钙钛矿氧化物H_(1.9)K_(0.3)La_(0.5)Bi_(0.1)Ta_2O_7和Pt/WO_3组成的Z体系下完全光解水性能

以质子化层状钙钛矿氧化物H1.9K0.3La0.5Bi0.1Ta2O7(HKLBT)作为产氢催化剂,Pt/WO3作为产氧催化材料进行Z型体系下完全分解水反应.考察了不同载流子传递介质及不同载流子浓度对反应活性的影响.结果表明,以Fe2+/Fe3+为载流子传递介质时可以实现水的完全分解(H2/O2体积比为2:1),8 mmol·L-1的FeCl3作为初始载流子传递介质时,产氢、产氧活性分别为66.8和31.8μmol·h-1,氢氧体积比为2.1:1.受光催化材料对载流子传递介质氧化还原速度的限制,过高的载流子传递介质浓度并不能提高光催化活性.     

光催化全解水助催化剂的设计与构建

能源和环境危机是当今社会面临的两大关键课题,利用太阳光驱动化学反应、将太阳能转化为化学能是解决上述问题的重要措施。通过光催化分解水是直接利用太阳能生产氢燃料的有效策略。光催化水分解过程可以分为三个基元步骤:光吸收、电荷分离与迁移、以及表面氧化还原反应。助催化剂可有效提高电荷分离效率、提供反应活性位点并抑制催化剂光腐蚀的发生,进而提高水分解效率。助催化剂也可以通过活化水分子以提高表面氧化还原动力学,进而提升整体光催化反应的太阳能转换效率。本文综述了助催化剂在光催化反应中的重要作用以及目前常用的助催化剂类型,详细说明了在光催化全解水过程中双助催化剂体系的构建及作用机理,并根据限制全解水的关键因素提出了新型助催化剂的设计策略。     

C/Cr2O3/TiO2复合材料的制备及其光催化性能研究

本文以制革含铬革屑为原材料,基于矿物鞣剂复鞣的原理,将Ti(IV)均匀、稳定地负载到含铬革屑上,在氮气氛围下,经高温热解制备得到C/Cr₂O₃/TiO₂光催化剂,并研究了其对四环素(TC)的光催化降解效果及机理。结果表明,C/Cr₂O₃/TiO₂光催化剂具有明显的介孔结构,比表面积较大,为277.47 m²·g^-1,Cr₂O₃和TiO₂已实现复合并负载在生物炭(C)上。通过光催化降解发现,在模拟自然光照下,当催化剂用量为0.04 g,TC初始浓度为50 mg·L^-1,溶液pH为2时,TC的去除率可高达99.99%。结合自由基捕获实验发现,C/Cr₂O₃/TiO₂光催化剂对TC的降解作用主要依靠反应体系中产生的大量·O₂^-,·OH和h⁺。     

SnO_2/TiO_2纳米管复合光催化剂的性能及失活再生

基于微波水热法和微乳液法合成SnO2/TiO2纳米管复合光催化剂.通过X射线衍射(XRD)、配有能量色散X射线光谱仪(EDX)的透射电镜(TEM)和电化学手段对光催化剂进行表征.以甲苯为模型污染物,考察光催化剂在紫外光(UV)和真空远紫外光(VUV)下的性能及失活再生.结果表明,SnO2/TiO2纳米管复合光催化剂形成三元异质结(锐钛矿相TiO2(A-TiO2)/金红石相TiO2(R-TiO2)、A-TiO2/SnO2和R-TiO2/SnO2异质结),促使光生电子-空穴对的有效分离,提高光催化活性.SnO2/TiO2表现出最佳的光催化性能,UV和VUV条件下的甲苯降解率均达100%,CO2生成速率(k2)均为P25的3倍左右.但由于UV光照矿化能力不足,中间产物易在催化剂表面累积.随着UV光照时间的增加,SnO2/TiO2逐渐失活,20 h后k2由138.5 mg·m-3·h-1下降到76.1 mg·m-3·h-1.利用VUV再生失活的SnO2/TiO2,过程中产生的·OH、O2-·、O(1D)、O(3P)、O3等活性物质可氧化吸附于催化剂活性位的难降解中间产物,使催化剂得以再生,12 h后k2恢复到143.6 mg·m-3·h-1.UV和VUV的协同效应使UV降解耦合VUV再生成为一种可持续的光催化降解污染物模式.     

