Enhancement of solar light photocatalytic activity of TiO2-CeO2 composite by Er3+:Y3Al5O12 in organic dye degradation

The Er³⁺:Y₃Al₅O₁₂, as an upconversion luminescence agent which is able to transform the visible part of the solar light to ultraviolet light, was prepared by nitrate-citrate sol-gel method. A novel solar light photocatalyst, Er³⁺:Y₃Al₅O₁₂/TiO₂-CeO₂ composite was synthesized using ultrasonic treatment. The X-ray diffraction (XRD) and scanning election microscopy (SEM) were used to characterize the structural morphology of the Er³⁺:Y₃Al₅O₁₂/TiO₂-CeO₂ composite. In order to evaluate the solar light photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/TiO₂-CeO₂ composite, the Azo Fuchsine dye was used as a model organic pollutant. The progress of the degradation reaction was monitored by UV-Vis spectroscopy and ion chromatography. The key influences on the solar light photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/TiO₂-CeO₂ were studied, such as Ti/Ce molar ratio, heat-treatment temperature and heat-treatment time. Otherwise, the effects of initial dye concentration, Er³⁺:Y₃Al₅O₁₂/TiO₂-CeO₂ amount, solar light irradiation time and the nature of the dye on the solar light photocatalytic degradation process were investigated. It was found that the solar light photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/TiO₂-CeO₂ composite was superior to Er³⁺:Y₃Al₅O₁₂/TiO₂ and Er³⁺:Y₃Al₅O₁₂/CeO₂ powder in the similar conditions.     

Application of TiO2/Er3+:Y3Al5O12 composite to photo-degrade acid red B dye under sun light irradiation

In this work, an upconversion luminescence agent, Er³⁺:Y₃Al₅O₁₂, was synthesized and its absorption and fluorescent spectra was determined. By calculation, the upconversion efficiency of the emission peak at 320 nm was estimated to be about 3.4%. And then, TiO₂/Er³⁺:Y₃Al₅O¹² composite was prepared by simple ultrasonic dispersion and liquids boil methods. The obtained composite was characterized by X-ray diffrac-tion. The effect of TiO₂/Er³⁺:Y₃Al₅O₁₂ composite with different Er³⁺:Y₃Al₅O₁₂ doping amount, heat-treated temperature and heat-treated time on photodegradation of acid red B under sun light was investigated in detail. It was found that the photocatalytic activity of TiO₂/Er³⁺:Y₃Al₅O₁₂ composite was much higher than that for the similar system with only TiO₂ powder. These results support the usefulness of TiO₂/Er³⁺:Y₃Al₅O₁₂ composite in the process of photodegrading dye wastewater and using the sun light.     

The improvement of solar photocatalytic activity of ZnO by doping with Er3+:Y3Al5O12 during dye degradation

The Er³⁺:Y₃Al₅O₁₂, an upconversion luminescence agent, which is able to transform the visible light to ultraviolet light, was synthesized by nitrate-citric acid method. And then, a novel photocatalyst, Er³⁺:Y₃Al₅O₁₂/ZnO composites, was prepared by ultrasonic dispersing and liquid boil method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the structural morphology and surface properties of the Er³⁺:Y₃Al₅O₁₂/ZnO. Azo Fuchsine dye was selected as target organic pollutant to inspect the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/ZnO. The key parameters affecting the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/ZnO, such as Er³⁺:Y₃Al₅O₁₂ content, heat-treatment temperature and heat-treatment time, were studied. In addition, the effects of dye initial concentration, Er³⁺:Y₃Al₅O₁₂/ZnO amount and solar light irradiation time were also reviewed, as well as the photocatalytic activity in degradation of other organic dyes were compared. It was found that the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/ZnO was much superior to pure ZnO under the same conditions. Thus, the Er³⁺:Y₃Al₅O₁₂/ZnO is a useful photocatalyst for the wastewater treatment because it can efficiently utilize solar light by converting visible light into ultraviolet light.     

