反溶剂沉淀法合成Fe~(3+)掺杂ZnO纳米结构及其可见光催化性能

以氯化胆碱-草酸低共熔溶剂(ChCl-OA DES)为溶剂,ZnO和Fe_2O_3为原料,通过简单的反溶剂沉淀法制备出不同掺杂浓度的Fe~(3+)掺杂ZnO (Fe-ZnO)纳米结构。采用SEM、XRD、拉曼光谱、XPS等手段对所制Fe-ZnO结构与形貌进行了表征。结果表明,Fe-ZnO是由直径为20～30 nm纳米晶组装而成的微米棒。不同掺杂浓度的Fe-ZnO纳米晶均为六方铅锌矿结构,Fe~(3+)很好地进入ZnO晶格。同时考察了所制Fe-ZnO的光吸收特性和光催化活性,发现Fe~(3+)掺杂使其吸收峰红移至可见光范围,有效增强了可见光区域的催化活性。当Fe掺杂量为1.0%(atom)时,样品的光催化活性最好,比ZnO增大了约102倍。这说明Fe~(3+)掺杂可改善ZnO对可见光光子的捕获能力。     

稀土掺杂ZnO纳米材料的制备与表征

采用超声化学法，以六水合硝酸锌、六水合硝酸铕和三乙醇胺为原料，在加入聚乙二醇20000的水中进行反应，制备了呈球状的纳米ZnO:Dy³⁺。采用微波水热法制备ZnO:Eu³⁺纳米材料。采用X射线衍射(XRD)、场致发射扫描电镜(SEM)、紫外-可见光谱(UV-Vis)、光致发光谱(PL)等技术对所制备的样品进行了系列表征。结果表明：掺杂后并未改变纳米颗粒的晶型结构，紫外-可见吸收光谱显示其在紫外、可见光区域的吸收能力均有所增强；荧光光谱显示在紫外、可见光区存在多个发光峰，掺杂后发光强度增强。     

锡掺杂溴铅铯钙钛矿纳米晶的合成、结构及发光性能

为了降低CsPbBr₃钙钛矿纳米晶的Pb²⁺毒性，同时优化Sn²⁺掺杂CsPbBr₃纳米晶的发光性能，采用热注入法合成了Sn²⁺掺杂的Cs Pb_1-xSn_x Br₃纳米晶(x=0.1、0.2、0.3、0.4和0.5)，使用X射线衍射仪(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和荧光光谱仪(PL)对所合成纳米晶的物相结构、微观形貌及发光性能进行表征。结果表明，纳米晶中掺杂的Sn元素以Sn²⁺和Sn⁴⁺形式存在，且含有Pb²⁺阳离子空位，当x=0.3时，Sn元素实际掺杂物质的量分数高达43.91%。x=0.1～0.4时，纳米晶为纯单斜相钙钛矿结构，尺寸约16～20 nm，立方块形貌较均匀。Sn²⁺掺杂调控了Cs Pb_1-xSn_x Br₃纳米晶的...     

稀土离子掺杂钒酸铋纳米晶的制备、晶体结构特征及光谱性质

采用化学溶液法合成了不同稀土离子(Nd³⁺、Y³⁺、Eu³⁺)掺杂的BiVO₄纳米晶。利用X射线衍射分析、扫描电子显微分析、能量色散X射线光谱、Fourier红外光谱、Raman光谱、紫外-可见光漫反射光谱以及荧光光谱研究了样品的物相、晶体结构、成分、形貌、局部结构、表面化学和光谱性质。结果表明:不同离子掺杂的BiVO₄样品尺寸处于纳米尺度,不同离子掺杂的BiVO₄纳米晶具有四方相晶体结构,这些纳米晶呈现出清晰的轮廓及规则的形貌,表明得到的纳米晶具有较好的结晶性能,且表现出一定程度的晶格畸变。在247、367、763、855 cm^-1附近出现的掺杂BiVO₄纳米晶的拉曼峰,与四方相BiVO₄结构的振动频率相吻合。紫外-可见光漫反射光谱表明,随着掺杂离子的引入,BiVO₄纳米晶样品内部电子结构发生了变化,BiVO₄、Eu:BiVO₄     

