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1.
TiO2 films were prepared by sol-gel method. In order to improve the utilization of light, the technologies of implantation of
transition metal ions (V+ and Cr+) and electron beam irradiation to deposit noble metal particles (Ag and Pt) were used. A red shift was found in the spectrum
of modified TiO2 films. The photocatalytic experiments showed that the photocatalytic ability under visible light irradiation could be improved
dramatically by both the implantation of transition metal and the electron beam irradiation.
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Translated from Chinese Journal of Catalysis, 2007, 28(1): 39–44 [译自: 催化学报] 相似文献
2.
Masato Takeuchi Masaya Matsuoka Masakazu Anpo 《Research on Chemical Intermediates》2012,38(6):1261-1277
The successful application of ion engineering techniques for the development of TiO2 photocatalysts operating under visible and/or solar light irradiations has been summarized in this review article. First,
we have physically doped various transition metal ions within a TiO2 lattice on an atomic level by using an advanced metal ion implantation method. The metal ion implanted TiO2 could efficiently work as a photocatalyst under visible light irradiation. Some field tests under solar light irradiation
clearly revealed that the Cr or V ions implanted TiO2 samples showed 2–3 times higher photocatalytic reactivity than the un-implanted TiO2. Second, we have developed the visible light responsive TiO2 thin film photocatalyst by a single process using an RF-magnetron sputtering (RF-MS) deposition method. The vis-type TiO2 thin films showed high photocatalytic reactivity for various reactions such as reduction of NOx, degradation of organic compounds,
and splitting of H2O under visible and/or solar light irradiations. 相似文献
3.
Masato Takeuchi Shiro Sakai Masaya Matsuoka Masakazu Anpo 《Research on Chemical Intermediates》2009,35(8-9):973-983
TiO2 thin film photocatalysts which could induce photoreactions under visible light irradiation were successfully developed in a single process by applying an ion engineering technique, i.e., the radio frequency (RF) magnetron sputtering deposition method. The TiO2 thin films prepared at temperatures greater than 773 K showed the efficient absorption of visible light; on the other hand, the TiO2 thin films prepared at around 573 K were highly transparent. This clearly means that the optical properties of TiO2 thin films, which absorb not only UV but also visible light, can be controlled by the preparation temperatures of the RF magnetron sputtering deposition method. These visible light responsive TiO2 thin films were found to exhibit effective photocatalytic reactivity under visible light irradiation (λ > 450 nm) at 275 K for the reductive decomposition of NO into N2 and N2O. From various characterizations, the orderly aligned columnar TiO2 crystals could be observed only for the visible light responsive TiO2 thin films. This unique structural factor is expected to modify the electronic properties of a TiO2 semiconductor, enabling the efficient absorption of visible light. 相似文献
4.
Masato Takeuchi Kouichirou Tsujimaru Kenji Sakamoto Masaya Matsuoka Hiromi Yamashita Masakazu Anpo 《Research on Chemical Intermediates》2003,29(6):619-629
Platinum-loaded titanium oxide thin-film photocatalysts were prepared by using an ionized cluster beam (ICB) deposition method and a RF magnetron sputtering (RF-MS) deposition method as dry processes. From the results of the photocatalytic oxidation of acetaldehyde with O2 under UV light irradiation, small amounts of Pt loading (less than 10 nm film thickness) were found to dramatically enhance the photocatalytic reactivity. However, when TiO2 thin films were loaded with relatively larger amounts of Pt (more than 30 nm as the film thickness), the photocatalytic reactivity became lower than for the pure TiO2 thin films. Moreover, investigations of the ratio of Pt loaded onto the surface of the thin film catalysts by XPS measurements revealed that the small amounts of Pt loaded exist as very small clusters working to efficiently enhance the charge separation, whereas, large amounts of Pt covers the entire surface of the TiO2 thin films, resulting in a decrease of the photocatalytic reactivity. 相似文献
5.
