采用TiO2光催化剂对河水中污染物进行光催化降解

用光催化剂TiO2对西清河废水进行了废水处理研究.实验结果表明,随着催化剂用量的增加,COD、色度的去除率逐渐增大, 但当其用量超过0.5g时,COD、色度的去除率增加缓慢,超过0.6g时开始下降;当pH<6.5时,随着pH值降低,当pH>6.5时,随着pH值升高,COD、色度去除率均降低;随着光照时间延长,COD、色度去除率逐渐升高,但当光照时间超过 10h 后, COD、色度去除率升高幅度非常缓慢.当催化剂用量为0.6g、 pH =6.5、光照12 h时,西清河废水的COD、色度去除率分别达到75.0%、78.5%.     

Recent advances in graphene based photoresponsive materials

Recent scientific interests reveal that graphene, with its flexibility, chemical stability, thermal conductivity,unique electronic band structure and optical transmittance, has emerged as the novel supporting material for nanocomposites for various applications. Research interests have flourished regarding decoration of conventional materials with modified graphene for achieving better optical properties. More concern is given for achieving improved photoresponse with graphene as the supporting material. The giant electron mobility and transparency of graphene enables the photo-induced electron transfer in the hybrid material, resulting in enhanced behaviour. Graphene oxide is able to effectively convert near infrared energy into heat, potentially acting as a photo-thermal switch. They act as potential candidates for photo-catalysts, sensors, photo-current switching,photo-detectors and other optical applications. In this review, we summarized the recent developments on fabrication and properties of graphene based photoresponsive materials.     

纳米钨酸锌的制备及其光催化性质的研究

旨在探索利用水热法合成钨酸锌材料的纳米结构,并对其所合成的材料的结构和形貌进行表征,测试了合成材料的光催化性质,以硝酸锌和钨酸钠作起始物,用PVP和SDBS作为修饰剂利用水热法合成不同形貌的纳米钨酸锌。利用X射线粉末衍射（XRD）、透射电子显微镜（TEM）等对产物进行表征。测试了合成钨酸锌纳米材料的紫外光催化性质,表明合成的钨酸锌具有较高的紫外光催化活性,说明钨酸锌具有潜在的应用价值。     

Photocatalytic Reduction of Carbon Dioxide with Modify Pd, Ru on TiO2 Surface

Photocatalytic reduction of CO2 to organic compounds was reduction in semiconductor suspension system under simulated solar in laboratory. TiO2 load catalysts were prepared in different ways, and they were used in photocatalytic reduction of CO2 . Experimental results show that the photocatalytic activity can be improve by dressing Pd, Ru on TiO2 Surface and is obvious different when catalysts were prepared in different ways. The photocatalytic mechanism of dressing Pd on TiO2 Surface; dressing Pd and Ru on TiO2 Surface were also discussed in this paper.     

乙醇水溶液可见光催化脱氢的研究

考察了光催化剂浓度、粒径、反应温度、乙醇浓度和高温热处理对悬浮Pd/CdS粉末光催化剂的乙醇水溶液可见光催化脱氢活性的影响,得出2.5m gml~(-1)为最佳催化剂浓度,活性达300ml/h·l;温度在305～365K内,反应的表观活化能为36.6kJmol~(-1);在乙醇浓度低于50％时,脱氢反应对乙醇是一级反应;实验证明高温热处理使Pd颗粒向内表面扩散,且强化Pd移去CdS表面的自由电子,两者均提高脱氢活性;得到选择性高于70％的主要氧化产物乙醛;提出了可能的反应机理。     

高效能光触媒的研究进展

根据国内外文献资料对提高光触媒效能的几种主要技术进行了综述,结合工作实践,对高效能光触媒未来的发展方向进行了展望.     

光催化氧化-生物法处理有机磷农药废水

探讨了“磁性颗粒负载型TiO2”用于光催化氧化-生物工艺,处理有机磷农药废水的可行性。试验结果表明,难降解废水经80min光催化氧化后,在生物段的COD去除率可达85％以上;在光催化预处理阶段生成的中间产物(对硝基苯酚和磷酸三乙酯)对后续生物处理会产生特别严重的影响,因此适当的光催化预处理程度是保证该工艺能够经济、高效运行的关键。     

Influence of operational parameters on the photocatalytic performance of DE-NOx process Via MIL-101(Fe)

Metal organic framework(MOF)has been paid great attention as a potential candidate for various applications in the field of energy and environment,particularly in air purification.Among various MOFs,MIL-101(Fe) represents an interesting material possessing many advantages,including the ease of fabrication,high porosity,high specific surface area with open metal sites,making it a promising material in the field of harmful gas treatment.Taking these advantages,MIL-101(Fe) was synthesized by facile microwave-solvothermal method and applied as a photocatalyst for the degradation of NO_x.The de-NO_x efficiency of the synthesized powder was evaluated with respect to various operating parameters including substrates,sample doses,light spectrum and light intensity,initial NO concentration,and relative humidity.The results have shown that the efficiency of NO_x photocatalytic degradation reaches to 77%under solar irradiation via 0.1 g of MIL-101(Fe) with optimum condition of reaction,(alumina substrate,350 ppb of initial NO concentration,40–50%of relative humidity).Then this work provides the optimum condition for the efficient photocatalytic degradation of NO_x.     

Gd–La codoped TiO_2 nanoparticles as solar photocatalysts

Gd–La codoped Ti O2 nanoparticles with diameter of 10 nm were successfully synthesized via a sol–gel method. The photocatalytic activity of the Gd–La codoped Ti O2 nanoparticles evaluated by photodegrading methyl orange was significantly enhanced compared to that of undoped or Gd or La mono-doped Ti O2. Ti4+tmay substitute for La3+tand Gd3+tin the lattices of rare earth oxides to create abundant oxygen vacancies and surface defects for electron trapping and dye adsorption, accelerating the separation of photogenerated electron–hole pairs and methyl orange photodegradation. It is believed that the formation of an excitation energy level below the conduction band of Ti O2 from the binding of electrons and oxygen vacancies decreases the excitation energy of Gd–La codoped Ti O2, resulting in versatile solar photocatalysts. The results suggest that Gd–La codoped Ti O2 nanoparticles are promising for future solar photocatalysts.     

Photocatalytic degradation of benzene in gas phase by nanostructured BiPO4 catalysts

A rod-shaped BiPO4 photocatalyst was prepared by a simple hydrothermal method for light-induced catalytic degradation of stable aromatic compounds such as benzene in gas phase under ambient conditions. The samples were subjected to various technical characterizations including X-ray diffraction (XRD), transmission electron microscopy (TEM), UV/vis and FTIR spectrum, to determine the crystal structure, morphology, and optical properties of the as-prepared photocatalysts. Results indicate that BiPO4 exhibits much higher photocatalytic activity and stability under UV light irradiation than that of commercial TiO2 (Degussa P25) in the degradation of benzene to CO2. The active radical species involved in the degradation reactions over BiPO4 photocatalyst have been investigated by the spin-trapping electron paramagnetic resonance (EPR) spectra and a photoluminescence technique. Theoretical calculations reveal that BiPO4 contains highly-dispersive conduction bands, enabling high mobility of the photo-generated carries and therefore leading to fast charge transfer and separation.