Synthesis of Er3+:Y3Al5O12 and its effects on the solar light photocatalytic activity of TiO2–ZrO2 composite

The Er³⁺:Y₃Al₅O₁₂ as an upconversion luminescence agent, which can transform visible light into ultraviolet light, was synthesized by nitrate?Ccitrate acid and calcined method. Then, a novel photocatalyst, Er³⁺:Y₃Al₅O₁₂/TiO₂?CZrO₂, was prepared using ultrasonic dispersion and liquid boiling method. The samples were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). In succession, the degradation process of organic dye was monitored by UV?CVis spectrum and ion chromatography for verifying the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/TiO₂?CZrO₂. The influences on its photocatalytic activity such as Ti/Zr molar ratio, heat-treated temperature, and time were studied. In addition, the influences of initial concentration, Er³⁺:Y₃Al₅O₁₂/TiO₂?CZrO₂ amount, solar light irradiation time, and organic dye category on the photocatalytic degradation efficiency were also investigated. It was found the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/TiO₂?CZrO₂ was superior to Er³⁺:Y₃Al₅O₁₂/TiO₂ and Er³⁺:Y₃Al₅O₁₂/ZrO₂. Therefore, the Er³⁺:Y₃Al₅O₁₂/TiO₂?CZrO₂ is a useful photocatalytic material for the wastewater treatment duo to efficient utilization of solar light.     

The influence of Yb, B, and Ga-doped Er3+:Y3Al5O12 on solar light photocatalytic activity of TiO2 in degradation of organic dyes

Five up-conversion luminescence agents (Er³⁺:Y₃Al₅O₁₂, Er³⁺:Yb _n Y_{3 ? n} Al₅O₁₂, Er³⁺:Y₃B _a Al_{5 ? a} O₁₂, Er³⁺:Y₃Ga _b Al_{5 ? b} O₁₂, and Er³⁺:Yb _n Y_{3 ? n} B _a Ga _b Al_{5 ? a ? b} O₁₂) were synthesized using sol-gel method and then the corresponding coated composites (Er³⁺:Y₃Al₅O₁₂/TiO₂, Er³⁺:Yb _n Y_3?n Al₅O₁₂/TiO₂, Er³⁺:Y₃B _a Al_{5 ? a} O₁₂/TiO₂, Er³⁺:Y₃Ga _b Al_{5 ? b} O₁₂/TiO₂, and Er³⁺:Yb _n Y_{3 ? n} B _a Ga _b Al_{5 ? a ? b} O₁₂/TiO₂) as photocatalysts were prepared by sol-gel coating process. The XRD and SEM were used to confirm the crystalline phase and surface morphology. The UV-vis absorption and fluorescence-emission spectra were used to research the effect of doping category and amount on the up-conversion emission ability. The photocatalytic activities were detected through the degradation of Acid Red B dye in aqueous solution. Some key parameters of catalyst amount and initial concentration of organic dye on solar light photocatalytic degradation were also examined. The extensive feasibility of prepared photocatalysts in solar light degradation was detected by other organic dyes. The results suggest that the photocatalysts can be widely used in sewage treatment.     

High photocatalytic activity and stability for decomposition of gaseous acetaldehyde on TiO2/Al2O3 composite films coated on foam nickel substrates by sol-gel processes

A set of anatase titanium dioxide (TiO₂) films coated on foam nickel that modified by Al₂O₃ films as transition layer (indicated as TiO₂/Al₂O₃ films) were synthesized via sol-gel route. The bulk and surface properties of the TiO₂/Al₂O₃ films were characterized by thermal gravimetric and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and BET. The photocatalytic activities of TiO₂/Al₂O₃ films were investigated based on the degradation of gaseous acetaldehyde under ultraviolet (UV) irradiation. The foam nickel is a promising substrate material in practical applications because of its excellent hydrodynamic properties for gas passing. The TiO₂/Al₂O₃ composite films showed much higher photocatalytic activity and stability for degradation of gaseous acetaldehyde than the onefold TiO₂ films. The significant enhancement in photocatalytic activity and stability can be ascribed to the coating of Al₂O₃ transition layer, which concentrates the target substances around TiO₂ particles and increases the specific surface area (SSA) of the substrate (the SSAs of bare foam nickel and Al₂O₃ modified foam nickel are 0.12 and 113.7 m²/g, respectively) to provide more sites for TiO₂ loading.     