TBAH/H2O溶解体系中(Fe)Ⅲ对纤维素溶解性能的影响

四丁基氢氧化铵(TBAH)水溶液是一种常温非衍生化高效溶解纤维素的新型溶剂体系。通过引入一定浓度Fe³⁺研究了生产过程中体系中(Fe)Ⅲ对纤维素溶解性能以及再生纤维素膜力学性能的影响规律。结果表明，在较低的浓度范围内，Fe³⁺能够促进纤维素的溶解，Fe³⁺浓度从0增加到50 ppm时，纤维素溶液浊度从32.2 NTU降低至14.8 NTU，粘度从62.3 Pa·s升至71 Pa·s；再生纤维膜断裂强度从45 MPa提高到98 MPa，断裂伸长率也从15.1%提高到18.7%。鉴于(Fe)Ⅲ在实际生产中不可避免，本研究对于纤维素新型溶剂纺实际生产过程中产品质量控制具有重要的指导意义。     

Fe3+掺杂CaZrT2iO7色料的制备及近红外反射性能研究

采用高温固相法合成了一种新型无机色料CaZrTi_2-xFe_xO₇ (x=0,0.1,0.2,0.3,0.4),并利用X射线衍射仪(XRD)、固体紫外/可见光/近红外分光光度计、色度测试仪、酸碱稳定性测试等对掺杂钙钛锆石的晶相结构、光谱性质以及耐酸碱性进行了分析表征。结果表明:Fe³⁺的掺杂并未改变钙钛锆石的晶体结构,主要仍为钙钛锆石相。随着Fe³⁺掺杂量的增加,色料颜色由灰白色逐渐转变为黄色、暗橙色,红色指标a^*和黄色指标b^*均有所增加,当掺杂量x为0.4时,具有最高的黄度值,b^*约为28.9。此外,未掺杂的色料具有85.3%的最高近红外反射率,且随着掺杂量的增加,近红外反射率有所降低,但仍保持较高的近红外反射率。     

Fe—ZnO／SnO2的制备及可见光催化性能研究

以硝酸锌、氯化锡、硝酸铁等为原料，采用共沉淀法成功合成铁掺杂的ZnO/SnO2光催化剂（Fe-ZnO/SnO2）。使用卤钨灯作为可见光光源，罗丹明B为模拟污染物，得出Fe-ZnO/SnO2具有良好的可见光催化活性。并利用X射线衍射、紫外-可见漫反射、扫描电镜等测试手段对Fe-ZnO/SnO2进行表征，分析其光催化相关机制。     

氮掺杂碳点的制备及其在Fe3+检测中的应用

以含氮的三羟甲基氨基甲烷为碳源,采用水热法制备了水溶性良好的氮掺杂碳点(N-CDs)。通过荧光光谱、紫外-可见光谱、傅里叶红外光谱、场发射透射电镜和X射线光电子能谱,对制备的N-CDs的结构和光学性质进行了表征,研究了p H和含盐量对N-CDs荧光性能的影响,并以N-CDs为荧光探针,检测水中的Fe³⁺。结果表明,制备的N-CDs分散性好,水溶性好,尺寸均一,平均粒径为6.1 nm,具有较好的p H稳定性和耐盐性。Fe³⁺对制备的N-CDs具有荧光猝灭效应,在0.1～80μmol·L^-1的Fe³⁺浓度范围内,N-CDs荧光强度的降低与Fe³⁺浓度具有良好的线性关系,线性方程为ΔF=1.0001C+18.9646,相关系数R²为0.9932。制备的N-CDs具有制备简单、成本低、检测灵敏度高等优点,可作为荧光探针用于检测水中微量的Fe³⁺,具有潜在的应用前景。     

NaYF4∶Yb3+,Tm3+稀土掺杂上转换纳米材料的制备与条件优化

利用溶剂热法制备油相NaYF₄∶Yb³⁺,Tm³⁺,经“超声去油”后得到水相NaYF₄∶Yb³⁺,Tm³⁺,并对稀土离子掺杂比例、反应温度、反应时间和油酸体积分数进行条件优化，通过X-射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)和分子荧光光谱仪(MFS)对其进行表征。结果表明，当稀土离子掺杂比例为NaYF₄∶25%Yb³⁺,0.3%Tm³⁺,反应时间为60 min,反应温度为300℃,油酸体积分数为20.6%时，合成的水相NaYF₄∶Yb³⁺,Tm³⁺为六方晶型结构，六边形两平面间的平均粒径大小约为50 nm,形貌均匀、尺寸均一、分散性良好，980 nm近红外光激发下，在452和478 nm处荧光强度最大，且发出明亮的蓝色荧光。水相NaYF₄∶Yb³⁺,Tm...     