Nitrogen and cerium codoped TiO2 photocatalysts were prepared by a modified sol-gel process with doping precursors of cerium nitrate and urea, and characterized by X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray photoelectron spectra (XPS) and ultraviolet-visible light diffuse reflectance spectra (UV-vis DRS). Results indicate that anatase TiO2 is the dominant crystalline type in as-prepared samples, and CeO2 crystallites appear as the doping ratio of Ce/Ti reaches to 3.0 at%. The TiO2 starts to transform from amorphous phase to anatase at 987.1 K during calcination, according to the TG-DSC curves. The XPS show that three major metal ions of Ce3+, Ce4+, Ti4+ and one minor metal ion of Ti3+ coexist on the surface. The codoped TiO2 exhibits significant absorption within the range of 400-500 nm compared to the non-doped and only nitrogen-doped TiO2. The enhanced photocatalytic activity of the codoped TiO2 is demonstrated through degradation of methyl orange under visible light irradiation. 相似文献
6.
M. Kitano M. Matsuoka T. Hosoda M. Ueshima M. Anpo 《Research on Chemical Intermediates》2008,34(5-7):577-585
The effects of HF treatment on the activity of TiO2 thin films for the photocatalytic water splitting reaction have been investigated. TiO2 thin films treated with HF solution (HF-TiO2) were found to exhibit a remarkable enhancement of the photocatalytic activity for H2 evolution from a methanol aqueous solution, as well as efficient photoelectrochemical performance under UV light irradiation as compared with the untreated TiO2. Moreover, Pt-loaded HF-TiO2 thin films were found to act as efficient and stable photocatalysts for the decomposition of water under UV light irradiation. The mechanistic insights obtained in the present study will be useful in the design of highly efficient photocatalysts for the decomposition of water. 相似文献
7.
Novel visible-light-activated photocatalytic Ag/InVO4-TiO2 thin films were developed in this paper through a sol-gel method from the TiO2 sol containing Ag and InVO4. The photocatalytic activities of Ag/InVO4-TiO2 thin films were investigated based on the oxidation decomposition of methyl orange in aqueous solution. The Ag/InVO4-TiO2 thin films were characterized by X-Ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron
spectroscopy (XPS) and UV-vis absorption spectroscopy (UV-vis). The results revealed that the Ag/InVO4-TiO2 thin films extended the light absorption spectrum toward the visible region; the Ag and InVO4 co-doped thin films significantly enhanced the methyl orange photodegradation under visible light irradiation. It has been
confirmed that the Ag/InVO4-TiO2 thin films could be excited by visible light (E < 3.2 eV). The significant enhancement in the Ag/InVO4-TiO2 photo activity under visible light irradiation can be ascribed to the simultaneous effects of doped noble metal Ag by acting
as electron traps and InVO4 as narrow band gap sensitizer. 相似文献
8.
Sreenu Kurra Perala Venkataswamy Gundeboina Ravi Chandhiri Sudhakar Reddy Boggu Jaganmohan Reddy Muga Vithal 《无机化学与普通化学杂志》2019,645(5):529-536
Perovskite type oxides, sodium bismuth titanate (Na0.5Bi0.5TiO3), and Ag+, Cu2+, and Sn2+ doped Na0.5Bi0.5TiO3 were prepared by pechini and ion exchange methods, respectively. Photocatalytic activities of these catalysts were tested by decomposition of methylene blue (MB) under visible light irradiation. Results showed that the photocatalytic activity of metal ion doped Na0.5Bi0.5TiO3 was higher than undoped Na0.5Bi0.5TiO3. Relatively high photocatalytic performance of Ag+‐doped Na0.5Bi0.5TiO3 is mainly ascribed to the efficient separation of electron‐hole (e–, h+) pairs, lower bandgap energy and the creation of active hydroxyl radicals ( ? OH). Further, the Ag+‐doped Na0.5Bi0.5TiO3 catalyst showed good reusability up to four cycles. A possible mechanism for the enhanced photocatalytic performance was proposed. The synthesized photocatalysts were characterized by XRD, SEM, EDS, XPS, FT‐IR, and UV/Vis DRS techniques. 相似文献
9.
