二噁英会降低人类的免疫力,影响人体和神经发育;氮氧化物则会对人体的各项脏器和血液组织有严重危害,还会破坏臭氧层,加速酸雨的形成.商业钒钛催化剂既能脱除氮氧化物又能催化分解二噁英(邻二氯苯作为模拟物),二噁英活性温度区为200~300...二噁英会降低人类的免疫力,影响人体和神经发育;氮氧化物则会对人体的各项脏器和血液组织有严重危害,还会破坏臭氧层,加速酸雨的形成.商业钒钛催化剂既能脱除氮氧化物又能催化分解二噁英(邻二氯苯作为模拟物),二噁英活性温度区为200~300℃,而脱硝活性温度为300~400℃.研究了VOx/TiO2、MnOx/TiO2以及VOx-MnOx/TiO2等催化剂在200~300℃脱硝、脱除二噁英的情况.结果表明,在VOx/TiO2催化剂中掺入MnOx促进脱硝活性温度区间由300~400℃往200~300℃偏移,当MnOx和VOx摩尔比为3∶1时,催化剂在250℃脱硝和脱除二噁英的效果最好,催化NO和邻二氯苯效率分别为92.0%和89.0%.原位红外漫反射光谱研究表明,1V3M/T催化剂表面的脱硝反应在250℃遵循L-H机理,—NH2、Nx Hy Oz、单齿亚硝酸盐和二齿硝酸盐是主要的反应中间体.展开更多
Pd-MnO2/TiO2 nanotube arrays（NTAs） photo-electrodes were successfully fabricated via anodization and electro deposition subsequently; the obtained Pd-MnO2/TiO2 NTAs photo electrodes were analyzed by scanning electro...Pd-MnO2/TiO2 nanotube arrays（NTAs） photo-electrodes were successfully fabricated via anodization and electro deposition subsequently; the obtained Pd-MnO2/TiO2 NTAs photo electrodes were analyzed by scanning electron microscopy（SEM）, X-ray diffraction（XRD） and characterized accordingly. Moreover, the light harvesting and absorption properties were investigated via ultraviolet–visible diffuse reflectance spectrum（DRS）; photo degradation efficiency was investigated via analyzing the photo catalytic degradation of Rhodamine B under visible illumination（xenon light）. The performed analyses illustrated that Pd-MnO2 codoped particles were successfully deposited onto the surface of the TiO2 nanotube arrays;DRS results showed significant improvement in visible light absorption which was between400 and 700 nm. Finally, the photo catalytic degradation efficiency results of the designated organic pollutant（Rhodamine B） illustrated a superior photocatalytic（PC） efficiency of approximately 95% compared to the bare TiO2 NTAs, which only exhibited a photo catalytic degradation efficiency of approximately 61%, thus it indicated the significant enhancement of the light absorption properties of fabricated photo electrodes and their yield of UOH radicals.展开更多
TiCl4 and MnSO4· H2O as raw materials are hydrolyzed stiochiometrically, following the intermediate of oxide hydrating reacts at 150°C, 0.5 MPa in high-pressure reactor, after filtering, washing and drying, ...TiCl4 and MnSO4· H2O as raw materials are hydrolyzed stiochiometrically, following the intermediate of oxide hydrating reacts at 150°C, 0.5 MPa in high-pressure reactor, after filtering, washing and drying, nanometric TiO2-MnO2 (Ti1-X Mn X O2) is prepared. The effects of the reaction temperature and time on nanometric TiO2-MnO2 are also discussed. XRD shows that the product is TiO2-MnO2 with amorphous phase. After being sintered at above 780 °C, it transfers into Ti1-X Mn X O2 with a rutile structure. TEM shows that TiO2-MnO2 is the spherical particle. And the average diameter of the particles is 20 nm. The optical absorbance was determined by UV-265 spectrophotometer after dispersing the sample in the mixture of water and glycerol with the ratio of 1 : 1 equably. It is found that the nano-material possesses the advantages of both nano-TiO2 and nano-MnO2, and it has strong absorption in the UV and visible region. Photodegradation of dyes in an aqueous solution is investigated using nanometricTiO2-MnO2 as a photocatalyst. The results show that after 60 min illumination, the decolorization rate of the acidic red B and acidic black 234 dye can be as high as 100%.展开更多
