TiO2催化超声降解甲基橙溶液

采用经过处理后工业生产的TiO2作为催化剂,以超声降解甲基橙反应为模型,研究了各种因素对。TiO2催化超声降解的影响。研究表明,在TiO2催化剂作用下超声降解甲基橙的效果明显。TiO2催化剂用量在0．3～0．5g／L之间,超声波频率25kHz,输出功率1．0W／cm^2,pH=1．0时,甲基橙水溶液初始浓度为20mg／L的条件下,90min左右基本可全部降解,COD的去除率达到99．0％。     

Fe3+/TiO2/SiO2复合纳米微粒的合成及光催化降解NO-2

光降解;Fe3+/TiO2/SiO2复合纳米微粒的合成及光催化降解NO-2     

SO42-/TiO2-SiO2的制备及对甲基橙的光催化降解

0 引言 水中难降解有机物的治理已成为当今重要的环境问题,对新型高效水处理剂的需求也愈加迫切。多相光催化氧化已成为国内外治理污水的新技术,但常规二氧化钛半导体光催化剂的量子效率     

SiO2掺杂TiO2催化超声降解甲基橙溶液

采用实验室合成的SiO2掺杂TiO2作为催化剂,以甲基橙超声降解反应为模型,研究了各种因素对SiO2掺杂TiO2催化超声降解甲基橙的影响.结果表明在SiO2掺杂TiO2催化剂作用下超声降解甲基橙的效果明显优于非掺杂的锐钛矿型TiO2的催化效果.SiO2掺杂TiO2催化剂用量在0.5～1.0g/L之间,超声波频率25kHz,输出功率1.0W/cm2,pH为1.0～3.0时,在甲基橙水溶液初始浓度20mg/L的条件下,80min,降解率达到了98%以上,COD的去除率也达到了99.0%.因此,SiO2掺杂TiO2催化超声降解有机污染物的方法具有很好的应用前景.     

La3+-SiO2掺杂纳米TiO2的合成及其光催化降解甲基橙的研究

以三嵌段非离子表面活性剂P123为模板,采用水热法合成了La3+-SiO2掺杂纳米TiO2,通过X射线衍射(XRD)、红外光谱(FT-IR)、紫外-可见漫反射吸收光谱(DRS)等手段,考察了La3+-SiO2掺杂纳米TiO2的结构与光学特性.实验结果表明,La3+和SiO2掺杂使TiO2的晶粒在生长过程中受到阻碍.Ti-O-Si键和Ti-O-La键的形成抑制了金红石相的形成和晶粒长大,提高了TiO2的热稳定性,有利于获得高纯度锐钛矿相纳米TiO2.La3+-SiO2掺杂将TiO2的光响应范围拓宽至可见光区,提高了纳米TiO2的光催化性能.与纯纳米TiO2相比,La3+-SiO2掺杂纳米TiO2光催化降解甲基橙的性能显著提高.     

Cu(Ⅱ)/TiO2/H2O2联合体系中甲基橙的太阳光催化降解

以钛酸四丁酯[Ti(OC4H9)4]为原料通过回流水解,制备了过渡金属Cu(Ⅱ)离子掺杂的TiO2光催化剂.通过TG DTA,IR,XRD对其进行了表征.结果表明:未经热处理的Cu(Ⅱ)/TiO2粉体为锐钛矿和板钛矿的混合晶型.在H2O2存在,太阳光照射下,甲基橙在该悬浮体系中迅速褪色降解,5min内降解率达90%以上.同时研究了pH值、H2O2浓度、甲基橙用量、光照条件、分散方式等对光催化剂活性的影响.     

TiO2光催化降解聚乙烯薄膜

TiO2光催化降解聚乙烯薄膜;纳米TiO2;固相光催化;聚乙烯塑料;降解     

银促进的TiO2光催化降解甲基橙

 采用溶胶-凝胶和水热协同法制备了不同Ag含量的负载型Ag-TiO2样品,这些样品具有较大的比表面积和较小的粒径. 适量负载金属银后的TiO2在紫外及可见光下的光催化活性均得到提高. 银在TiO2上的最佳负载量为0.15%, 过高的负载量反而会降低TiO2光催化降解甲基橙的活性. 由于反应机理的不同,银负载对TiO2可见光下催化活性的提高要明显高于对其紫外光下催化活性的提高. 在可见光照射下,从激发态染料注入到TiO2导带的电子迅速转移到了Ag原子簇, Ag原子簇通过促进电荷分离抑制了电子和染料正离子自由基的复合,从而促进了光催化过程. 研究结果表明,有效地促进电荷分离以及激发态电子和氧气分子的反应是提高染料敏化光催化活性的关键.     