Er~(3+)∶V_(0.01)Y_(2.99)Al_5N_(0.01)F_(0.01)O_(11.98)/BiPO_4/Pt光催化剂的制备及其在降解废水中亚甲基蓝的应用

通过溶胶-凝胶法合成了上转换发光材料Er~(3+)∶V_(0.01)Y_(2.99)Al_5N_(0.01)F_(0.01)O_(11.98)(Er∶YAG),然后利用水热法合成了BiPO_4,再利用高温煅烧法合成了Er∶YAG/BiPO_4/Pt复合物光催化剂.通过使用X-射线粉末衍射仪(XRD),扫描电子显微镜(SEM),透射电子显微镜(TEM),光致发光光谱(PL)和上转换发射光谱对样品的组成、形貌及光学特征进行了表征.此外,还研究了不同甘油添加量、 Er∶YAG和BiPO_4的摩尔比例和复合温度及光催化剂的循环使用次数对Er∶YAG/BiPO_4/Pt复合物光催化剂活性的影响.实验结果显示Er∶YAG/BiPO_4/Pt复合物光催化剂具有高的光催化活性和较好的稳定性,它可以作为一种高效的光催化剂用于污水中有机污染物的处理.     

Preparation of Er3+:YAlO3/Fe-doped ZnO composite and investigation on solar light photocatalytic degradation of organic dyes

The Er³⁺:YAlO₃/Fe-doped ZnO composite, a new photocatalyst which could effectively utilize visible light, was prepared. In succession, the Er³⁺:YAlO₃/Fe-doped ZnO was characterized by XRD and SEM, respectively. Acid Red B dyes, was degraded under solar light irradiation to evaluate the photocatalytic activity of the Er³⁺:YAlO₃/Fe-doped ZnO. In addition, the effects of Er³⁺:YAlO₃ content, heat-treatment temperature and time on the photocatalytic activity of Er³⁺:YAlO₃/Fe-doped ZnO were reviewed. Otherwise, the effect of initial dye concentration, Er³⁺:YAlO₃/Fe-doped ZnO amount and solar light irradiation time on the photocatalytic degradation of Acid Red B were also investigated. It was found that the photocatalytic activity of Er³⁺:YAlO₃/Fe-doped ZnO is much higher than that of Fe-doped ZnO and pure ZnO for the similar system. Perhaps, the use of the Er³⁺:YAlO₃/Fe-doped ZnO may provide a new way to take advantage of ZnO in sewage treatment aspects using solar energy.     

Effects of nano-YAG (Y3Al5O12) crystallization on the structure and photoluminescence properties of Nd3+-doped K2O–SiO2–Y2O3–Al2O3 glasses

Nd³⁺-doped precursor glass in the K₂O–SiO₂–Y₂O₃–Al₂O₃ (KSYA) system was prepared by the melt-quench technique. The transparent Y₃Al₅O₁₂ (YAG) glass–ceramics were derived from this glass by a controlled crystallization process at 750 °C for 5–100 h. The formation of YAG crystal phase, size and morphology with progress of heat-treatment was examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transformed infrared reflectance spectroscopy (FT-IRRS). The crystallite sizes obtained from XRD are found to increase with heat-treatment time and vary in the range 25–40 nm. The measured photoluminescence spectra have exhibited emission transitions of ⁴F_3/2 → ⁴I_J (J = 9/2, 11/2 and 13/2) from Nd³⁺ ions upon excitation at 829 nm. It is observed that the photoluminescence intensity and excited state lifetime of Nd³⁺ ions decrease with increase in heat-treatment time. The present study indicates that the incorporation of Nd³⁺ ions into YAG crystal lattice enhance the fluorescence performance of the glass–ceramic nanocomposites.     