Masakazu Anpo Yuichi Ichihashi Masato Takeuchi Hiromi Yamashita 《Research on Chemical Intermediates》1998,24(2):143-149
The metal ion-implantation of titanium oxide with various transition metal ions was carried out by applying by high voltage
acceleration. The subsequent calcination of the implanted TiO2 in oxygen at around 723 K resulted in a large shift in the absorption spectra of the TiO2 toward visible light regions, its extent being dependent on the amount and the kind of metal ions implanted. Such metal ion-implanted
titanium oxide catalysts were active in carrying out various photocatalytic reactions such as the decomposition of NO into
N2, O2 and N2O at 275 K under irradiation with visible light longer than 450 nm. The application of this advanced, high energy metal ion-implantation
method enables the novel design of titanium oxide photocatalysts which can absorb and initiate vital reactions under visible
light and will contribute to the development of catalytic systems utilizing solar energy. 相似文献
10.
Nitrogen-doped and oxygen-deficient TiO2 microspheres (NT) with large specific surface were prepared by a solvothermal method and following with electron beam (EB) irradiation under various doses (140–500 kGy). XPS results show that under the EB irradiation, nitrogen ions have been doped into the TiO2 lattice successfully, as well as part of Ti4+ on the surface of the samples changed to Ti3+. Photocatalytic performance was tested by decomposing Rhodamine B in the aqueous phase under visible light irradiation. The prepared materials under the EB irradiation at dose of 140 kGy (NT-140) exhibit the best visible light photocatalytic activity. It is attributed to the large specific surface (138.4 m2/g) and a synergistic effect between substitutional nitrogen dopants and oxygen defects in NT-140. The results obtained may provide a new sight for the application of EB-assisted preparation of nanomaterials. 相似文献
11.
12.
The InVO4 sol was obtained by a mild hydrothermal treatment (the precursor precipitation solution at 423 K, for 4 h). Novel visible-light
activated photocatalytic InVO4–TiO2 thin films were synthesized through a sol–gel dipping method from the composite sol, which was obtained by mixing the low
temperature InVO4 sol and TiO2 sol. The photocatalytic activities of the new InVO4–TiO2 thin films under visible light irradiation were investigated by the photocatalytic discoloration of methyl orange aqueous
solution. The thin films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM)
and UV–Vis absorption spectroscopy (UV–Vis). The results revealed that the InVO4 doped thin films enhanced the methyl orange degradation rate under visible light irradiation, 3.0 wt% InVO4–TiO2 thin films reaching 80.1% after irradiated for 15 h. 相似文献
13.
《化学:亚洲杂志》2017,12(8):882-889
Ag0.5La0.5TiO3 with an ABO3 perovskite structure was synthesized by a newly developed ion‐exchange method. Molten Ag2SO4 instead of traditional molten AgNO3 was used as Ag+ source in view of its high decomposition temperature (1052 °C), thereby guaranteeing the complete substitution of Ag+ for Na+ in Na0.5La0.5TiO3 with a stable ABO3 perovskite structure at a high ion‐exchange temperature (700 °C). Under full‐arc irradiation, the O2‐evolution activity of Ag0.5La0.5TiO3 was about 1.6 times that of Na0.5La0.5TiO3 due to the optimized electronic band structures and local lattice structures. On the one hand, the substitution of Ag+ for Na+ elevated the VBM and thus narrowed the band gap from 3.19 to 2.83 eV, thereby extending the light‐response range and, accordingly, enhancing the photoexcitation to generate more charge carriers. On the other hand, the substitution of Ag+ for Na+ induced a lattice distortion of the ABO3 perovskite structure, thereby promoting the separation and migration of charge carriers. Moreover, under visible‐light irradiation, Ag0.5La0.5TiO3 displayed notable O2 evolution whereas Na0.5La0.5TiO3 showed little O2 evolution, thus demonstrating that the substitution of Ag+ for Na+ enabled the use of visible light to evolve O2 photocatalytically. This work presents an effective route to explore novel Ag‐based photocatalysts. 相似文献
14.
