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1.
Akira Yamamoto Kentaro Teramura Saburo Hosokawa Tsunehiro Tanaka 《Science and Technology of Advanced Materials》2015,16(2)
The effect of SO2 gas was investigated on the activity of the photo-assisted selective catalytic reduction of nitrogen monoxide (NO) with ammonia (NH3) over a TiO2 photocatalyst in the presence of excess oxygen (photo-SCR). The introduction of SO2 (300 ppm) greatly decreased the activity of the photo-SCR at 373 K. The increment of the reaction temperature enhanced the resistance to SO2 gas, and at 553 K the conversion of NO was stable for at least 300 min of the reaction. X-ray diffraction, FTIR spectroscopy, thermogravimetry and differential thermal analysis, x-ray photoelectron spectroscopy (XPS), elemental analysis and N2 adsorption measurement revealed that the ammonium sulfate species were generated after the reaction. There was a strong negative correlation between the deposition amount of the ammonium sulfate species and the specific surface area. Based on the above relationship, we concluded that the deposition of the ammonium sulfate species decreased the specific surface area by plugging the pore structure of the catalyst, and the decrease of the specific surface area resulted in the deactivation of the catalyst. 相似文献
2.
Harshavardhan Mohan Jeong-Muk Lim Se-Won Lee Min Cho Yool-Jin Park Kamala-Kannan Seralathan Byung-Taek Oh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2020,95(1):297-307
The cover image is based on the Research Article V2O5/RGO/Pt nanocomposite on oxytetracycline degradation and pharmaceutical effluent detoxification by Mohan, H et al., DOI: 10.1002/jctb.6238 .
3.
Titanium Dioxide, TiO2, is a photocatalyst with a unique characteristic. A surface coated with TiO2 exhibits an extremely high affinity for water when exposed to UV light and the contact angle decreases nearly to zero. Inversely, the contact angle increases when the surface is shielded from UV. This superhydrophilic nature gives a self-cleaning effect to the coated surface and has already been applied to some construction materials, car coatings and so on. We applied this property to the enhancement of boiling heat transfer. An experiment involving the pool boiling of pure water has been performed to make clear the effect of high wettability on heat transfer characteristics. The heat transfer surface is a vertical copper cylinder of 17 mm in diameter and the measurement has been done at saturated temperature and in a steady state. Both TiO2-coated and non-coated surfaces were used for comparison. In the case of the TiO2-coated surface, it is exposed to UV light for a few hours before experiment and it is found that the maximum heat flux (CHF) is about two times larger than that of the uncoated surface. The temperature at minimum heat flux (MHF) for the superhydrophilic surface is higher by 100 K than that for the normal one. The superhydrophilic surface can be an ideal heat transfer surface. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
4.
采用非平衡等离子体与光催化剂相结合,对苯的降解进行了实验研究。考察了以不同吸附能力的玻璃球和γ-Al2O3为载体对苯降解率、碳平衡、CO2选择性、NOx及O3生成量的影响;研究了以γ-Al2O3为载体时,水蒸气含量对苯的降解率、碳平衡、CO2选择性、NOx及O3生成量的影响。实验结果表明,以具有吸附性的γ-Al2O3为载体可提高苯的降解率;当能量密度为618J/L时,苯的降解率可达98%;同时可降低O3的生成量,但NOx生成量增加;以γ-Al2O3为载体时,随水蒸气含量的增加,苯的降解率降低,特别是在低能量密度时,水蒸气对苯降解率的影响更为显著,但水蒸气的加入可抑制O3的生成,同时可提高碳平衡值。 相似文献
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6.
以Fe(Ⅲ)离子交换改性膨润土,制得一种多相Fenton催化剂;以4-氯苯酚为模型污染物,研究不同反应条件的影响。结果表明,复合催化剂主要含SiO2及α-Fe2O3两种晶型,Fe是以高催化活性的α-Fe2O3形式存在。复合催化剂在H2O2及紫外光的协同作用下,经60 min反应后对4-氯苯酚的降解率约100%,TOC去除率约70%,且其循环使用性能较好。在实际操作过程中,控制溶液体系的pH值为6以及H2O2与4-氯苯酚浓度比约15较为适宜;在4-氯苯酚的降解过程中,C—Cl键持续断裂,Cl-被释放出来,降解过程生成了一些不含氯的中间产物。 相似文献
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8.
以醋酸锌和氯氧化锆为原料,采用化学沉淀法制备了纳米氧化锆/氧化锌光催化剂。在中性条件下研究了催化剂煅烧温度,锆复合量,催化剂用量,染料初始质量浓度,过氧化氢质量浓度,各种阴、阳离子等条件对酸性红B脱色反应的影响。结果表明,该催化剂最佳制备条件为煅烧温度350℃,锆复合量2.5%(物质的量分数)。催化剂最佳用量0.9g/L。提高染料初始质量浓度会降低反应脱色率。适量过氧化氢可提高反应脱色率,当其质量浓度超过300mg/L会起负作用。NO3^-对反应影响不大;Fe^3+和Ag^+对反应起促进作用;SO4^2-,Cl^-,NO2^-等阴离子和Fe^2+,Mn^2+等阳离子对反应起抑制作用。 相似文献
9.
非金属掺杂的第二代二氧化钛光催化剂研究进展 总被引:13,自引:1,他引:13
寻求廉价、环境友好并具有可见光光催化活性的第二代光催化剂将是光催化发展进一步走向实用化的关键。氮掺杂的TIO2是新发现的具有可见光光催化活性的复合光催化剂,非金属掺杂可以使复合物的复合禁带宽度小于TIO2的禁带宽度,从而使TIO2的吸收边向可见光移动。对TIO2的氮、碳、硫、卤素掺杂国内外研究现状进行了系统评述,分析了提高TIO2可见光活性的原因,指出非金属元素特别是氮元素的阴离子掺杂是在不降低紫外光催化活性的基础上实现可见光响应的较好方法。 相似文献
10.
The coupled photocatalyst WO3/TiO2 is prepared by ball milling by doping WO3 into TiO2 and using H2O solution as disperser. The coupled photocatalyst WO3/TiO2 is characterized by UV–VIS diffuse reflection spectrum, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Transmission electron microscopy (TEM). The results show that the optimum percentage of WO3 doped is 3% and that the photocatalytic activity of the coupled WO3/TiO2 photocatalyst is much higher than that of TiO2 and WO3–TiO2 with no ball milling. Compared with TiO2, the photoexcited wavelength range of the WO3/TiO2 photocatalyst red-shifts about 50 nm, and the light absorption intensity is also improved. The crystal phase of TiO2 is not changed and new crystal phases are not found during the process of ball milling. WO3 and TiO2 coupled highly, forming the WO3/TiO2 photocatalyst. The increased photocatalytic activity of the coupled photocatalyst may be attributed to the enhance charge separation efficiency and the extend wavelength range of photoexcitation. 相似文献