Photocatalysis enhancement of CaAl<Subscript>2</Subscript>O<Subscript>4</Subscript>:Eu<Superscript>2+</Superscript>, Nd<Superscript>3+</Superscript>@TiO<Subscript>2</Subscript> composite powders

CaAl₂O₄:Eu²⁺, Nd³⁺@TiO₂ composite powders were synthesized by a sol–gel method under mild conditions (i.e. low temperature and ambient pressure). The as-prepared powders were characterized by transmission electron microscopy (TEM) and analyzed by X-ray diffraction (XRD). The photocatalytic behavior of the TiO₂-base surfaces was evaluated by the degradation of nitrogen monoxide gas. It suggested that CaAl₂O₄:Eu²⁺, Nd³⁺@TiO₂ composite powders were composed of anatase titania and that CaAl₂O₄:Eu²⁺, Nd³⁺. TiO₂ particles were deposited on the surface of CaAl₂O₄:Eu²⁺, Nd³⁺ to form uniform film. CaAl₂O₄:Eu²⁺, Nd³⁺@TiO₂ composite powders exhibited higher photocatalytic activity compared with pure TiO₂ under visible light. And the result also clearly indicated that the long afterglow phosphor absorbed and stored lights for the TiO₂ to remain photocatalytic activity in the dark.     

Investigation of the homogeneity of the distribution of doped elements in oxide single crystals

Summary The homogeneity of the distributions of doped V and Ti in Al₂O₃:V³⁺, Y₃Al₅O₁₂:V³⁺, Al₂O₃:Ti³⁺, Y₃Al₅O₁₂:Ti³⁺ single crystals was studied by means of laser emission microanalysis. The applied statistical methods include one-way variance analysis, two-way variance analysis, regression models and the gradient method.     

Fabrication and electron transport properties of epitaxial films of electron-doped 12CaO·7Al2O3 and 12SrO·7Al2O3

Epitaxial growth and electron doping of 12CaO·7Al₂O₃ (C12A7) and 12SrO·7Al₂O₃ (S12A7) are reported. The C12A7 films were prepared on Y₃Al₅O₁₂ (YAG) single-crystal substrates by pulsed laser deposition at room temperature and subsequent thermal crystallization. X-ray diffraction patterns revealed the films were grown epitaxially with the orientation relationship of (001)[100] C12A7 || (001)[100] YAG. For S12A7, pseudo-homoepitaxial growth was attained on the C12A7 epitaxial layer. Upon electron doping, metallic conduction was achieved in the C12A7 film and the S12A7/C12A7 double-layered films. Analyses of optical absorption spectra for the S12A7/C12A7 films provided the densities of free electrons in each layer separately. Hall measurements exhibited larger electron mobility in the S12A7/C12A7 film than those in C12A7 and S12A7 films, suggesting free electrons may be accumulated at the S12A7/C12A7 interface due presumably to a discontinuity of the cage conduction bands.     

掺杂钒和硅对TiO2薄膜超亲水性的影响

0引言 TiO2薄膜是众多氧化物半导体薄膜中研究最为广泛的一种材料．其表面的超亲水性和表面自清洁效应开辟了光催化薄膜功能材料的新的研究领域，已成为众多研究者研究的对象。但是如果薄膜仅由TiO2组成，当光照停止，水在TiO2薄膜表面的润湿角逐渐升高．并恢复原始状态。TiO2的禁带较宽，普通光线如太阳光等都不能将其激发．限制了其实际应用。因此如何使TiO2材料的光谱响应范围由紫外光反扩展到可见．光区一日如何更长时间地保持薄膜良好的亲水性是目前研究的重点。     

Photoluminescence and photocatalytic properties of Er<Superscript>3+</Superscript>-doped In<Subscript>2</Subscript>O<Subscript>3</Subscript> thin films prepared by sol–gel: application to Rhodamine B degradation under solar light