文摘二噁英会降低人类的免疫力,影响人体和神经发育;氮氧化物则会对人体的各项脏器和血液组织有严重危害,还会破坏臭氧层,加速酸雨的形成.商业钒钛催化剂既能脱除氮氧化物又能催化分解二噁英(邻二氯苯作为模拟物),二噁英活性温度区为200~300℃,而脱硝活性温度为300~400℃.研究了VOx/TiO2、MnOx/TiO2以及VOx-MnOx/TiO2等催化剂在200~300℃脱硝、脱除二噁英的情况.结果表明,在VOx/TiO2催化剂中掺入MnOx促进脱硝活性温度区间由300~400℃往200~300℃偏移,当MnOx和VOx摩尔比为3∶1时,催化剂在250℃脱硝和脱除二噁英的效果最好,催化NO和邻二氯苯效率分别为92.0%和89.0%.原位红外漫反射光谱研究表明,1V3M/T催化剂表面的脱硝反应在250℃遵循L-H机理,—NH2、Nx Hy Oz、单齿亚硝酸盐和二齿硝酸盐是主要的反应中间体.
基金supported by the National Natural Science Foundation of China (No. 51178138)the National Creative Research Groups of China (No. 51121062)the State Key Laboratory of Urban Water Resources and Environment (No. 2010DX03)
文摘Pd-MnO2/TiO2 nanotube arrays（NTAs） photo-electrodes were successfully fabricated via anodization and electro deposition subsequently; the obtained Pd-MnO2/TiO2 NTAs photo electrodes were analyzed by scanning electron microscopy（SEM）, X-ray diffraction（XRD） and characterized accordingly. Moreover, the light harvesting and absorption properties were investigated via ultraviolet–visible diffuse reflectance spectrum（DRS）; photo degradation efficiency was investigated via analyzing the photo catalytic degradation of Rhodamine B under visible illumination（xenon light）. The performed analyses illustrated that Pd-MnO2 codoped particles were successfully deposited onto the surface of the TiO2 nanotube arrays;DRS results showed significant improvement in visible light absorption which was between400 and 700 nm. Finally, the photo catalytic degradation efficiency results of the designated organic pollutant（Rhodamine B） illustrated a superior photocatalytic（PC） efficiency of approximately 95% compared to the bare TiO2 NTAs, which only exhibited a photo catalytic degradation efficiency of approximately 61%, thus it indicated the significant enhancement of the light absorption properties of fabricated photo electrodes and their yield of UOH radicals.
基金This work was supported by the Natural Science Foundation of Hebei Province,China(Grant No.202104).
文摘TiCl4 and MnSO4· H2O as raw materials are hydrolyzed stiochiometrically, following the intermediate of oxide hydrating reacts at 150°C, 0.5 MPa in high-pressure reactor, after filtering, washing and drying, nanometric TiO2-MnO2 (Ti1-X Mn X O2) is prepared. The effects of the reaction temperature and time on nanometric TiO2-MnO2 are also discussed. XRD shows that the product is TiO2-MnO2 with amorphous phase. After being sintered at above 780 °C, it transfers into Ti1-X Mn X O2 with a rutile structure. TEM shows that TiO2-MnO2 is the spherical particle. And the average diameter of the particles is 20 nm. The optical absorbance was determined by UV-265 spectrophotometer after dispersing the sample in the mixture of water and glycerol with the ratio of 1 : 1 equably. It is found that the nano-material possesses the advantages of both nano-TiO2 and nano-MnO2, and it has strong absorption in the UV and visible region. Photodegradation of dyes in an aqueous solution is investigated using nanometricTiO2-MnO2 as a photocatalyst. The results show that after 60 min illumination, the decolorization rate of the acidic red B and acidic black 234 dye can be as high as 100%.
