硫酸盐修饰的含钛高炉渣光催化还原Cr(Ⅵ)

采用高能球磨法,在300℃煅烧2 h合成了具有钙钛矿型的硫酸盐修饰的含钛高炉渣(sulfate-modified titanium-bearing blast furnace slag,STBBFS)催化剂.用X射线衍射、扫描电子显微镜和紫外-可见漫反射分析对硫酸盐修饰的含钛高炉渣催化剂进行了表征,确定其具有钙钛矿型;粉体的颗粒形态均为不规则形状,平均粒径为1.5μm左右;在紫外区域具有很强的光吸收能力.由六价铬的还原率来评价STBBFS催化剂的光催化活性,结果表明:与市售TiO2相比,钙钛矿型的STBBFS催化剂具有较高的光催化活性,500 W中压汞灯照射4 h,可将质量浓度为20 mg/L...     

TiO_2/Fe_3O_4/AC复合光催化剂的制备及其光催化活性研究

以粉末活性炭(AC)为载体,用共沉淀法制得Fe3O4/AC,再以钛酸四正丁酯为原料,采用溶胶-凝胶法制备了TiO2/Fe3O4/AC复合光催化剂(简称复合光催化剂).运用FT-IR、XRD、DRS、VSM测试方法对复合光催化剂进行表征,结果表明,该复合光催化剂包含有Fe3O4和TiO2成分.在紫外光照射下对偶氮砷染料的脱色反应表明,在照射时间为60min、催化剂投加量为0.1g、偶氮染料pH=2、初始浓度为10mg*L-1的最佳条件下,该复合光催化剂对偶氮染料的脱色率可达99%.     

Preparation, characterization and photocatalytic activity of N-doped TiO2 nanocrystals

N-doped TiO₂ nanocrystals were prepared using titanium alkoxide as precipitant with different proportional materials. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-vis diffuse reflectance spectra. It is confirmed experimentally that the photocatalytic activity of N-doped TiO₂ is much higher than that of Degussa P25, when used for the degradation of crystal violet. The degradation kinetics follows an apparent first-order reaction, which is consistent with a generally observed Langmuir-Hinshelwood mechanism. The doping of TiO₂ with nitrogen significantly increases the absorption in the region of visible light. The energy of the band gap of N-doped TiO₂ is 2.92 eV. The better performance of N-doped TiO₂ can be explained by the fact that it is also excited with longer-wavelength light.     

pH值对β-MnO2颗粒光催化去除银离子的影响

The presence of silver ions (Ag(I)) in wastewater has a detrimental effect on living organisms. Removal of soluble silver, especially at low concentrations, is challenging. This paper presents the use of β-MnO₂ particles as a photocatalyst to remove Ag(I) ions selectively from aqueous solution at various pH levels. Inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), field emission electron microscope (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron microscopy (XPS) were employed to determine the removal efficiency and to characterize the deposition of silver onto the surface of β-MnO₂ particles. The optimum pH for the removal of Ag(I) ions was at pH 4 with 99% removal efficiency under 1 h of visible light irradiation. This phenomenon can be attributed to the electrostatic attraction between β-MnO₂ particles and Ag(I) ions as well as the suppression of electron–hole recombination in the presence of H+ ions.     

石墨烯杂化钛酸管复合光催化剂的制备与表征

以化学法还原的石墨烯和纳米TiO2为原料,采用水热法制备出一系列具有良好可见光活性的石墨烯 钛酸管复合光催化剂,并研究石墨烯含量和水热温度对其光催化性能的影响.结果表明：当石墨烯质量分数为5%时,复合光催化剂的催化活性最佳;采用较低水热温度制备出的复合光催化剂具有更大的比表面积和更优异的催化性能,其比表面积为一般石墨烯 TiO2复合光催化剂的10倍;在可见光照射条件下,其降解罗丹明 B的速率常数可达8.76×10-2 min-1,远高于文献报道的TiO2类光催化剂降解的速率常数;其可见光活性来源于石墨烯的敏化作用.     

可见光响应复合高效光催化剂的制备及应用

采用溶胶-凝胶法将过渡金属离子Fe和稀土离子Sm共掺杂改性纳米TiO2,首次将其负载在具有大比面积、微孔结构丰富的活性炭纤维载体上,制备出新型复合高效光催化剂。以甲基橙模拟染料废水为降解目标,考察催化剂的光催化活性。通过XRD、SEM、BET等手段表征其性质。结果表明:共掺杂改性复合光催化剂的光催化活性要明显优于空白炭纤维、纯二氧化钛负载活性炭纤维和单掺杂改性复合光催化剂的光催化活性,当煅烧温度500℃、n(Fe)∶n(Sm)∶n(Ti)为0.05∶0.1∶1、TiO2在活性炭纤维上的负载量为45%时,光催化效果最好;将光催化剂重复利用7次后,再次降解高质量浓度甲基橙溶液,降解率仍然超过95%;新型复合光催化剂对工业RO浓缩水中COD去除率可达37.12%。     

A facile way to prepare visible light driven tin oxide based photoanode and its photoelectrochemical water splitting properties

Visible light driven tin oxide based photoelectrodes were obtained using SnCl2·2H2O EtOH solution on FTO by dipping and with further heat treatment in air.Photoelectrochemical measurement with three electrodes configuration under visible light irradiation(λ>420 nm) revealed that this as-prepared photoelectrode showed typical n-type photocurrent effect and the onset potential is negative than that of H+/H2.XRD,UV-Vis spectrum and control experimental results revealed that the visible light driven mechanism for the tin oxide based photoanode maybe ascribed to Sn4+/Sn2+ transformation and the surface oxygen deficiency.     

钙钛矿型氧化物光催化剂的制备及表征方法研究

光催化氧化技术是近年来国内外的一个热点研究领域,具有良好的应用前景.钙钛矿型氧化物由于其结构的稳定性和特殊的物化性能,日益成为光催化材料研究领域的重要课题.文中详细评述了钙钛矿型光催化剂的常用表征技术(XRD,XPS,TEM,UV-Vis DRS,BET等)和制备方法,重点对其中的传统高温固相法、溶胶-凝胶法以及水热法...     

响应曲面法优化硅藻土/TiO2制备及深度处理氨氮废水

为深度降解废水中的氨氮,以纳米TiO2和硅藻土为原料,利用化学沉淀法制备硅藻土负载TiO2纳米材料.在单因素设计和试验基础上,采用Box-Behnken响应曲面法,以氨氮(NH3-N)去除率为响应值建立数学模型,分析影响催化剂降解氨氮废水的多种因素.模型优化结果显示:在焙烧温度500℃,焙烧时间3h和负载量5g条件下,制备得到的负载催化剂具有最佳的去除效果,氨氮去除率为73.11%.验证试验进一步验证了建立的响应曲面在负载催化剂制备工艺优化中的有效性.     

光催化混凝土的研究与发展

文章介绍了新型绿色材料光催化混凝土的光催化原理、制备及净化性能测试方法，扼要说明了光催化混凝土存在的问题。