Photocatalytic degradation of Rhodamine B under visible light with Nd-doped titanium dioxide films

Microporous titanium dioxide films were prepared by the sol-gel methods on glass substrates, using tetrabutyl titanate as source material. In order to absorb the visible light and increase the photocatalytic activities, different concentrations of neodymium ions (Nd/Ti molar ratio was 0.5%, 0.7%, 0.9%, and 1.1% respectively) were added into the sol. X-ray diffraction (XRD), X-ray photoelectron spectros-copy (XPS), and atom force microscopy (AFM) were applied to characterize the modified films. A kind of typical textile industry pollutant (Rhodamine B) was used to evaluate the photocatalytic activities of the films under visible light. The results showed that the activities of the films were improved by doping Nd ions into the sol.

Preparation and characterization of nitrogen-doped titanium dioxides

A type of high visible-light active titanium oxinitride(TiO2-xNx) powder was prepared by a simple proc-ess:the calcination of the hydrated titanium dioxide at the atmosphere of ammonia-argon using a tu-bular electric furnace at high temperatures. The hydrated titanium dioxide was synthesized as the precursor of TiO2-xNx using titanic acid as raw material,which came from sulfate technique of produc-ing titanium white. The effects of temperature and reaction time on the nitrogen content,grain size and crystal structure were studied. The visible-light activity and photocatalysis capability of the powder were also investigated.

Photocatalytic Activity of Nanosized TiO_2 Enhanced by co-doping with Fe^(3+) and Nd^(3+) Ions

In this study, nanosized TiO2 co-doped with Fe3+ and Nd3+ ions was synthesized via a sol-gel method. The metallic ion doped TiO2 was thoroughly characterized with XRD and UV-vis, and the photocatalytic activity was evaluated by degrading methylene blue (MB) solution. The results indicated that TiO2 crystalline size was reduced and phase transformation of anatase to rutile was suppressed as the content of doped Nd3+ ion increased in the co-doped TiO2. The UV-vis spectra of co-doped TiO2 seemed to simply overlay two spectra of single metal doped TiO2, and had significantly increased absorbance in the ranges of 400～500 nm, 565～600 nm and 730～765 nm as compared to pure TiO2. The photocatalytic activity of co-doped TiO2 was obviously enhanced, and raised about 30% compared to that of pure TiO2 as doped Nd3+ content was 0.15% and Fe3+ content was 0.05%, respectively. The enhanced catalytic activity was attributed to a synergistic effect of two doped ions, where doped Fe3+ ion inhibited the recombination of photogenerated electron and hole, and Nd3+ ion brought more surface carboxyl to promote the degradation reaction.

Preparation and visible-light photocatalytic property of nanostructured Fe-doped TiO_2 from titanium containing electric furnace molten slag

Nanostructured Fe-doped titanium dioxide was synthesized from titanium containing electric furnace molten slag （TCEFMS） by using an alkali fusion, followed by a hydrolyzation-acidolysis-cMcination route. The effects of Mkali/slag mass ratio, calcinating temperature, calcinating time, and water/slag mass ratio on the extraction efficiency and purity of products were systematically studied in this paper. It is indicated that the best extraction efficiency of nanostructured Fe- doped titanium dioxide is 99.35%, when the molten slag is calcinated at 700℃ for 1 h with the mass ratio of alkali/molten slag of 1.5：1. The influence of alkali/slag mass ratio on the photocatalytic activity of final products was evaluated by the photodegradation of methyl blue under visible light irradiation. A maximum photodegradation efficiency of 88.12% over 30 min was achieved under the optimum conditions.

Effects of N Doping on the Microstructures and Optical Properties of TiO_2

TiO_2 nanopowders with different nitrogen(N) dopant concentrations were first synthesized by sol-gel method. XRD, TEM, HRTEM, XPS, UV-vis DRS were used to characterize the effects of N doping on the microstructures and optical properties of TiO_2. The results indicated that the prepared TiO_2 only contained anatase phase with a slight distortion, and the N doping improved the dispersity of TiO_2. The N doping leaded to more defects in TiO_2, capturing the charge carriers and inhibiting the combination of electrons and holes. Also, the N-doped TiO_2 was composed of Ti, O and N. Further, N was doped into the TiO_2 lattice by substituting for O, forming the oxidized nitrogen in the form of Ti–N–O or Ti–O–N bond, and Ti was present in the form of Ti^(4+) in TiO_2. Finally, the absorbance of N-doped TiO_2 was obviously improved in both UV and visible light region. Optical absorption edges of N-doped TiO_2 samples showed obvious red shift, which expanded spectral absorption range of TiO_2 and improved the utilization efficiency of visible light. It is concluded that N element was successfully doped into TiO_2 crystal lattice, and the N dopant concentration of 3.0% was designed to modify Ti O2.