新型核壳Ag@AgSeX纳米粒子析氢助剂:原位表面硒化以提升TiO2的光催化产氢活性

纯相光催化材料的产氢性能主要受限于较低的电荷分离效率和缓慢的界面催化反应速率.表面负载助催化剂因其能够实现快速转移光生电子和提供界面催化活性中心被认为是促进电荷分离和提升界面催化反应的有效手段.贵金属类材料,尤其是金属铂(Pt),被认为是光催化产氢领域的理想助剂,但储量低和价格昂贵严重制约了其大规模实际应用.因此,发展...     

微波辅助快速制备2D/1D ZnIn2S4/TiO2 S型异质结及其光催化制氢性能

The threat and global concern of energy crises have significantly increased over the last two decades. Because solar light and water are abundant on earth, photocatalytic hydrogen evolution through water splitting has been considered as a promising route to produce green energy. Therefore, semiconductor photocatalysts play a key role in transforming sunlight and water to hydrogen energy. To date, various photocatalysts have been studied. Among them, TiO₂ has been extensively investigated because of its non-toxicity, high chemical stability, controllable morphology, and high photocatalytic activity. In particular, 1D TiO₂ nanofibers (NFs) have attracted increasing attention as effective photocatalysts because of their unique 1D electron transfer pathway, high adsorption capacity, and high photoinduced electron–hole pair transfer capability. However, TiO₂ NFs are considered as an inefficient photocatalyst for the hydrogen evolution reaction (HER) because of their disadvantages such as a large band gap (~3.2 eV) and fast recombination of photoinduced electron–hole pairs. Therefore, the development of a high-performance TiO₂ NF photocatalyst is required for efficient solar light conversion. In recent years, several strategies have been explored to improve the photocatalytic activity of TiO₂ NFs, including coupling with narrow-bandgap semiconductors (such as ZnIn₂S₄). Recently, microwave (MW)-assisted synthesis has been considered as an important strategy for the preparation of photocatalyst semiconductors because of its low cost, environment-friendliness, simplicity, and high reaction rate. Herein, to overcome the above-mentioned limiting properties of TiO₂ NFs, we report a 2D/1D ZnIn₂S₄/TiO₂ S-scheme heterojunction synthesized through a microwave (MW)-assisted process. Herein, the 2D/1D ZnIn₂S₄/TiO₂ S-scheme heterojunction was constructed rapidly by using in situ 2D ZnIn₂S₄nanosheets decorated on 1D TiO₂ NFs. The loading of ZnIn₂S₄ nanoplates on the TiO₂ NFs could be easily controlled by adjusting the molar ratios of ZnIn₂S₄ precursors to TiO₂ NFs. The photocatalytic activity of the as-prepared samples for water splitting under simulated solar light irradiation was assessed. The experimental results showed that the photocatalytic performance of the ZnIn₂S₄/TiO₂ composites was significantly improved, and the obtained ZnIn₂S₄/TiO₂ composites showed increased optical absorption. Under optimal conditions, the highest HER rate of the ZT-0.5 (molar ratio of ZnIn₂S₄/TiO₂= 0.5) sample was 8774 μmol·g^-1·h^-1, which is considerably higher than those of pure TiO₂ NFs (3312 μmol·g^-1·h^-1) and ZnIn₂S₄nanoplates (3114 μmol·g^-1·h^-1) by factors of 2.7 and 2.8, respectively. Based on the experimental data and Mott-Schottky analysis, a possible mechanism for the formation of the S-scheme heterojunction between ZnIn₂S₄ and TiO₂ was proposed to interpret the enhanced HER activity of the ZnIn₂S₄/TiO₂heterojunctionphotocatalysts.      

不同半导体体系中磷化镍光催化甲酸分解的助催化作用

研究了在不同的半导体体系(TiO₂, CdS和C₃N₄)中, Ni₂P光催化甲酸(HCOOH)分解制氢的助催化效应. 作为助催化剂, Ni₂P与3种半导体形成的复合光催化剂均表现出良好的HCOOH分解制氢活性. Ni₂P/TiO₂, Ni₂P/CdS, Ni₂P/C₃N₄ 3种光催化剂最优的产氢活性分别为41.69, 22.45和47.67 μmol·mg^-1·h^-1, 分别为纯TiO₂, CdS和C₃N₄的3.8倍、 10倍和210倍, 表明Ni₂P在光催化HCOOH分解制氢体系中具有普适性. 研究了光催化HCOOH分解制氢的机理, Ni₂P的加入使光生电子从半导体转移至Ni₂P, 提高了光生电子-空穴对的分离效率; Ni₂P还促进了活性物种·OH的生成, 提高了光催化HCOOH分解的产氢速率.     