Behzad Koozegar Kaleji Navid Hosseinabadi 《Journal of Sol-Gel Science and Technology》2014,69(2):412-417
In this work, Sn and Nb co-doped TiO2 were coated on glazed porcelain substrates via sol–gel dip coating method. Field emission-scanning electron microscopy, transmission electron microscopy, and UV–vis spectrophotometer were used to evaluate thickness and optical properties of the thin films. Surface chemical state of thin films was examined by atomic X-ray photoelectron spectroscopy. Water contact angle on the film surfaces was measured by a contact angle analyzer under solar light irradiation. The optical results indicated that Sn/Nb dopant in TiO2 thin film changed the absorption edge from ultraviolet to visible light and exhibited excellent photo-catalytic ability for degradation of methylene blue solution under solar irradiation. Wettability results indicated that Sn and Nb dopant ions had significant effect on the hydrophilicity property of thin films. 相似文献
15.
Zr离子掺杂TiO2可见光催化剂光催化活性的研究 总被引:3,自引:0,他引:3
本文采用溶胶-凝胶法制备了Zr离子掺杂TiO2光催化剂。光催化降解对氯苯酚实验表明,Zr离子掺杂浓度为10%时活性最高,其紫外光、可见光催化活性分别是纯TiO2的1.5倍和4倍。利用XRD、Raman、XPS、UV-Vis DRS、PL等技术对样品进行了表征,结果表明:Zr离子以取代式掺杂方式进入TiO2晶格,在TiO2导带下方形成掺杂能级,增强了可见光响应,促进了光生载流子的分离,此外Zr离子掺杂在催化剂表面引入大量表面缺陷,增加了表面羟基物种,从而使得Zr离子掺杂TiO2光催化剂的紫外、可见光催化活性显著提高。 相似文献
16.
用固相反应合成法合成了光催化剂Fe2BiTaO7,通过XRD、SEM、TEM、紫外-可见漫反射等表征方法对其组织结构及光催化性能进行了研究.结果表明Fe2BiTaO7为立方晶系烧绿石结构,空间群为Fd3m,禁带宽度为1.72eV.通过比较Fe2BiTaO7、P25TiO2、掺氮TiO2和Bi2InTaO7的可见光光催化降解罗丹明B,发现Fe2BiTaO7降解效果及催化活性均高于其它催化剂,并且Fe2BiTaO7降解罗丹明B效率是掺氮二氧化钛的1.5倍.Fe2BiTaO7降解罗丹明B的曲线符合一级动力学,一级动力学常数为0.02293 min-1.研究了罗丹明B可能的降解路径和Fe2BiTaO7在可见光下降解苯酚的效果.Fe2BiTaO7(可见光)光催化剂系统适用于纺织工业废水处理. 相似文献
17.
Medium energy,heavy and inert ion irradiation of metallic thin films: studies of surface nano‐structuring and metal burrowing
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Pravin Kumar Kedar Mal Sunil Kumar Indra Sulania 《Surface and interface analysis : SIA》2016,48(9):969-975
In context to the ion induced surface nanostructuring of metals and their burrowing in the substrates, we report the influence of Xe and Kr ion‐irradiation on Pt:Si and Ag:Si thin films of ~5‐nm thickness. For the irradiation of thin films, several ion energies (275 and 350 keV of Kr; 450 and 700 keV of Xe) were chosen to maintain a constant ratio of the nuclear energy loss to the electronic energy loss (Sn/Se) in Pt and Ag films (five in present studies). The ion‐fluence was varied from 1.0 × 1015 to 1.0 × 1017 ions/cm2. The irradiated films were characterized using Rutherford backscattering spectroscopy (RBS), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The AFM and SEM images show ion beam induced systematic surface nano‐structuring of thin films. The surface nano‐structures evolve with the ion fluence. The RBS spectra show fluence dependent burrowing of Pt and Ag in Si upon the irradiation of both ion beams. At highest fluence, the depth of metal burrowing in Si for all irradiation conditions remains almost constant confirming the synergistic effect of energy losses by the ion beams. The RBS analysis also shows quite large sputtering of thin films bombarded with ion beams. The sputtering yield varied from 54% to 62% by irradiating the thin films with Xe and Kr ions of chosen energies at highest ion fluence. In the paper, we present the experimental results and discuss the ion induced surface nano‐structuring of Pt and Ag and their burrowing in Si. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
18.