Antibacterial Properties of V-doped Titanium-bearing Blast Furnace Slag Prepared at Different Calcination Temperatures

Perovskite-type V-doped titanium-bearing blast furnace slag (VTBBFS) photocatalyst was prepared by high-temperature solid phase method.The influence of calcination temperature on the photocatalytic and antibacterial properties of VTBBFS was studied in details.Its composition and microstructure were evaluated by X-ray diffractometer,ultraviolet-visible absorption spectrometer,Fourier transform infrared spectrometer and scanning electron microscope.The antibacterial properties of VTBBFS to Candida albicans were investigated by flask oscillation method.The results showed that the optical absorption and antibacterial properties of VTBBFS were the best with 10%(ω) doping of vanadium,prepared at 800℃ for 2 h,and its sterilization rate was close to 100% to Candida albicans (ATCC10231).The minimum inhibitory and minimum bactericidal concentrations were 25 and 50 mg/mL.When the concentration was 0.2 μg/mL,the catalyst had the least toxic toxicity.

Fe-TiO_(2)光催化降解乙烯及其影响樱桃番茄果实采后后熟的应用初探

樱桃番茄属于呼吸跃变型果蔬,采后易受乙烯影响加速果实的呼吸作用和后熟进程,严重缩短果实货架期。因此,开发可清除樱桃番茄采后环境中乙烯的包装材料,对于减少果实采后因乙烯催熟而引起的经济损失有重要的现实意义。该研究采用煅烧法制得一种在可见光照射条件下具有光催化活性的铁掺杂二氧化钛光催化剂(Fe-TiO_(2)),与纯二氧化钛(TiO_(2))纳米颗粒相比,Fe-TiO_(2)禁带宽度减小、光生电子-空穴对复合率降低,在LED灯光照条件下乙烯降解率大幅度提高。将其通过涂膜处理应用于樱桃番茄采后保鲜中,以果实表面色泽的变化判断其后熟进程,探究在LED灯光照条件下Fe-TiO_(2)对樱桃番茄采后后熟的影响。结果表明,与对照组相比,LED灯光照下,Fe-TiO_(2)负载于聚乙烯醇中的涂膜处理有效减缓樱桃番茄绿熟果实转红的速度,约推迟4 d,显著延缓果实采后后熟进程,初步展示光催化降解乙烯在果蔬采后保鲜上的应用前景。

Preparation and photocatalytic properties of Fe-doped TiO_2 nanoparticles

Nanocrystalline Fe-doped TiO2 with size of 6070 nm was prepared by a sol-gel technique, followed by freeze-drying treatment for 2 h. Thermogravimetric and differential thermal analyses, X-ray diffraction, scanning （electron） microscope, laser diffraction particle size analyzer and UV-Vis spectrophotometer technologies were used to characterize the product. The photocatalytic activities of the samples were evaluated by the degradation of wastewater of paper-making. The effects of Fe ion implantation on the photocatalytic activity of TiO2 were also discussed. The results show that the iron content plays an essential role in affecting the photocatalytic activity of the Fe-doped TiO2 and the optimum content of Fe-doped is 0.05% （mass fraction）. The photocatalytic activity of samples with lower content of Fe-doped is higher than that of pure TiO2 in the treatment of paper-making wastewater. The photo-degradation effect of paper-making effluent is the best by means of Fe-doped TiO2 with 0.05% Fe.