溶剂热法制备Ca0.65La0.35F2.35:Yb3+/Er3+及其发光性能的研究

以油酸，辛醇和乙二醇作为溶剂体系，采用溶剂热法合成出Yb/Er共掺杂的Ca_0.65La_0.35F_2.35上转换纳米颗粒。通过改变前驱体Yb³⁺浓度制备样品，并借助使用X-射线衍射仪(XRD)、荧光光谱仪和扫描电镜(SEM)对颗粒进行表征，结果表明，当Yb³⁺离子浓度为20%时，得到红光发射较强的立方相的Ca_0.65La_0.35F_2.35,样品形貌较均匀，尺寸小。因此在生物成像、检测等领域具有潜在的应用价值。     

Hydrothermal doping method for preparation of Cr-TiO2 photocatalysts with concentration gradient distribution of Cr

Cr³⁺-doped anatase titanium dioxide photocatalysts were prepared by the combination of sol–gel process with hydrothermal treatment. The samples were characterized by UV–vis diffuse reflectance spectroscopy, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area (S_BET), transmission electron microscopy (TEM), atomic absorption flame emission spectroscopy (AAS), electron paramagnetic resonance (EPR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was confirmed that Cr substitutes Ti⁴⁺ in TiO₂ lattice in trivalent ionic state, and the concentrations of dopants Cr³⁺ decrease from the exterior to the interior of doped TiO₂. The photocatalytic activity of Cr-TiO₂ was investigated for the photocatalytic degradation of XRG aqueous solution both under UV and visible light irradiation. Due to the excitation of 3d electron of Cr³⁺ to the conduction band of TiO₂, Cr-TiO₂ shows a good ability for absorbing the visible light to degrade XRG. Doping of chromium ions effectively improves the photocatalytic activity under both UV light irradiation and visible light irradiation with an optimal doping concentration of 0.15% and 0.2%, respectively. The special distribution of dopants Cr³⁺ seems having a good effect on enhancing the photocatalytic activity of Cr-TiO₂.     

Synthesis of hierarchical dendritic micro–nano structure ZnFe_2O_4 and photocatalytic activities for water splitting

Hierarchical dendritic micro–nano structure Zn Fe_2O_4 have been prepared by electrochemical reduction and thermal oxidation method in this work. X-ray diffractometry, Raman spectra and field-emission scanning electron microscopy were used to characterize the crystal structure, size and morphology. The results show that the sample(S-2) is composed of pure ZnFe_2O_4 when the molar ratio of Zn~(2+)/Fe~(2+)in the electrolyte is 0.35. Decreasing the molar ratio of Zn~(2+)/Fe~(2+), the sample(S-1) is composed of ZnFe_2O_4 and α-Fe_2O_3, whereas increasing the molar ratio of Zn~(2+)/Fe~(2+), the sample(S-3) is composed of ZnFe_2O_4 and Zn O. The lattice parameters of ZnFe_2O_4 are influenced by the molar ratio of Zn~(2+)/Fe: Zn at excess decreases the cell volume whereas Fe at excess increases the cell volume of Zn Fe_2O_4. All the samples have the dendritic structure, of which S-2 has micron-sized lush branches with nano-sized leaves. UV–Vis diffuse reflectance spectra were acquired by a spectrophotometer. The absorption edges gradually blue shift with the increase of the molar ratio of Zn~(2+)/Fe~(2+). Photocatalytic activities for water splitting were investigated under Xe light irradiation in an aqueous olution containing 0.1 mol·L~(-1)Na_2S/0.02 mol·L~(-1)Na_2SO_3 in a glass reactor. The relatively highest photocatalytic activity with 1.41 μmol·h-1· 0.02 g~(-1)was achieved by pure ZnFe_2O_4sample(S-2). The photocatalytic activity of the mixture phase of Zn Fe_2O_4 and α-Fe_2O_3(S-1) is better than ZnF e_2O_4 and ZnO(S-3).     

