Lanthanum and boron co-doped BiVO4 with enhanced visible light photocatalytic activity for degradation of methyl orange

BiVO4 photocatalysts co-doped with La and B were prepared by sol-gel method using citric acid as chelate.The samples were characterized by X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),scanning electron microscopy(SEM),Brumauer-Emmett-Teller(BET),UV-Vis diffuse reflectance spectra(DRS) and the photocatalytic activity was investigated by photocatalytic degradation of methyl orange(MO).The results showed that boron and lanthanum ions incorporated into the lattice of BiVO4,and co-doping led to more surface oxygen vacancies,high specific surface areas,small crystallite size,narrow band gap and intense light absorbance in visible region.And the doped La(III) ions could help the separation of photogenerated electrons.Compared with BiVO4 and B-BiVO4,the photocatalytic activity of La-B co-doped BiVO4 was remarkably improved due to the synergistic effects of the co-doped ions.The degradation rate of MO in 60 min was 98.4% when La doping content was 0.05 mol.%,which was much higher than that of pure BiVO4(20%) and B-BiVO4(37%).     

A novel visible-light Nd-doped CdTe photocatalyst for degradation of Reactive Red 43：Synthesis,characterization, and photocatalytic properties

Novel high-efficiency visible-light-sensitive Nd-doped Cd Te nanoparticles were prepared with various doping concentrations of neodymium ion by a facile hydrothermal method. The reaction products were analyzed via X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), photoelectron spectroscopy(XPS), and UV-Vis diffuse reflectance spectroscopy techniques. Red shift was seen in the absorption band edge peak in the UV-Vis absorbance spectrum with increasing Nd content. The XRD and XPS results confirmed that Nd ions successfully replaced Cd atoms and were incorporated into the crystal lattice of Cd Te. SEM and TEM images indicated spherical structure and high crystallinity. Even at a very low Nd/Cd Te molar ratio of 2 mol.%, Nd doping could greatly enhance the photocatalytic activity of Cd Te. The photocatalytic activity of Nd-doped Cd Te nanoparticles was evaluated by monitoring the decolorization of RRed 43 in aqueous solution under visible-light irradiation. The color removal efficiency of Nd0.08Cd0.92 Te and pure Cd Te were 83.14% and 14.32% after 100 min of treatment, respectively. Among different amounts of the doping agent, 8 mol.% Nd indicated the highest decolorization. The presence of radical scavengers such as Cl-, CO32-, SO42-, and buthanol was found to reduce the decolorization efficiency.     

Visible-Light Excitated Photocatalytic Activity of Rare Earth Metal-Ion-Doped Titania

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Enhanced photocatalytic degradation of organic dyes from aqueous environment using neodymium-doped mesoporous layered double hydroxide

Neodymium-doped Zn–Al layered double hydroxide (Nd/Zn-Al LDH) with excellent photocatalytic activity was prepared by a one-step hydrothermal method. The morphology and physicochemical properties of as-synthesized photocatalysts were well analyzed by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL), UV-diffuse reflectance spectroscopy (UV-DRS), and Brunauer-Emmett-Teller (BET) surface analysis. Doping Nd³⁺ into Zn–Al LDH enhances the overall catalytic activity of the nanocomposite, like better electron–hole pair separation, increase in interplanar distance, fast electron transfer, and large surface area. The as-prepared nanocomposite shows excellent degradation of three different dyes under visible light irradiation. The degradation efficiency of these dyes follows the order of Congo red > rose Bengal > fast green. Furthermore, liquid chromatography-mass spectrometry (LC-MS) was employed to propose a possible photocatalytic degradation pathway for Congo Red and Rose Bengal dyes by Nd/Zn–Al LDH. With the help of radical trapping experiments, it is revealed that during the photoexcitation process, the primary reactive intermediates are hydroxyl radicals.     