Se掺杂对单层MoS2电子能带结构和光吸收性质的影响

基于密度泛函理论的第一性原理方法,计算了Se掺杂单层MoS₂能带结构和光吸特性,并分析了对其光解水性质的影响。结果表明：本征单层MoS₂为直接带隙结构,禁带宽度为1.740 eV,导带底电位在H⁺/H₂还原势之上0.430 eV,价带顶电位在O₂/H₂O的氧化势之下0.080 eV,具有可见光催化分解水的能力,但氧化和还原能力不均衡,导致单层MoS₂作为光催化剂分解水的效率不高。通过Se掺杂计算发现,单层MoS₂的禁带宽度变为1.727 eV,相应的光吸收谱变化幅度几乎不变,且体系的形成能较低,表明其热力学稳定性良好。然而,导带底电位调整到H⁺/H₂还原势之上0.253 eV,价带顶电位处于O₂/H₂O的氧化势之下0.244 eV,平衡了氧化与还原能力,单层MoS₂可见光催化分解水的效率得到提高。     

简单浸渍法制备纳米CuO/TiO2及其光催化剂活性

以Cu(NO₃)₂·3H₂O和P25为前躯体,通过简单浸渍法制备了CuO/TiO₂光催化剂,利用N₂物理吸附、XRD、TEM、UV-vis漫反射光谱分析了催化剂的结构特性。研究了Cu组分的负载量、催化剂在反应液中的分散量、催化剂焙烧温度、反应液中甲醇浓度对CuO/TiO₂光催化反应产氢活性的影响,并考察了催化剂的稳定性,提出了该体系光催化反应的机理。结果表明,Cu的适宜负载量为2.0%~7.5%(质量分数),在Cu质量分数2.0%、催化剂焙烧温度350℃、甲醇的体积浓度为10%、催化剂分散量为1.0 g/L时,产氢活性可达到1 022 μmol/(h·g),并且该催化剂具有较好的稳定性。     

超薄骨架有序介孔CdS/NiS的制备及光催化产氢性能

采用有序介孔氧化硅为硬模板, 通过纳米浇筑法制备了由螺旋骨架构建的有序介孔硫化镉(CdS)光 催化材料. 该光催化材料具有约5 nm厚的超薄骨架和大的比表面积(238 m²/g), 能有效缩短光催化反应中 光生电荷迁移到表面进行反应的距离并同时提供更多的反应活性位点, 从而增强光催化性能. 通过原位化学沉积法将不同量的助催化剂硫化镍(NiS)沉积到有序介孔CdS表面, 得到了一系列超薄骨架有序介孔CdS/NiS复合光催化材料. 可见光照射下的光催化产氢活性测试结果表明, 负载适量NiS的有序介孔CdS具有显著增强的光催化产氢活性(3.84 mmol?h^-1?g^-1), 约为负载相同量NiS的普通商业化CdS材料(0.22 mmol?h^-1?g^-1)的17.5倍.     

煅烧温度对Mn/TiO_2催化剂催化NO氧化活性的影响

以浸渍在二氧化钛上的锰基催化剂为对象,研究了制备过程中煅烧温度对锰基催化剂催化NO氧化活性的影响。结果表明,较低的煅烧温度有利于提高Mn/TiO2催化剂对于NO氧化的催化效率。利用X射线粉末衍射(XRD)、场发射扫描电子显微镜(FESEM)、X射线光电子能谱(XPS)、H2程序升温还原(H2-TPR)和O2程序升温脱附(O2-TPD)等表征手段研究了煅烧温度影响Mn/TiO2催化剂催化活性的作用机理。结果表明,在NO氧化过程中发挥主要作用的是Mn2O3,较低的煅烧温度有利于提高Mn2O3在锰氧化物中所占的比例,同时增加锰氧化物在载体表面的分散度,从而改善催化剂活性;当煅烧温度超过500℃时,催化剂会发生烧结,载体TiO2的晶形开始由锐钛型向金红石型转变,Mn2O3也从非晶相向晶相转变。H2-TPR和O2-TPD测试结果表明,低温煅烧有利于提高催化剂的还原性能和表面化学吸附态O2-的脱附性能,良好的还原性能和脱附性能的相互作用使催化剂表面的氧有较好的移动能力,从而促进催化剂的活性。     