The effect of Er³⁺ doping (1%) on the structural, optical and photocatalytic properties of In₂O₃ thin films deposited on quartz substrates by spin coating was investigated. The In₂O₃:1% Er³⁺ films, annealed in the temperature range 800–1000 °C, were characterized by X-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy, UV–Vis spectroscopy, ellipsometry and photoluminescence (PL). The films are polycrystalline with a cubic structure and the lattice parameter increases with the incorporation of Er³⁺ owing to its larger radius. The SEM images of the film show a granular morphology with large grains (~ 200 nm). The doped In₂O₃ film exhibits less transparency than In₂O₃ in the UV–visible region with band gaps of 3.42 and 3.60 eV, respectively. PL shows strong lines at 548 and 567 nm, assigned to Er³⁺ under direct excitation at 532 nm. The energy diagram of the junction In₂O₃:1% Er³⁺/Na₂SO₄ (0.1 M) solution plotted from physical and photoelectrochemical characterizations shows the feasibility of the films for Rhodamine B (RhB) degradation under solar light. The conduction band at 2.22 V deriving from the In³⁺:5s orbital is suitably positioned with respect to the O₂/O ₂ ^· level (~ 1.40 V_SCE), leading to oxidation of 32% of 10 ppm RhB within 40 min of solar irradiation.     

Formation of Superhydrophobic-Superhydrophilic Pattern on Flowerlike Alumina Thin Film by the Sol-Gel Method

We have prepared superhydrophobic surfaces which become superhydrophilic by heat-treatment at 500°C or irradiation of UV-light. When hydrolyzed fluoroalkyltrimethoxysilane (FAS) was coated on Al₂O₃ gel film with a roughness of 20 to 50 nm, the films showed superhydrophobicity and high transparency; the contact angle for water of the film was 165° and the transmittance for the visible light was higher than 92%. When the FAS-coated thin films were heat-treated at temperatures higher than 500°C, the films became superhydrophilic; the contact angle for water on the films was smaller than 5°. Thin films of amorphous TiO₂ or anatase TiO₂ were coated between Al₂O₃ gel and FAS layer, and the contact angle for water was also about 160°. UV irradiation using high-pressure mercury lamp on these films resulted in the contact angle to be smaller than 5°. When UV light was irradiated through a photomask, superhydrophobic-superhydrophilic micropatterns applicable as a stamper for printing or a substrate of micro-optical components were successfully obtained on the films.     

The influence of polyvinylpyrrolidone on thick and optical properties of BaTiO<Subscript>3</Subscript>:Er<Superscript>3+</Superscript> thin films prepared by sol–gel method

Erbium (Er³⁺) 0.5% mol doped barium titanate (BaTiO₃) thin films were elaborated via sol–gel method and dip-coating technique using titanium alkoxide and barium pentanedionate. Two syntheses were performed [with and without polyvinylpyrrolidone (PVP)] in order to obtain thick films. The BaTiO₃:Er³⁺ thin films prepared from the sol with PVP were elaborated with 1 layer and those without PVP and were elaborated with 17 layers. In both cases, the films were deposited on silica quartz substrates. Both BaTiO₃:Er³⁺ films presented a cubic phase, as determined by X-ray diffraction. BaTiO₃:Er³⁺ films elaborated with PVP via single-step dip coating produced crack-free films with thicknesses of ~800 nm. SEM micrographs for the obtained BaTiO₃:Er³⁺ films revealed high homogeneity and density. Mapping images obtained from BaTiO₃:Er³⁺ revealed homogeneous distribution of Er³⁺ ions on the surface. XPS analyses of the chemical state and chemical environment of the constituent elements in the compositions showed that Er³⁺ ions in (Ba_1−x Er _x )TiO₃ are in mixed valence of Er³⁺/Er²⁺. The BaTiO₃:Er³⁺-PVP film exhibited luminescent properties under near-infrared excitation, as revealed by green emissions. The BaTiO₃:Er³⁺-PVP film has good potential for optical applications.     

Photocatalytic degradation of organic dyes by Er<Superscript>3+</Superscript>: YAlO<Subscript>3</Subscript>/Co- and Fe-doped ZnO coated composites under solar irradiation