锌离子电池锰基正极材料研究进展

可充电水系锌离子电池是一种环保且电化学性能优异的二次电池,但锰基正极材料在充放电过程中结构易坍塌、导电率低、稳定性差等缺点严重制约了水系锌离子电池的发展。笔者首先阐述了锰基正极材料中锌离子的储存机理,主要有Zn^(2+)嵌入/脱出机理、H+/Zn^(2+)共嵌入/脱出机理和化学转化反应机理。Zn^(2+)嵌入/脱出机理包括无相变反应和新相生成反应。而新相生成反应又分为可逆相变和不可逆相变。然后,基于锰基正极材料面临的问题,讨论了改善其储锌性能的主要方法。目前可采用的方法包括缺陷工程、与导电材料复合、离子掺杂、表面修饰技术等。用以上方法改进后的锰基正极材料表现出了更加优异的性能。

Preparation and characterization of (metal, nitrogen)-codoped TiO_2 by TiCl_4 sol-gel auto-igniting synthesis

The nitrogen-doped and （metal, nitrogen）-codoped TiO2 photocatalysts （metal = Ag, Ce, Fe, La） were synthesized by sol-gel auto-igniting synthesis （SAS） with the complex compound sol of TiCl4-NH4NO3-citri acid-metal nitrate- NH3.H20 as a precursor. The products were characterized by means of XRD, XPS, and UV-Vis diffuse reflectance spectra, and their photocatalytic activity was investigated under visible light. It was found that all the synthesized powders showed good absorption for visible light, and that the radius and alterable valence states of doping metallic cations played important roles on their photocatalytic activity. These results were discussed in detail.

Preparation of V-doped TiO_2 Photocatalysts by the Solution Combustion Method and Their Visible Light Photocatalysis Activities

A series of nanocrystalline V-doped （0.0-3.0 at.%） TiO2 catalysts have been successfully prepared by the one-step solution combustion method using urea as a fuel. The obtained powders were characterized by XRD, SEM, Raman, XPS and UV-Vis DRS. The effects of V doping concentration on the phase structure and photocatalytic properties were investigated. XRD, Raman, and XPS show that V doping diffuses into TiO2 crystal lattice mainly in the form of V5＋ and causes a phase transition from anatase to mille. V doping can widen the light absorption range of TiO2, with the absorption threshold wavelength shifting from 425 to 625 nm. The photocatalytic activity of V-doped TiO2 powders were evaluated by the photocatalytic degradation of methyl orange （MO） under visible light irradiation. It is found that V doping enhances the photoeatalyilc activity under visible light irradiation and the optimal degradation rate of MO is about 95.8% with 1.0 at% V-doped TiO2.

Enhanced photocatalytic activity of (La, N) co-doped TiO_2 by TiCl_4 sol-gel autoigniting synthesis

（La, N） co-doped TiO2 photocatalysts were synthesized using TiC14 sol-gel autoignidng synthesis （SAS） starting from a complex compound system of TiCl4-La（NO3）3-citric acid-NH4NO3-NHyH2O, in which the （La, N） co-doped process was accompushed in the formation of TiO2 nanocrystals. The prepared samples were characterized by using X-ray diffraction （XRD）, X-ray photoemission spectroscopy （XPS） and UV-vis diffuse reflectance spectra. The results indicated that nitrogen and lanthanum were incorporated into the lattice and interstices of titania nanocrystals, which resulted in narrowing the band gap and promoting the separation of photoexcited hole-electron pairs, respectively, and showing expected red-shifts and enhanced photocatalytic activity under visible light. The mechanism on nitrogen doping and enhancement in photocatalyfic activity of （La, N） co-doped titania by SAS was discussed in detail.

Preparation and characterization of in-site regenerated TiO_2-ACFs photocatalyst

In-site regenerated titanium dioxide-activated carbon fibers （TiO2-ACFs） photocatalyst was prepared by the sol-gel method. De-tailed surface and structural characterization of the TiO2-ACFs photocatalyst was carried out. The photoactivity of TiO2-ACFs under ultra-violet irradiation was compared with original ACFs and pure TiO2 by the degradation of methylene blue aqueous solution. The degradation efficiency by the TiO2 （5wt%）-ACFs sample is much higher than that by TiO2 and ACFs. The results show that the photocatalysis by TiO2-ACFs is a six-step process. The adsorption-transfer-photocatalysis rate of TiO2-ACFs is higher than the adsorption-photocatalysis rate of TiO2, so the photocatalysis rate of the TiO2-ACFs system is higher than that of TiO2 photocatalyst.