Fe2O3掺杂TiO2薄膜对甲基紫溶液光催化降解

光降解;Fe2O3掺杂TiO2薄膜对甲基紫溶液光催化降解     

纳米尺度分散的TiO2光催化降解甲醛的机理

纳米TiO2具有小尺寸效应,表面效应和宏观量子隧道效应等[1],广泛用于防水处理、空气净化、抗菌防霉等方面。本文对其能带结构及其消除甲醛的性能及机理进行分析。1　纳米TiO2光催化剂1 1　制备与表征以四氯化钛为主要原料,氨水、醇类化合物、盐酸等为主要反应助剂,采用亚稳态氯化法制备工艺,用相应的溶胶反应形成溶胶液体,低于100℃加热该液体,除去多余的水分,得到溶胶-凝胶体。过滤所得溶胶-凝胶体,并用蒸馏水反复洗涤数次,使其pH呈中性。将洗涤后的溶胶-凝胶体进行真空干燥,得到白色微粉,1000℃高温煅烧,将煅烧后得到的纳米TiO2基…     

Pd/TiO2 Nanospheres with Three-dimensional Hyperstructure for Enhanced Photodegradation of Organic Dye

Pd/TiO2 nanospheres assembled from nanorods with three-dimensional hyperstructure for enlianced photodegradation of organic dye was prepared by a sample solvothemial method. Further, it was used for degradation of methyl orange(MO) under the illumination of visible-light(simulated).The results show that Pd/TiO2 with 2%(mass fraction) Pd exhibits the noticeable activity in photodegrading of MO.The detailed analysis shows that this enhancement is attributed to the reduction of the rate of electron-hole recombination and surface plasmon resonance of Pd. The high activity and good stability of the obtained Pd/TiO2 nano spheres make it a promising photocatalyst for solving the environmental pollution problems.     

不同晶相TiO2负载Cu2O催化甲醛乙炔化反应

分别以金红石相和锐钛矿相TiO₂为载体, 采用液相还原-沉积法制备了Cu₂O/TiO₂催化剂. 采用氮气物理吸附-脱附(N₂-physisorption)实验、 氢气程序升温还原(H₂-TPR)、 X射线衍射(XRD)、 X射线光电子能谱(XPS)、 CO红外光谱(CO-IR)及高分辨透射电子显微镜(HRTEM)等技术, 研究了不同晶相TiO₂载体对Cu₂O/TiO₂结构及其催化甲醛乙炔化反应性能的影响. 结果表明, 以金红石相TiO₂为载体的催化剂炔化活性明显高于以锐钛矿相TiO₂为载体的催化剂, 原因在于金红石相TiO₂主要暴露(110)晶面, 其与铜物种的配位环境及较高的空位密度形成了更多的Cu—O—Ti结构物种, 表现为Cu₂O与TiO₂之间强的相互作用. 这导致Cu₂O高效转变为乙炔亚铜活性物种, 并保持了较高的分散度与稳定性, 抑制了过度还原物种金属Cu的生成, 进而使催化剂表现出较高的催化性能.     

Highly Ordered TiO2 Nanotubes for Electrochemical Sensing of Hair Dye Basic Brown 17

Self‐organized Ti/TiO₂ nanotubular array electrodes were prepared by electrochemical anodization and used to monitor the reduction of the hair dye basic brown 17 (BB17) at a potential of ?0.60 V vs. Ag/AgCl. Analytical curves were obtained from 1.0×10^?6 to 8.0×10^?5 mol L^?1 with a detection limit of 1.3×10^?7 mol L^?1 by using the best experimental conditions, linear scan voltammetry at pH 6, scan rate=60 mV s^?1, and accumulation time=5 min. The detection system performance was not interfered by other hair dyes and successfully used to determine the dye in tap water samples.     

Template Synthesis and Characterization of Cu2O/TiO2 Coaxial Nanocable for Photocatalysis

Coaxial nanocable consisted of p-type Cu₂O nanowires and n-type TiO₂ nanotubes arrays was prepared in the porous anodic aluminum oxide(AAO) template via the sol-gel method and subsequent electrodeposition method. X-ray diffraction analysis identified an anatase structure of the TiO₂ nanotubes and cubic structure of the Cu₂O nanowires. The obtained samples were also characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and energy dispersive X-ray spectroscopy(EDS). The diffrence of open circuit potential of the coaxial nanocable electrode was larger than that of the TiO₂ nanotubes electrode under ultraviolet illumination, which means doping with Cu₂O could improve the photovoltage effectively. Meanwhile, nanocable arrays exhibited a high activity for photodegrading Rhodamine B under Xe lamp irradiation and the photocatalysis degradation efficiency was up to 98.69% after degradation for 7 h. The enhanced photocatalytic activity could be attributed to the high migration efficiency of photoinduced electrons, which may suppress the charge recombination effectively.     