铈或钕掺杂TiO2光催化陶瓷及其自洁净抗菌性能研究

采用溶胶-凝胶法和浸渍提拉法在陶瓷表面覆盖了Ce或Nd掺杂的TiO2薄膜.稀土掺杂量为Ce/TiO2=0.007,Nd/TiO2=0.003(摩尔比)时,铈或钕掺杂TiO2光催化陶瓷分别对甲基橙的降解率最大.稀土掺杂TiO2光催化陶瓷对大肠杆菌的抗菌率高达99%,较纯TiO2光催化陶瓷的91%更高.     

花状Pt/Bi2WO6微米晶合成、表征及其高可见光催化性能

利用水热-光化学沉积法合成了一系列粒径为1.5~2μm的花状Pt/Bi2WO6微米晶.采用X射线衍射仪（XRD）、N2物理吸附、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、紫外可见漫反射光谱（DRS）、X射线光电子能谱（XPS）和傅里叶变换红外光谱（FT-IR）等手段进行表征.在可见光照射下（λ＞420 nm）,进行了光催化降解染料酸性橙Ⅱ的性能测试.表征和测试结果表明,这些多尺度花状Pt/Bi2WO6复合微米晶,在水溶液中进行光催化降解反应具有优越的性能.此外,沉积1%的Pt 纳米粒子可使光催化活性显著提高,为Bi2WO6的2.8倍.沉积的Pt纳米粒子由于产生表面等离子体的共振吸收,增强对可见光的吸收能力,同时降低了光生电子（e-）和空穴（h+）的复合,促进·OH 自由基的产生,因此能在很大程度上提高光催化活性.此外,这种特殊结构的Pt/Bi2WO6微米晶有利于在水溶液中进行分离和回收,提高催化剂的利用效率.     

Photocatalytic activity of cerium-doped mesoporous TiO2 coated Fe3O4 magnetic composite under UV and visible light

A novel kind of magnetically separable photocatalyst of cerrium-doped mesoporous titanium dioxide coated magnetite (Ce/MTiO2/ Fe3O4) was prepared and its activities under UV and visible light were reported. The catalysts with Ce/MTiO2 shell and Fe3O4 core were pre-pared by coating photoactive Ce/MTiO2 onto a magnetic Fe3O4 core through the hydrolysis of tetrabutyltitanate (Ti(OBu)4, TBT) with pre-cursors of ammonium ceric nitrate and TBT in the presence of Fe3O4 particles. The MTiO2 shell was for photocatalysis, the Fe3O4 core was for separation by the magnetic field and the doped Ce was used to enhance the photocatalytic activity of MTiO2. The morphological, struc-tural and optical properties of the prepared samples were characterized by Brunauer-Emmett-Teller (BET) surface area, transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-vis absorption spectroscopy. The effect of cerrium-doped content on the photocatalytic activity was studied and the result revealed that 0.5 mol.% Ce/MTiO2/Fe3O4 exhibited highest photoactivity. The photocatalytic activities of obtained photocatalysts under UV and visible light were estimated by measuring the degradation rate of methylene blue (MB, 50 mg/L) in an aqueous solution. The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photooxi-dation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, Ce/MTiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by an external magnetic filed. So, the photocatalyst can be reused without any mass loss. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.     

Facile fabrication of CeF_3/g-C_3N_4 heterojunction photocatalysts with upconversion properties for enhanced photocatalytic desulfurization performance

Cerium fluoride(CeF_3) semiconductor with upconversion property was constructed on graphite carbonitride(g-C_3 N_4) nanosheets by microwave hydrothermal method.The X-ray diffraction,transmission election microscopy,Fourier transform infrared,and X-ray photoelectron spectra techniques were used to characterize the CeF_3/g-C_3 N_4 nanocomposite.The study shows that CeF_3 has upconversion property and can convert visible light(Vis) and near-infrared light(NIR) into ultraviolet light(UV).Mo reover,CeF_3 and g-C_3 N_4 can form well-defined heterojunction and promote the effective separation of photogenerated electrons and holes.The synergistic effect of the CeF_3/g-C_3 N_4 nanocomposite was evaluated by photocatalytic degradation of dibenzothiophene(DBT).The optimum photocatalyst of CeF_3/g-C_3 N_4(40 wt%) composites exhibit the highest photocatalytic desulfurization rate of the model oil under visible light radiation.     