In this work, the Er³⁺: YAlO₃/Co- and Fe-doped ZnO coated composites were prepared by the sol-gel method. Then, they were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). Photo-degradation of azo fuchsine (AF) as a model dye under solar light irradiation was studied to evaluate the photocatalytic activity of the Er³⁺: YAlO₃/Co- and Fe-doped ZnO coated composites. It was found that the photocatalytic activity of Co- and Fe-doped ZnO composites can be obviously enhanced by upconversion luminescence agent (Er³⁺: YAlO₃). Besides, the photocatalytic activity of Er³⁺: YAlO₃/Fe-doped ZnO is better than that of Er³⁺: YAlO₃/Co-doped ZnO. The influence of experiment conditions, such as the concentration of Er³⁺: YAlO₃, heat-treatment temperature and time on the photocatalytic activity of the Er³⁺: YAlO₃/Co- and Fe-doped ZnO coated composites was studied. In addition, the effects of solar light irradiation time, dye initial concentration, Er³⁺: YAlO₃/Co- and Fe-doped ZnO amount on the photocatalytic degradation of azo fuchsine in aqueous solution were investigated in detail. Simultaneously, some other organic dyes, such as Methyl Orange (MO), Rhodamine B (RM-B), Acid Red B (AR-B), Congo Red (CR), and Methyl Blue (MB) were also studied. The possible excitation principle of Er³⁺: YAlO₃/Co- and Fe-doped ZnO coated composites under solar light irradiation and the photocatalytic degradation mechanism of organic dyes were discussed.     

Gd2O3:Er3+上转换发光粉在染料敏化太阳电池中的应用

采用沉淀-煅烧法制备了Gd₂O₃:Er³⁺上转换发光粉,通过X射线衍射、扫描电子显微镜、能谱和荧光光谱对其进行了表征,并利用该发光粉具有上转换发光的特性将其应用于染料敏化太阳电池(DSSC)。结果表明,管状Gd₂O₃:Er³⁺上转换发光粉可增加电池对太阳光的吸收范围和吸收效率,提高电池的光电流和光电压。研究了掺杂量对电池性能的影响,当掺杂量为5wt%时,光电转换效率从5.93%升高到7.55%,提高约27%。     

Eliminated Phototoxicity of TiO2 Particles by an Atomic‐Layer‐Deposited Al2O3 Coating Layer for UV‐Protection Applications

We demonstrate the conformal coating of an ultrathin Al₂O₃ layer on TiO₂ nanoparticles through atomic layer deposition by using a specifically designed rotary reactor to eliminate the phototoxicity of the particles for cosmetic use. The ALD reactor is modified to improve the coating efficiency as well as the agitation of the particles for conformal coating. Elemental and microstructural analyses show that ultrathin Al₂O₃ layers are conformally deposited on the TiO₂ nanoparticles with a controlled thickness. Rhodamine B dye molecules on Al₂O₃‐coated TiO₂ exhibited a long life time under UV irradiation, that is, more than 2 h, compared to that on bare TiO₂, that is, 8 min, indicating mitigation of photocatalytic activity by the coated layer. The effect of carbon impurities in the film resulting from various deposition temperatures and thicknesses of the Al₂O₃ layer on the photocatalytic activity are also thoroughly investigated with controlled experimental condition by using dye molecules on the surface. Our results reveal that an increased carbon impurity resulting from a low processing temperature provides a charge conduction path and generates reactive oxygen species causing the degradation of dye molecule. A thin coated layer, that is, less than 3 nm, also induced the tunneling of electrons and holes to the surface, hence oxidizing dye molecules. Furthermore, the introduction of an Al₂O₃ layer on TiO₂ improves the light trapping thus, enhances the UV absorption.     

Synthesis and photoluminescence of the Y2O3:Eu3+ phosphor nanowires in AAO template

The monodisperse array and nanowires of Y₂O₃:Eu³⁺ phosphor were synthesized using anodic aluminum oxide (AAO) template by sol–gel method. Scanning electron microscope (SEM) images indicated that Y₂O₃:Eu³⁺ nanowires are parallelly arranged, all of which are in uniform diameter of about 50 nm. The high-magnification SEM image showed that each nanowire is composed of a lot of agglutinating particles. The patterns of selected-area electron diffraction confirmed that Y₂O₃:Eu³⁺ nanowires mainly consist of polycrystalline materials. Excitation and emission spectra of Y₂O₃:Eu³⁺/AAO composite films were measured. The characteristic red emission peak of Eu³⁺ ion attributed to ⁵D₀→⁷F₂ transition in Y₂O₃:Eu³⁺/AAO nanowires broadened its halfwidth.