Simultaneous Tuning Band Gaps of Cu2O and TiO2 to Form S-Scheme Hetero-Photocatalyst

Photocatalytic Z or S scheme merits higher redox potentials and faster charge separation. However, heterostructure photocatalysts with band gaps of bulk materials often have a type I band structure leading to poor photocatalytic activity. In view of this, we report simultaneous tuning of band gaps of Cu₂O and TiO₂, where quantum dot Cu₂O nanoparticles were formed on doped TiO₂ with Ti³⁺. The reduced size of Cu₂O made its conduction band more negative, whereas the introduction of Ti³⁺ made the absorption edge red shift to the visible light region. The as-formed heterostructure enabled an S-Scheme mechanism with remarkable activity and stability for visible light photodegradation of 4-chlorophenol (4-CP). The as-obtained photocatalysts’ activity demonstrated ca. 510-fold increase as compared to individual ones and a mechanical blend. The as-obtained photocatalysts maintained over 80 % for 5 cycles and 2 months exposure to O₂ did not decrease the degradation rate. ESR characterization and scavenger experiments proved the S-Scheme mechanism.     

新型复合电极对偶氮染料分子的光催化降解

介绍了具有合成H2O2和光催化性能的双功能新型复合电极,并用X射线衍射、扫描电镜等方法进行了表征.双功能复合电极是将TiO2光催化剂负载在活性碳(AC)和具有合成H2O2性能的新型载体空气电极上形成的.在复合电极作阴极的光反应器中,* OH和TiO2光催化剂的存在实现了光化学氧化与光催化氧化在同一电极/溶液界面上的联合作用.实验结果表明,复合电极对提高偶氮染料分子活性艳红(K-2BP)的氧化降解速度起了重要作用,仅反应3 min,脱色率可达49%;反应80 min,偶氮染料分子COD去除率可达47%.     

空气电极改性TiO2光催化剂的研究

将TiO2/C光催化剂负载在具有合成H2O2性能的空气电极上形成双功能新型复合电极.TiO2/C光催化层的微多孔特性使新型载体保持了高效合成H2O2的优势,J=15mA/cm2时,电流效率达到82%.新型载体又为TiO2/C光催化剂获得了阳极偏压,有利于将光生电子迅速导入载体,减少了光生载流子的复合.在新型光催化体系中,光化学氧化作用与光催化氧化作用有机地统一在同一电极/溶液界面附近,造成了该界面的强氧化环境,从而使有机分子的氧化降解速度得到显著提高.     

脉冲沉积制备Cu_2O/TiO_2纳米管异质结的可见光光催化性能

在用阳极氧化法制备有序排列TiO2纳米管阵列薄膜的基础上,引入脉冲沉积工艺,成功实现了均匀、弥散分布的Cu2O纳米颗粒修饰改性TiO2纳米管阵列,形成Cu2O/TiO2纳米管异质结复合材料.利用场发射扫描电镜(FESEM)、场发射透射电镜(FETEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和紫外-可见漫反射光谱(UV-Vis DRS)对样品进行表征,重点研究了Cu2O/TiO2纳米管异质结的光电化学特性和对甲基橙(MO)的可见光催化降解性能.结果表明,Cu2O纳米颗粒均匀附着在TiO2纳米管阵列的管口和中部位置,所制备的Cu2O/TiO2纳米管异质结具有高效的可见光光催化性能;在浓度为0.01 mol?L-1的CuSO4溶液中制得的Cu2O/TiO2纳米管异质结表现出最好的电化学特性和光催化性能;另外,对Cu2O纳米颗粒影响光催化活性的机理进行了讨论.     

Fe3+掺杂TiO2光催化降解聚乙烯薄膜的研究

以快速溶胶-凝胶法制备了纳米TiO₂光催化剂，并用Fe³⁺对其掺杂改性，在室温条件下, 用于固相光催化降解聚乙烯(PE)包装薄膜的研究. 对催化剂和薄膜进行了X衍射分析(XRD)、傅立叶红外光谱分析(FT-IR)、扫描电子显微镜(SEM)形貌观察. 结果表明， 60 W紫外光辐射240 h后， PE失重为8.43%, 锐钛矿型纳米TiO₂光催化剂使PE失重30.66%；用Fe³⁺掺杂后，0.5%Fe₂O3/TiO₂、1.0%Fe₂O₃/TiO₂和2.0%Fe₂O3/TiO₂分别使PE失重35.91%、20.72%和13.30%. 光催化剂加速了PE的失重，碳链的断裂和光氧化腐蚀，在薄膜表面形成大量的坑洞，降解产物中的小分子量的石蜡含量明显增高. Fe³⁺掺杂有一个最佳量， 0.5%Fe₂O3/TiO₂光催化降解PE的活性最高.