Preparation and characterization of visible-light-driven europium doped mesoporous titania photocatalyst

Pure and different content europium(Eu) doped mesoporous titania were prepared by template method using Eu(NO3)3.6H2O andTi(OC4H9)4 as precursors and Pluronic P123 as template and characterized with X-ray diffraction(XRD),N2 adsorption-desorption measurements,and ultraviolet-visible diffuse absorption spectra.Their photocatalytic activities were studied by photodegradation phenol in water under visible light irradiation.The results showed that Eu doping restrained the growth of grain size and extended the p...     

银掺杂二氧化钛及其光催化性能研究

采用溶胶-凝胶法制备银掺杂二氧化钛光催化剂,通过XRD、SEM、FT-IR、TG-DSC 和UV-Vis等技术对其进行表征.以甲基橙为模拟污染物,考察催化剂的光催化活性,探讨煅烧温度和银掺杂量对光催化效率的影响.实验结果表明：银掺杂二氧化钛提高了二氧化钛在紫外光和可见光下的光催化活性;当Ag掺杂量为1.00%、煅烧温度为450℃、催化剂用量为0.05 g时,银掺杂二氧化钛光催化剂在可见光条件下降解4 h 后,降解率达到92.57%,是纯二氧化钛的4.51倍;紫外光条件下降解2 h达到84.54%,是纯二氧化钛的2.27倍.     

A novel n-CeO_2/n-CdO heterojunction nanocomposite for enhanced photodegradation of organic pollutants under visible light irradiation

In this study,a series of novel visible light driven n-CeO_2/n-CdO heterojunction(CeO_2/CdO)nanoco mposites we re successfully fabricated by simple ultrasonication method.Several characte rization tools including X-ray diffraction(XRD),scanning electro n microscopy(SEM),transmission electron microscopy(TEM)and UV-vis diffuse reflectance spectroscopy(UV-DRS),etc.,were utilized to investigate the physicochemical properties of the catalyst and confirm the formation of heterojunction.Under visible light irradiations,the photocatalytic activities of the as-prepared CeO_2/CdO nanocomposites were evaluated by degrading of Congo red(CR)and Rhodamine B(RhB)solutions.As a result,the CeO_2/CdO(mass percentage ratio 1:3)nanocomposite displays remarkable performance for CR and RhB degradation.The enhancement in the photocatalytic performance of CeO_2/CdO(1:3)nanocomposite can be attributed not only to the strong visible-light absorption region,separating the photogenerated electronhole pairs but also to the formation of n-n type heterojunction.The results also indicate that the CeO_2/CdO(1:3)nanocomposite has good stabilization and high reusability.In addition,the mechanism is proposed for the coupled semiconductors and possible reasons for the enhancement of visible-light photocatalytic efficiency are also discussed.This work can provide a new gateway to fabricate visible photocatalysts and promising candidate catalysts for poisonous wastewater treatment in the near future.     

Enhanced visible light photoactivity of TiO2/SnO2 films by tridoping with Y/F/Ag ions