Synthesis of Holey Graphitic Carbon Nitride with Highly Enhanced Photocatalytic Reduction Activity via Melamine-cyanuric Acid Precursor Route

In this work, holey graphitic carbon nitride(HCN) was prepared by one-step thermal polymerization of hydrothermal product of melamine and then loaded with Ni/MoO₂(NiMo) cocatalyst obtained by NaBH₄ reduction process. The obtained material was used for photocatalytic production of H₂ from water reduction and H₂O₂ production from O₂ reduction. The best photocatalyst(1% NiMo/HCN) exhibited a H₂ evolution rate of 8.08 μmol/h while no H₂ was detected over 1% NiMo-modifed bulk g-C₃N₄(BCN) under visible light illumination. Moreover, this rate is 1.7 times higher than that of 1% Pt-modified HCN. The 1% NiMo/HCN catalyst also exhibited the highest H₂O₂ production activity with a value of 6.13 μmol/h. Such enhancement was ascribed to the efficient charge carrier separation and migration, which were promoted by the large specific surface area and pore volume of HCN and the synergy between MoO₂ and Ni. The proposed method to obtain HCN is expected to open up new ways in development of highly-active HCN-based photocatalysts for photocatalytic reduction reactions.     

合理设计具有空间分离催化位点的中空立方体顺序材料作为高效的全解水光催化剂

通过精细的纳米结构和化学组成控制,开发高效的全解水纳米光催化剂是一项具有挑战性的任务.此外,在光催化水氧化的半反应过程中,抑制纳米材料严重光腐蚀也是一项艰巨的任务,需要有效地提高纳米材料光生空穴转移的动力学.为此,本文通过可控的化学反应,设计制备了具有空间催化活性位点分布的Co-MnO₂@CdS/CoS中空立方体顺序材料,并用作可见光催化全解水催化剂.采用MOFs作为自模板,经过连续的阴离子交换和阳离子交换反应,将Co掺杂的氧化助催化剂(纳米片Co-MnO₂)和还原助催化剂(纳米粒子CoS)同时整合到中空的立方体CdS纳米材料中,使得超薄的二维纳米片Co-MnO₂与立方体的内部界面均匀接触,能够有效地提高空穴的转移效率.同时,CoS纳米粒子均匀分散在CdS纳米材料的壁上,能够有效地转移光生电子,从而提高光生电子-空穴对的分离效率.实验测试表明,Co-MnO₂@CdS/CoS中空立方体顺序材料可以为表面氧化-还原反应提供丰富的反应活性位点,同时有助于提高CdS纳米材料光生电子-空穴对的分离和迁移效率.特别是分散在CdS中空立方体壁面上的CoS纳米颗粒被确定为加速氢气生成的还原型助催化剂,能够促进水中氢离子生成氢气;而附着在CdS中空立方体内壁上的Co-MnO₂纳米片被确定为促进氧演化动力学的氧化型助催化剂,能够促进水生成氧气.因此,在本实验中,得益于理想的纳米结构和化学组成方面的优势,Co-MnO₂@CdS/CoS纳米立方体显示了高效的光催化全解水性能:在没有贵金属作为助催化剂存在时,它显示了很好的整体光催化水分解效率(735.4(H₂)和361.1(O₂)μmol h^-1 g^-1),超过了大多数文献报道的CdS基催化剂光解水效率.此外,以420 nm单波长光为入射光,进行了量子效率(AQE)测试,最优的Co-MnO₂@CdS/CoS纳米材料的表观AQE达1.32%.本文合成的顺序材料为构筑具有活性位点空间分布的高效全解水催化剂提供了新的思路.     

三维网状Dy3+:YVO4/TiO2复合纤维的制备及光催化产氢性能

以电纺TiO₂纳米纤维为基质, 柠檬酸为软模板, 采用一步水热法制备了具有三维立体网状结构的稀土Dy ³⁺掺杂YVO₄/TiO₂复合纤维. 通过X射线衍射、 扫描电子显微镜、 X射线光电子能谱、 N₂吸附-脱附、 紫外-可见漫反射光谱及荧光光谱等手段对材料的组成、 表面形貌和性能进行表征, 以光分解水产氢实验考察其光催化活性. 结果表明, Dy ³⁺∶YVO₄纳米枝与TiO₂纳米纤维相互交联构筑的纳米纤维网具有大比表面积, 可提供更多活性位点, 改善了多相光催化反应的传递过程; 稀土Dy ³⁺掺杂的YVO₄与TiO₂复合形成异质结相互促进, 在拓宽光谱响应范围、 提高太阳光利用率的同时使光生电子-空穴对得到较好分离, 从而提高了样品的光催化活性. 模拟太阳光照射下, Dy ³⁺∶YVO₄/TiO₂复合纤维光催化产氢速率达到8.63 mmol· h ^-1·g ^-1, 是纯TiO₂纳米纤维的10倍.     