Fe/Fe cycling promoted by Ta3N5 under visible irradiation in Fenton degradation of organic pollutants

Ta₃N₅ was synthesized by nitridation of Ta₂O₅ under NH₃ flow at 700 °C. The catalyst was pure Ta₃N₅ according to X-ray diffraction (XRD), and was about 5 nm in size with a BET specific surface area 52.8 m²/g. When Ta₃N₅ was added to Fe³⁺/H₂O₂ solution (known as Fenton-like system), most Fe³⁺ were adsorbed on the Ta₃N₅ surface and could not react with H₂O₂ in the dark, which is different from the general Fenton reaction. Under visible light irradiation, adsorbed Fe³⁺ ions were reduced to Fe²⁺ rapidly and Fe²⁺ were reoxidized by H₂O₂ on the Ta₃N₅ surface, thus a fast Fe³⁺/Fe²⁺ cycling was established. Kinetics and ESR measurements supported this mechanism. The Ta₃N₅/Fe³⁺/H₂O₂ system could efficiently decompose H₂O₂ to generate hydroxyl radicals driven by visible light, which could accelerate significantly the degradation of organic molecules such as N,N-dimethylaniline (DMA), and 2,4-dichlorophenol (DCP). A mechanism was proposed for iron cycling on the basis of experimental results.     

不同水解抑制剂下Sr2+掺杂改性纳米TiO2的制备及可见光响应行为

采用溶胶-凝胶法,以钛酸丁酯为钛源,分别以三乙醇胺和亚氨基二乙酸为水解抑制剂,制备掺杂不同含量Sr²⁺的纳米TiO₂,并对其在可见光范围内对孔雀石绿的光催化降解活性进行评价。结果表明,Sr²⁺掺杂能够有效提高纳米TiO₂的光催化性能,并确定不同条件下合成的纳米TiO₂的最佳掺杂量和反应条件。对掺杂的TiO₂进行紫外可见漫反射光谱、X射线衍射、傅里叶变换红外光谱以及氮物理等温吸附等表征,揭示了表面性能、电子结构、脱水性能、吸附性能、结晶程度和晶相结构等多方面协同作用是Sr²⁺掺杂的TiO₂具有最高光催化活性的原因。这种新型光催化剂可能在环境净化和水处理方面具有一定的应用价值。     

Photocatalytic degradation of organic compounds diluted in water using visible light-responsive metal ion-implanted TiO2 catalysts: Fe ion-implanted TiO2

The application of metal ion-implantation method has been made to improve the electronic properties of the TiO₂ photocatalyst to realize the utilization of visible light. The photocatalytic properties of these unique TiO₂ photocatalysts for the purification of water have been investigated. By the metal ion-implantation method, metal ions (Fe⁺, Mn⁺, V⁺, etc.) are accelerated enough to have the high kinetic energy (150 keV) and can be implanted into the bulk of TiO₂. TiO₂ photocatalysts which can absorb visible light and work as a photocatalyst efficiently under visible light irradiation were successfully prepared using this advanced technique. The UV-Vis absorption spectra of these metal ion-implanted TiO₂ photocatalysts were found to shift toward visible light regions depending on the amount and the kind of metal ions implanted. They were found to exhibit an effective photocatalytic reactivity for the liquid-phase degradation of 2-propanol diluted in water at 295 K under visible light (λ>450 nm) irradiation. The investigation using XAFS analysis suggested that the substitution of Ti ions in TiO₂ lattice with implanted metal ions is important to modify TiO₂ to be able to adsorb visible light.     

Fe3+在A2O工艺缺氧区的转化规律及其对污泥絮凝性的影响

为了研究铁元素对A²O工艺污泥絮凝性的影响,考察Fe³⁺在污泥上清液、胞外聚合物（extracellular polymeric substances,EPS）与底泥（Pellet）中的分布和迁移转化规律,结合三维荧光光谱（3D-EEM）、原子吸收和X射线衍射仪（XRD）分析Fe的存在形态和结构特征,揭示Fe³⁺与微生物代谢产物的作用机制,探索Fe³⁺对脱氮除磷效率的影响。结果表明：低浓度Fe³⁺（<10 mg·L^-1）能够提高COD和TN去除率,促进微生物活性,增强污泥生物絮凝性;高浓度Fe³⁺（10~40 mg·L^-1）则抑制微生物活性,使EPS总量升高,污泥絮体脱稳,LB、TB层PN/PS是影响污泥絮凝性的关键因素;Fe³⁺的投加强化生物除磷效率,当Fe³⁺浓度为40 mg·L^-1时,TP去除率为93%。Fe³⁺在污泥混合液中的分布规律为TB>上清液>LB>SMP,Fe³⁺在生物体内富集累积,能够改变EPS各层的组分。     

Ultrafiltration recovery of alginate: Membrane fouling mitigation by multivalent metal ions and properties of recycled materials

