications in environmental purification.     

N-TiO2/Ti3C2复合材料的原位合成及其光催化性能

以钛碳化铝、氢氟酸、氟硼酸钠为原料，以尿素为氮源，通过简单的溶剂热反应，在高导电性的Ti3C2 MXenes（二维过渡金属碳化物）纳米片上原位生长氮元素掺杂的TiO2纳米片，合成了二维N-TiO2/Ti3C2光催化复合材料。采用X射线衍射仪、扫描电子显微镜、透射电子显微镜、X射线光电子能谱仪、紫外-可见漫反射光谱仪、光致发光光谱仪等对催化剂样品进行了结构表征。结果表明，在可见光照射下，N-TiO2/Ti3C2复合材料对罗丹明B（RhB）表现出较好的光催化降解性能，其降解速率是纯TiO2的8.41倍，在150min内，罗丹明B降解率达到96.3%。这主要是由于氮元素的掺杂缩小了TiO2的带隙，将光响应范围扩展到可见光区域。同时，TiO2纳米片的原位生长使其与具有优异电导率的Ti3C2 MXenes纳米片形成了紧密的接触界面，促进了光生载流子的分离和迁移。自由基捕获实验和电子自旋共振测试结果显示，•O2-和•OH是N-TiO2/Ti3C2光催化体系降解罗丹明B的主要活性物种。此外，N-TiO2/Ti3C2复合材料具有良好的稳定性和可重复利用性。     

晶相结构对二氧化钛氮掺杂类型及其光催化性能的影响

采用沉淀法制备不同晶型的TiO_2,采用微波法和氨气气氛焙烧法制备了氮掺杂纳米TiO_2,对其进行了XRD、XPS和UV-Vis表征,通过光催化性能的评价,考察晶型对氮掺杂TiO_2光催化活性的影响。结果表明,在TiO_2掺氮过程中,间隙氮与取代氮形式主要由制备方法决定,并不随晶型不同而变化。两种方法掺氮后对锐钛矿和金红石结构TiO_2的可见光光催化活性均有较大提高,但复合相结构的可见光光催化活性没有明显提高。     

N-TiO_2/RGO复合光催化剂的制备及其性能

用改进的Hummers法制得了氧化石墨烯,以Ti（SO4）2为钛源,氨水为氮源,在400℃煅烧下制备了锐钛矿型的氮元素掺杂的TiO2（N-TiO2）。利用溶液混合法将二者混合,再经水热处理法制备了不同质量复合比例的N-TiO2/RGO光催化剂。通过X射线衍射、Fourier变换红外光谱、扫描电子显微镜等对样品的组成与形貌进行了表征,并通过降解1×10–4mol/L亚甲基蓝溶液表征了各样品的光催化效率。结果表明：掺杂氮元素一定程度上提高了TiO2的光催化效能,与石墨烯的复合更进一步改善了N-TiO2光催化效能。     

Preparation, characterization and photocatalytic behavior of WO3-fullerene/TiO2 catalysts under visible light

WO3-treated fullerene/TiO2 composites (WO3-fullerene/TiO2) were prepared using a sol-gel method. The composite obtained was characterized by BET surface area measurements, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, and UV-vis analysis. A methyl orange (MO) solution under visible light irradiation was used to determine the photocatalytic activity. Excellent photocatalytic degradation of a MO solution was observed using the WO3-fullerene, fullerene-TiO2, and WO3-fullerene/TiO2 composites under visible light. An increase in photocatalytic activity was observed, and WO3-fullerene/TiO2 has the best photocatalytic activity; it may attribute to the increase of the photo-absorption effect by the fullerene and the cooperative effect of the WO3.     

氮掺杂TiO_2水热法制备及其光催化活性的研究

以钛酸四丁酯、尿素、无水乙醇为原料,采用水热合成方法制备了掺氮和不掺氮的二氧化钛前驱体。以250W高压汞灯为光源,达旦黄水溶液为活性评价体系,设计正交表研究了N-TiO2光催化实验的最佳条件。研究了N-TiO2对不同拟污染物的降解能力,分析了可见光条件下N-TiO2和TiO2光催化活性。     

硼氮共掺杂TiO2粉末制备及光催化活性研究

采用溶胶-凝胶法制备硼氮共掺杂TiO₂光催化剂,利用X射线衍射、X射线光电子能谱及紫外-可见光漫反射光谱手段对制备的催化剂进行表征。结果表明,硼和氮均以间隙方式进入TiO₂晶格中,形成Ti-O-B、Ti-O-N和Ti-O-B-N结构,提高了催化剂活性;B-N-TiO₂吸收带边明显红移,表明催化剂对可见光吸收增强。可见光降解甲基橙结果表明,B-N-TiO₂的活性明显高于B-TiO₂和N-TiO₂,说明硼氮共掺杂改性对提高TiO₂可见光活性具有协同作用。     

掺钒二氧化钛的可见光催化性能研究

制备高活性可见光响应型掺钒TiO2光催化剂,以荧光灯为光源,光催化降解亚甲基蓝为模型反应,对可见光下TiO2的催化活性进行评价。研究了掺钒TiO2制备方法、掺钒量及氧化剂对光催化氧化的影响。结果表明,溶胶-凝胶法制备的TiO2催化活性较高,且工序简单,钒离子掺杂均匀;掺钒能使TiO2具有可见光响应,最佳掺钒量为1%;外加氧化剂H2O2能提高掺钒TiO2催化活性。     

Comparison of two synthesis methods on the preparation of Fe,N-Co-doped TiO2 materials for degradation of pharmaceutical compounds under visible light

In this work, we report the synthesis, characterization and photocatalytic evaluation of visible light active iron-nitrogen co-doped titanium dioxide (Fe³⁺-TiO_2−xN_x) nanostructured catalyst. Fe³⁺-TiO_2−xN_x was synthesized using two different chemical approaches: sol-gel (SG) and microwave (MW) methods. The materials were fully characterized using several techniques (SEM, UV–Vis diffuse reflectance DRS, X-ray diffraction XRD, and X-ray photoelectron spectroscopy XPS). The photocatalytic activity of the nanostructured materials synthesized by both methods was evaluated for the degradation of amoxicillin (AMX), streptomycin (STR) and diclofenac (DCF) in aqueous solution. Higher degradation efficiencies were encountered for the materials synthesized by the SG method, for instance, degradation efficiencies values of 58.61% (SG) and 46.12% (MW) were observed for AMX after 240 min of photocatalytic treatment under visible light at pH 3.5. With STR the following results removal efficiencies were obtained: 49.67% (SG) and 39.90% (MW) at pH 8. It was observed the increasing of degradation efficiencies values at longer treatment periods, i.e., after 300 min of photocatalytic treatment under visible light, AMX had a degradation efficiency value of 69.15% (MW) at pH 3.5, DCF 72.3% (MW) at pH 5, and STR 58.49% (MW) at pH 8.