The Y, F, and Ag tridoped TiO₂/SnO₂ composite nanocrystalline film (YFAg–TS) with prominent photocatalytic performance was prepared by the modified sol–gel method and was characterized by utilizing X-ray diffraction (XRD), differential thermal and thermogravimetric (DTA–TG) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) method, ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), and photoluminescence (PL). The XRD and DTA–TG results expose that the YFAg–TS catalyst is a mixed phase consisting of anatase, rutile, and chlorargyrite, which is beneficial to improving the photocatalytic performance of TiO₂. The SEM, TEM, and BET results disclose that the YFAg–TS film has smaller nanoparticles, higher specific surface area, and narrower pore size compared with pure TiO₂ film. The XRD and TEM results exhibit that a part of yttrium can enter the TiO₂ lattice to induce lattice distortion. The XPS results confirm the presence of Y³⁺ state in the YFAg–TS sample, and Y³⁺ ions can act as the trapping site of electrons to expedite the separation of electrons and holes. The UV–vis DRS results reveal that the YFAg–TS film has an obvious absorption edge shift and a narrower bandgap (2.70 eV) compared with pure TiO₂ film. The PL results show that the YFAg–TS film has the highest photogenerated electrons and holes separation efficiency and charges transfer efficiency among all samples. The photocatalytic activity of the YFAg–TS was assessed by monitoring the degradation of methyl green and formaldehyde solution. The results manifest that the YFAg–TS film has high stability and excellent photocatalytic performance. The possible synergistic photocatalytic mechanism of YFAg–TS films has been discussed in this paper.     

研磨-焙烧法制备BiOI/BiOBr异质结光催化剂及其光催化性能

首先通过沉淀法制备BiOBr和BiOI纳米粉体,然后在主体BiOBr光催化剂中掺杂不同含量的共催化剂BiOI,充分研磨后在不同温度下进行煅烧3 h,制备了BiOI/BiOBr系列复合物,其中BiOI的质量分数分别为1%,2%,4%和8%.采用氮气物理吸附、X射线粉末衍射(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)、紫外-可见(UV-Vis) 漫反射(DRS) 和光电流测试等技术对所制备的样品进行表征.以酸性橙Ⅱ为模拟污染物, 在可见光下考察了煅烧温度和BiOI复合含量对BiOBr主体光催化剂的光催化性能的影响.研究表明,当复合BiOI的含量为4%,煅烧温度为400 ℃时所制备的复合光催化剂表现出最高光催化性能,其降解效率分别是纯BiOBr和BiOI的1.7和1.9倍.复合BiOI促进了催化剂对可见光的吸收,同时经过研磨和煅烧形成的BiOI/BiOBr异质相结,促进了光生电子(e-) 和空穴(h+) 的分离,提高了光催化活性.      

微波水热法快速合成氧化锌纳米棒及其光催化性能

以硫酸锌、醋酸锌和氢氧化锌为原料,制备出氢氧化锌前驱体和氧化锌晶种,在微波水热条件下快速合成了氧化锌纳米棒。通过X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）和紫外?可见分光光度计（UV-vis）对氧化锌纳米棒的形貌、结构和光学性质等进行了表征,并通过降解罗丹明B（RhB）测试了样品的光催化性能,探讨了微波辐射作用对产物的催化活性的影响。实验结果表明,氢氧化锌作为前驱体在微波作用下30 min,生成为基于氧化锌纳米棒自组装的三维笼状结构,与常规方法制备的氧化锌纳米棒相比,微波辐射作用下生成的样品结晶度更高。紫外?可见分光光度计结果表明微波辐射会导致合成的氧化锌纳米棒吸收边红移,缩小带隙能量,从而提升氧化锌纳米棒的催化活性。光催化测试表明微波辅助合成的氧化锌纳米棒具有更好的可见光吸收特性,在紫外和可见光照射下,对罗丹明B都具有较好的降解效率,在紫外光照射下80 min内罗丹明B的降解率可达到98.5%。这种微波辅助的合成方法能够在短时间内合成大量的氧化锌纳米材料,具有高效批量制备、清洁环保等优点。      

Preparation of Nano-TiO2 Doped with Cerium and Its Photocatalytic Activity

Cerium-doped titanium dioxide nano-powders were prepared through the sol-gel method and the compound sampies were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, and UV/Vis diffuse reflectance spectra （DRS）. The photocatalytic activity was evaluated by photocatalytic degradation of phenol in water. The results of XRD, TEM, and DRS show that pure TiO2 and Ce-doped TiO2 powder crystallines are a mixture of anatase and rutile ; the doping can retard the development of the grain size of TiO2 and decrease the diameter of TiO2 from more than 20 nm of pure TiO2 to about 10 nm; the doped TiO2 can improve the light absorption of TiO2 and suitable doping content tends to move the DRS spectrum of TiO2 towards visible light, but too much doping is not good for the light absorption ability. The results of the photocatalytic experiments show that doping with Ce content of 0.08% -0.4% can increase the photocatalytic activity of TiO2; however, doping with Ce content of 0.5% -2.5% can significantly decrease the photocatalytic activity of TiO2. The favorite doping content is 0.4% in the range of our experiments.     