羧基功能化石墨烯增强TiO2光催化产氢性能

The use of semiconductor photocatalysts (CdS, g-C₃N₄, TiO₂, etc.) to generate hydrogen (H₂) is a prospective strategy that can convert solar energy into hydrogen energy, thereby meeting future energy demands. Among the numerous photocatalysts, TiO₂ has attracted significant attention because of its suitable reduction potential and excellent chemical stability. However, the photoexcited electrons and holes of TiO₂ are easily quenched, leading to limited photocatalytic performance. Furthermore, graphene has been used as an effective electron cocatalyst in the accelerated transport of photoinduced electrons to enhance the H₂-production performance of TiO₂, owing to its excellent conductivity and high charge carrier mobility. For an efficient graphene-based photocatalyst, the rapid transfer of photogenerated electrons is extremely important along with an effectual interfacial H₂-production reaction on the graphene surface. Therefore, it is necessary to further optimize the graphene microstructures (functionalized graphene) to improve the H₂-production performance of graphene-based TiO₂ photocatalysts. The introduction of H₂-evolution active sites onto the graphene surface is an effective strategy for the functionalization of graphene. Compared with the noncovalent functionalization of graphene (such as loading Pt, MoS_x, and CoS_x on the graphene surface), its covalent functionalization can provide a strong interaction between graphene and organic molecules in the form of H₂-evolution active sites that are produced by chemical reactions. In this study, carboxyl-functionalized graphene (rGO-COOH) was successfully modified via ring-opening and esterification reactions on the TiO₂ surface by using an ultrasound-assisted self-assembly method to prepare a high-activity TiO₂/rGO-COOH photocatalyst. The Fourier transform infrared (FTIR) spectra, X-ray photoelectron spectroscopy (XPS), and thermogravimetric (TG) curves revealed the successful covalent functionalization of GO to rGO-COOH by significantly enhanced ―COOH groups in FTIR and increased peak area of carboxyl groups in XPS. A series of characterizations, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), XPS, and UV-Vis adsorption spectra, were performed to demonstrate the successful synthesis of TiO₂/rGO-COOH photocatalysts. The experimental data for the hydrogen-evolution rate showed that the TiO₂/rGO-COOH displayed an extremely high hydrogen-generation activity (254.2 μmol∙h⁻¹∙g⁻¹), which was 2.06- and 4.48-fold higher than those of TiO₂/GO and TiO₂, respectively. The enhanced photocatalytic activity of TiO₂/rGO-COOH is ascribed to the carboxyl groups of carboxyl-functionalized graphene, which act as effective hydrogen-generation active sites and enrich hydrogen ions owing to their excellent nucleophilicity that facilitates the interfacial hydrogen production reaction of TiO₂. This study provides novel insights into the development of high-activity graphene-supported photocatalysts in the hydrogen-generation field.      

MoS_2/TiO_2复合催化剂的制备及其在紫外光下的光催化制氢活性

为了研究复合光催化剂在光催化中的制氢效率,采用水热法制备了Mo S2纳米片,然后通过水热法在Mo S2纳米片上负载了TiO_2纳米颗粒,形成了Mo S2/TiO_2异质结复合催化剂。采用冷场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、紫外-可见吸收光谱(UV-Vis)、拉曼光谱(Raman),X射线光电子能谱(XPS)对材料的结构和光学性能表征并进行分析。通过光催化制氢测试对光催化剂进行评价,实验结果表明,在波长为365 nm的紫外光照射下,最高光催化制氢速率为1004μmol·h-1·g-1,对应的催化剂的Mo S2含量为30%,其催化速率远大于单一的Mo S2和TiO_2,表明Mo S2/TiO_2复合催化剂在紫外光照下能显著提高光催化产氢性能。基于Mo S2/TiO_2复合光催化剂优越的光催化产氢性能,本文对复合光催化剂的产氢机理做了研究和分析。     

碳包覆Pd/TiO2光催化产氢协同胺类选择性氧化合成亚胺(英文)