Recovery of alginate extracted from aerobic granular sludge (AGS) has given rise to a novel research direction. However, these extracted alginate solutions have a water content of nearly 100%. Alternately, ultrafiltration (UF) is generally used for concentration of polymers. Furthermore, the introduction of multivalent metal ions into alginate may provide a promising method for the development of novel nanomaterials. In this study, membrane fouling mitigation by multivalent metal ions, both individually and in combination, and properties of recycled materials were investigated for UF recovery of sodium alginate (SA). The filtration resistance showed a significantly negative correlation with the concentration of metal ions, arranged in the order of Mg²⁺ < Ca²⁺ < Fe³⁺ < Al³⁺ (filtration resistance mitigation), and the moisture content of recycled filter cake showed a marked decrease. For Ca²⁺, Mg²⁺, Fe³⁺, and Ca²⁺+Fe³⁺, the filtration resistances were almost the same when the total charge concentration was less than 5 mmol·L^-1. However, when the total charge concentration was greater than 5 mmol·L^-1, membrane fouling mitigation increased significantly in the presence of Ca²⁺ or Fe³⁺ and remained constant for Mg²⁺ with the increase of total charge concentration. The filtration resistance mitigation was arranged in the order of Fe³⁺ > Fe³⁺ + Ca²⁺ > Ca²⁺ > Mg²⁺. Three mechanisms were proposed in the presence of Fe³⁺, such as the decrease of SA concentration, change in pH, and production of hydroxide iron colloids from hydrolysis. The properties of recycled materials (filter cake) were investigated via optical microscope observation, dynamic light scattering, Fourier transform infrared, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy. The results provide further insight into UF recoveries of alginate extracted from AGS.     

Facile synthesis and enhanced visible-light photocatalytic activity of Ti3+-doped TiO2 sheets with tunable phase composition? ?

Ti³⁺-doped TiO₂ nanosheets with tunable phase composition (doped TiO₂ (A/R)) were synthesized via a hydrothermal method with high surface area anatase TiO₂ nanosheets TiO₂ (A) as a substrate, structure directing agent, and inhibitor; the activity was evaluated using a probe reaction-photocatalytic CO₂ conversion to methane under visible light irradiation with H₂ as an electron donor and hydrogen source. High-resolution transmission electron microscope (HRTEM), field emission scanning electron microscope, UV-Vis diffuse reflectance spectra, and X-ray diffraction (XRD) etc., were used to characterize the photocatalysts. XRD and HRTEM measurements confirmed the existence of anatase-rutile phase junction, while Ti³⁺ and single-electron-trapped oxygen vacancy in the doped TiO₂ (A/R) photocatalyst were revealed byelectron paramagnetic resonance (EPR) measurements. Effects of hydrothermal synthesis temperature and the amount of added anatase TiO₂ on the photocatalytic activity were elucidated. Significantly enhanced photocatalytic activity of doped TiO₂ (A/R) was observed; under the optimized synthesis conditions, CH₄ generation rate of doped TiO₂ (A/R) was 2.3 times that of Ti³⁺-doped rutile TiO₂.     

Growth Kinetic and Characterization of RF-Sputtered ZnO:Al Nanostructures

ZnO:Al nanostructures with 1% by mole of Al were prepared by radio frequency sputtering on copper and quartz substrates. The ZnO:Al nanostructures obtained exhibited needle- or tree-like structures with the diameter ranging from 30 to 100 nm. It was suggested that these ZnO:Al nanostructures could be single-crystalline hexagonal structures growing along the     direction with branching along the 〈0001〉 direction. From Hall measurement, ZnO:Al nanostructures had a resistivity in the order of 10⁻²Ω·cm, a carrier concentration of 10²⁰ cm⁻³, and a Hall mobility of 3 cm²·(V·s)⁻¹. From X-ray diffraction, transmission electron microscopy and Raman results, ZnO:Al nanostructures had     direction perpendicular to the surface, whereas ZnO nanobelts had the c -axis perpendicular to the surface. In addition, the growth mechanism of the wire and belt-like nanostructure could be explained by kinetics of anisotropic growth via a vapor–solid mechanism. This information would be useful for further applications of ZnO:Al nanostructures.     

Kinetics and Modeling of Chemical Leaching of Sphalerite Concentrate Using Ferric Iron in a Redox-controlled Reactor

This work presents a study for chemical leaching of sphalerite concentrate under various constant Fe3+concentrations and redox potential conditions. The effects of Fe3+ concentration and redox potentia...