可见光活性的Ru掺杂TiO2光催化剂的制备及光解水制氢性能研究

采用溶胶—凝胶法制备了系列Ru掺杂TiO2光催化剂,并利用XRD和UV-Vis漫反射光谱对样品进行了表征。结果表明:Ru掺杂阻止了TiO2纳米粒子由锐钛矿向金红石相的转变,提高了TiO2对可见光的吸收强度。Ru掺杂的最佳浓度为0.014%,在可见光的照射下,Ru(0.014%)/TiO2对光解水制氢有较高的活性。     

锐钛矿型纳米TiO2溶胶的低温制备及其光催化活性评价

研究了以四氯化钛和氨水为原料,在常温下通过两步法制备TiO2溶胶。TEM和XRD分析表明,TiO2溶胶粒径小于10 nm,并存在一定数量的锐钛矿型晶相结构。自然光照条件下,通过对亚甲基蓝水溶液的光催化降解试验和对新鲜馒头的防霉试验,考察了TiO2溶胶的光催化活性,同时检验了TiO2溶胶的稳定性。结果表明,TiO2溶胶具有较好的光催化活性和稳定性。     

Effects of Nd Doping on Magnetic-Optical Properties of GdFeCo Thin Films

The GdFeCo and NdGdFeCo thin films were prepared by sputtering, and their hysteresis loops, the temperature dependence of the saturation magnetization Ms and the magneto-optical Kerr spectrum in the visible light range were measured. By studying the effects of light rare earth element Nd doping on the magneto-optical Kerr rotation angle of GdFeCo thin films, it is found that proper Nd additives in GdFeCo films could enhance Kerr rotation at short wavelengths. So it could be better medium used as the readout layer of center aperture detection magnetically induced super resolution （CAD-MSR）.     

纳米TiO2薄膜的制备及自清洁性能研究

通过溶胶一凝胶法在普通钠钙玻璃表面制备均匀透明的纳米TiO2自清洁薄膜。探讨了薄膜制备的工艺条件，并利用X射线衍射（XRD）、紫外分光光度计对薄膜的晶型、晶粒大小和透光率进行了表征，研究了在紫外光照射下薄膜的光催化性能及亲水性能。结果表明，制得的TiO2薄膜具有较强的自清洁性能。     

Lanthanide complexes-functionalized ordered mesoporous TiO2: Multicolor emission (visible and near-infrared luminescence) based on visible-light sensitization

Recently, much attention has been paid to the lanthanide luminescent materials based on the visible-light sensitization for their potential applications in the fields of bio-imaging and optical devices. In this work, the lanthanide complexes have been covalently bonded to the ordered mesoporous titania (OMT) matrix, and the resulting titania-based hybrid ordered mesoporous materials (named as LnDB-OMT, Ln = Eu, Sm, Yb, Nd) were characterized by using Fourier-transform infrared (FT-IR) spectroscopy, small-angle X-ray powder diffraction (SAXD), N₂ adsorption–desorption isotherms, transmission electron microscopy (TEM), fluorescence spectroscopy, and thermogravimetric analysis. Generally, exciting with visible light is advantageous over UV excitation. Of importance here is that, under excitation with visible light, the LnDB-OMT all show characteristic visible (Eu³⁺, Sm³⁺) as well as near-infrared (Sm³⁺, Yb³⁺, Nd³⁺) luminescence of the corresponding Ln³⁺ ions (multicolor emission covered from 500 to 1400 nm spectral region), which is attributed to the energy transfer from the ligands to the Ln³⁺ ions via an antenna effect.