Carbon coated ultrasmall anatase TiO_2 nanocrystal anchored on N,S-RGO as high-performance anode for sodium ion batteries

Anatase TiO_2 has been investigated as one of the most promising anode materials for sodium ion batteries(SIBs)with low cost and high theoretical capacity.Herein,a composite material of TiO_2 /N,S-RGO@C with carbon coated ultrasmall anatase TiO_2 anchored on nitrogen and sulfur co-doped RGO matrix was successfully prepared by a rational designed process.The composite structure exhibited ultrasmall crystal size,rich porous structure,homogeneous heteroatoms doping and thin carbon coating,which synergistically resulted in elevated electron and ion transfer.The anode exhibited high rate capacities with good reversibility under high rate cycling.The carbon coating was investigated to be effective to prevent active material falling and lead to long term cycling performance with a high capacity retention of 181 m Ah g^(à1)after 2000cycles at 2 C.Kinetic studies were carried out and the results revealed that the superior performance of the composite material were derived from the decreased charge transfer resistance and elevated ion diffusion.Results suggested that the TiO_2 /N,S-RGO@C composite is a promising anode material for sodium ion batteries.

纳米二氧化钛复合材料降解水中污染物的研究

对金属离子掺杂纳米二氧化钛复合光催化材料降低水中污染物的研究进展进行了论述;金属离子掺杂纳米二氧化钛复合光催化材料相较于纳米二氧化钛,其禁带宽度变窄,提高了在可见光区的吸收性能,提高了光催化活性,提高了污染物降解率。

非金属离子掺杂纳米二氧化钛复合光催化材料降低水中污染物的研究进展

对非金属离子掺杂纳米二氧化钛复合光催化材料降低水中污染物的研究进展进行论述;非金属离子掺杂纳米二氧化钛复合光催化材料相较于纳米二氧化钛,其禁带宽度变窄,提高了在可见光区的吸收性能,提高了光催化活性,提高了污染物降解率。

C@TiCoO_(3)@TiO_(2)纳米材料制备及在可见光下的抗菌性

研究通过溶胶-凝胶法,将钴元素(Co)与TiO_(2)掺杂在一起合成C@TiCoO_(3)@TiO_(2)纳米材料,并用扫描电子显微镜(SEM)、X射线衍射光谱(XRD)、X射线光电子能谱(XPS)和紫外-可见漫反射测试(UV-Vis DRS)对其进行表征。结果表明:该材料由Ti、O、C、Co元素组成,呈块状;主要以锐钛矿晶型形式存在,可见光的吸收范围大(762 nm),禁带宽度窄(1.63 eV),对可见光有较好的响应能力。5 mg/mL的C@TiCoO_(3)@TiO_(2)在LED可见光(功率7 W)下,分别照射60和100 min即可完全杀灭金黄色葡萄球菌和大肠埃希菌。细胞毒性实验表明,合成的C@TiCoO_(3)@TiO_(2)具有较好的生物相容性。实验合成的C@TiCoO_(3)@TiO_(2)纳米复合材料有潜在的抗菌应用价值。

Influence of V^(5+) Ions on Photocatalytic Activity of TiO_2 Films Prepared by Micro-plasma Oxidation Method

Microporous titanium dioxide thin films have been fabricated on titanium plates by the micro-plasma oxidation method with the electrolyte of Na3PO4+Na2B4O7. The influence of V5+ ions addition in the electrolyte on the photocatalytic activities was investigated. A kind of typical textile industry pollutant (methylene blue) was used to evaluate the photo-catalytic activity of the films. The results showed that this activity of the films had been improved by adding V5+ ions into the electrolyte solution. The removal of methylene blue reaches 90% for 60 min when V5+ ions addition concentrate is 0.3 g/L. X-ray diffraction, scanning electron microscopy and atomic force microscopy techniques were applied to characterize the modified films. Experimental results show that the improvement in activity was related to the forming of titanium dioxide lattice distortion, which could accept more photoexcitated holes and produce more strong surface free radicals to oxidate adsorptive molecules.

石墨烯复合金属离子掺杂纳米二氧化钛光催化材料的研究进展

对石墨烯复合金属离子掺杂纳米二氧化钛光催化材料在污染物治理、CO_(2)还原和资源化、H_(2)生产等方面的研究进展进行了论述。石墨烯复合金属离子掺杂纳米二氧化钛光催化材料相较于纳米二氧化钛,其禁带宽度变窄,提高了在可见光区的吸收性能,提高了光催化活性,提高了污染物降解率、CO_(2)还原和资源化的产率和H_(2)生产效率。