负载型金属纳米催化剂由于其优异的光催化性能,被广泛应用于光催化产氢协同胺类氧化偶联合成高附加值亚胺体系。但在反应过程中,金属表面对H原子和亚胺表现出较强的吸附能力,导致了亚胺易于发生自氢化反应而生成仲胺,显著降低了亚胺的选择性。在本文中,我们证实了在Pd/Ti O₂表面构建超薄碳层(Pd/Ti O₂@C)是一种解决上述问题的有效策略。在Pd/Ti O₂表面构筑的超薄碳层可以有效调控H原子和亚胺在其表面的吸附行为,避免了光催化氧化偶联过程中亚胺的自氢化。因此,Pd/Ti O₂@C光催化剂在光催化产氢协同胺类选择性氧化合成亚胺体系中展现出优异的亚胺选择性。本研究提供了一种便捷有效的策略推动负载型金属纳米催化剂在光催化产氢协同合成高附加值产物体系中的应用。     

原位光沉积制备Z型α-Fe2O3/g-C3N4异质结及其可见光驱动光解水产氢性能

采用原位光沉积-煅烧法制得了Z型α-Fe₂O₃/g-C₃N₄异质结复合光催化剂。分别采用透射电子显微镜、X射线衍射、X射线光电子能谱、紫外可见漫反射光谱、荧光光谱以及电化学测试对样品进行了表征,并考察了可见光下光解水产氢活性。结果表明:当α-Fe₂O₃的负载量为2.9%时,α-Fe₂O₃/g-C₃N₄复合光催化剂具有最优的产氢催化活性,产氢速率高达1841.9μmol·g^-1·h^-1,约为g-C₃N₄的3.3倍。光催化性能的提高主要归因于3方面:(1)高温煅烧过程中α-Fe₂O₃的形成,有效促进了氮化碳片层的热剥离,增大了比表面积,从而为光催化反应提供了更多反应活性位;(2)超细α-Fe₂O₃颗粒(5~8 nm)高度均匀地分散在g-C₃N₄表面,并且与其紧密结合,形成了高质量的Z型异质结;(3)Z型异质结不仅有效抑制地了光生载流子的复合,同时极大地保留了g-C₃N₄导带电子的强还原性和α-Fe₂O₃价带空穴的强氧化性。     

耐高温核/壳结构TiO2/SiO2复合气凝胶的制备及其光催化性能

以钛酸四丁酯为源, 采用苯胺-丙酮原位生成水溶胶-凝胶法, 在乙醇超临界干燥过程中用部分水解的钛醇盐和硅醇盐对TiO₂凝胶进行超临界修饰制备了具有核/壳纳米结构的块体TiO₂/SiO₂复合气凝胶. 制备的复合气凝胶具有优异的机械性能, 其杨氏模量可达4.5 MPa. 复合气凝胶同时具有极好的高温热稳定性. 经过1000 ℃热处理后, 线性收缩由纯TiO₂气凝胶的31%降至复合气凝胶的10%, 且比表面积由纯TiO₂气凝胶的31 m²·g^-1提升至复合气凝胶的143 m²·g^-1. 此外, 该复合气凝胶经1000 ℃热处理后具有优异的光催化降解亚甲基蓝的性能. 其优异的光催化性能得益于TiO₂/SiO₂复合气凝胶1000 ℃处理后高的比表面积和小的颗粒尺寸. 优良的耐热性能、力学性能和光催化性能使获得的具有核/壳纳米结构的TiO₂/SiO₂复合气凝胶在光催化领域具有良好的应用前景.     

Sn4+掺杂对TiO2纳米颗粒膜光催化降解苯酚活性的影响

金属离子掺杂能改善TiO2纳米微粒光催化活性,在光降解大气和水污染物的研究中,已引起人们的重视[1,2].实验证明,掺杂物的浓度、掺杂离子的分布、掺杂能级与TiO2能带匹配程度、掺杂离子d电子的组态、电荷的转移和复合等因素对催化剂的光催化活性有直接影响[3].Kamat等[4]曾利用TiO2颗粒与SnO2颗粒混合制膜,使光催化剂活性得到提高.但Sn4+掺杂TiO2用于光催化剂尚少见报道.本文采用等离子体化学气相沉积法(PECVD)[5]制备了Sn4+离子掺杂的TiO2纳米颗粒膜催化剂(TiO2-Sn),考察了其对苯酚的光催化降解活性,讨论了Sn4+离子的掺杂方式及光催化活性提高的机理.