Titanium dioxide (TiO2), co-deposited with Fe and N, is first implanted with Fe by a metal plasma ion implantation (MPII) process and then annealed in N2 atmosphere at a temperature regime of 400-600 °C. First-principle calculations show that the (Fe, N) co-deposited TiO2 films produced additional band gap levels at the bottom of the conduction band (CB) and on the top of the valence band (VB). The (Fe, N) co-deposited TiO2 films were effective in both prohibiting electron-hole recombination and generating additional Fe-O and N-Ti-O impurity levels for the TiO2 band gap. The (Fe, N) co-deposited TiO2 has a narrower band gap of 1.97 eV than Fe-implanted TiO2 (3.14 eV) and N-doped TiO2 (2.16 eV). A significant reduction of TiO2 band gap energy from 3.22 to 1.97 eV was achieved, which resulted in the extension of photocatalytic activity of TiO2 from UV to Vis regime. The photocatalytic activity and removal rate were approximately two-fold higher than that of the Fe-implanted TiO2 under visible light irradiation. 相似文献
19.
《Surface and interface analysis : SIA》2018,50(7):705-712
We report the influence of 100 keV H+ ion beam irradiation on the surface morphology, crystalline structure, and transport properties of as‐deposited Al‐doped ZnO (Al:ZnO) thin films. The films were deposited on silicon (Si) substrate by using DC sputtering technique. The ion irradiation was carried out at various fluences ranging from 1.0 × 1012 to 3.0 × 1014 ions/cm2. The virgin and ion‐irradiated films were characterized by X‐ray diffraction, Raman spectroscopy, atomic force microscopy, and Hall probe measurements. Using X‐ray diffraction spectra, 5 points Williamson‐Hall plots were drawn to deduce the crystallite site and strain in Al:ZnO films. The analysis of the measurements shows that the films are almost radiation resistant in the structural deformation under chosen irradiation conditions. With beam irradiation, the transport properties of the films are also preserved (do not vary orders of magnitude). However, the surface roughness and the crystallite size, which are crucial parameters of the ZnO film as a gas sensor, are at variation with the ion fluence. As ion fluence increases, the root‐mean‐square surface roughness oscillates and the surface undergoes for smoothening with irradiation at chosen highest fluence. The crystallite size decreases initially, increases for intermediate fluences, and drops almost to the value of the pristine film at highest fluence. In the paper, these interesting experimental results are discussed in correlations with ion‐matter interactions especially energy losses by the ion beam in the material. 相似文献
20.
用固相反应合成法合成了光催化剂Fe2BiTaO7,通过XRD、SEM、TEM、紫外-可见漫反射等表征方法对其组织结构及光催化性能进行了研究。结果表明Fe2BiTaO7为立方晶系烧绿石结构,空间群为Fd3m,禁带宽度为1.72 e V。通过比较Fe2BiTaO7、P25TiO2、掺氮Ti O2和Bi2In Ta O7的可见光光催化降解罗丹明B,发现Fe2BiTaO7降解效果及催化活性均高于其它催化剂,并且Fe2BiTaO7降解罗丹明B效率是掺氮二氧化钛的1.5倍。Fe2BiTaO7降解罗丹明B的曲线符合一级动力学,一级动力学常数为0.022 93 min-1。研究了罗丹明B可能的降解路径和Fe2BiTaO7在可见光下降解苯酚的效果。Fe2BiTaO7(可见光)光催化剂系统适用于纺织工业废水处理。 相似文献