MgAl2O4:Mg荧光粉的合成及其发光性能
Fabrication and Photoluminescence Properties of MgAl2O4: Mg Phosphors
通讯作者: 王仕发,副教授,20180011@sanxiau.edu.cn,研究方向为光电子信息与智能材料
责任编辑: 吴岩
收稿日期: 2020-03-09 修回日期: 2020-04-27 网络出版日期: 2020-10-25
基金资助: |
|
Corresponding authors: WANG Shifa, Tel: 15826383083, E-mail:20180011@sanxiau.edu.cn
Received: 2020-03-09 Revised: 2020-04-27 Online: 2020-10-25
Fund supported: |
|
作者简介 About authors
刘欣怡,女,1998年生,本科生
用超声辅助聚丙烯酰胺凝胶法合成了MgAl2O4:Mg荧光粉。在MgAl2O4体系中引入的Mg金属颗粒抑制了MgAl2O4相的形成,在900℃及以上的温度烧结MgAl2O4:Mg干凝胶粉末,镁颗粒氧化成MgO。Mg金属颗粒的引入使MgAl2O4:Mg荧光粉的形貌由细小的纳米颗粒变为方便面型;MgAl2O4:Mg荧光粉的颜色由在600℃烧结时的暗棕色变为在800℃烧结时的白色,在1000℃烧结时白色变暗。随着烧结温度的提高MgAl2O4:Mg荧光粉的能带先增大后略微减小。引入镁颗粒使荧光光谱中位于395和425 nm的两个荧光峰淬灭,在650、656和680 nm出现三个新的荧光发射峰,且随着烧结温度的提高发光强度减弱。金属颗粒的表面等离子体共振导致MgAl2O4主晶格荧光淬灭,缺陷能级使MgAl2O4:Mg荧光粉产生了新的荧光发射峰。
关键词:
A novel MgAl2O4:Mg phosphor was prepared by ultrasonic assisted polyacrylamide gel method. When Mg metal particles were introduced into the MgAl2O4 system, the formation of MgAl2O4 phase was inhibited. When the xerogel powder MgAl2O4:Mg was sintered at 900℃ or above, the incorporated Mg-particles are oxidized to be MgO. The introduction of Mg-particles greatly changed the morphology of MgAl2O4:Mg phosphors, namely from tiny nanoparticles to instant noodles-like. The results show that the sintering temperature has great influence on the color, light absorption capacity, energy band Eg and photoluminescence properties of MgAl2O4:Mg phosphors. The color of MgAl2O4:Mg phosphors changes from dark brown for sintering at 600℃ to bright white at 800℃ and then to light white at 1000℃. With the increase of sintering temperature the Eg value of MgAl2O4:Mg phosphors increased first and then decreased slightly. The photoluminescence spectra show that three new photoluminescence emission peaks located at 650, 656 and 680 nm are observed when the excitation wavelength is 325 nm. The photoluminescence intensity decreased with the increasing of sintering temperature. The fluorescence emission peaks at 395 and 425 nm of host lattice MgAl2O4 were quenched. The surface plasmon resonance (SPR) of Mg metal particles led to the fluorescence quenching of MgAl2O4 host lattice, and the defect energy level can produce a new fluorescence emission band at 635~690 nm of MgAl2O4:Mg phosphors.
Keywords:
本文引用格式
刘欣怡, 王仕发, 余先伦, 唐盛楠, 房雷鸣, 雷力.
LIU Xinyi, WANG Shifa, YU Xianlun, TANG Shengnan, FANG Leiming, LEI Li.
目前,提高MgAl2O4发光性能的方法主要有三种。一是引入金属氧化物构成特殊的能级结构以提高电子空穴对的复合几率,从而改善MgAl2O4的发光性能[5,9];二是引入合适的激活离子如稀土元素、Fe、Co、Ni、Mn、C、N等,或基于能量传递原理同时引入多种离子增强的MgAl2O4的发光性能[5,10,11];三是用离子辐照引入缺陷,改善MgAl2O4的发光性能[12,13]。近年来,发展了一种用金属颗粒与半导体氧化物复合增强主晶格材料发光或其它物理化学性能的新方法[14~17]。本文用微波辅助聚丙烯酰胺凝胶法合成 MgAl2O4:Mg荧光粉,研究烧结温度对MgAl2O4:Mg荧光粉相结构、官能团、颜色、光吸收能力、能带值及发光性能的影响,并基于能带理论研究在MgAl2O4中引入镁颗粒后主晶格材料荧光的淬灭和出现新荧光发射峰的机理。
1 实验方法
1.1 材料的合成
将适量的镁粉加入20 mL的去离子水中,在室温超声30 min后得到A溶液。将适量的三氯化铝和硝酸镁依次添加到装有20 mL去离子水的烧杯中,超声30 min后得到B溶液。将B溶液倒入装有A溶液的烧杯中,在持续超声条件下逐次加入4.7282 g柠檬酸、20 g葡萄糖、9.5958 g丙烯酰胺和1.9192 g亚甲基双丙烯酰胺。上述溶液混合均匀后烧杯转移到带升温装置的搅拌器上进行升温,在80℃持续搅拌以使丙烯酰胺和亚甲基双丙烯酰胺聚合,得到果冻状凝胶。将果冻状凝胶转移至120℃干燥箱中干燥24 h,得到黑色干凝胶。将干凝胶研磨成粉。将部分粉末分别在600、700、800、900和1000℃烧结5 h,得到目标产物-MgAl2O4:Mg荧光粉。MgAl2O4与Mg粉的质量比为9:1。MgAl2O4:Mg荧光粉的制备流程,如图1所示。
图1
图1
MgAl2O4:Mg荧光粉的制备流程
Fig.1
Chemical route for the preparation of MgAl2O4:Mg phosphors.
1.2 材料的表征
使用DX-2700型X射线粉末衍射仪分析MgAl2O4:Mg荧光粉的相结构和纯度,测试波长为0.15406 nm,操作电流为30 mA,操作电压为40 kV。使用IFS 66 v/S型傅里叶红外光谱以测量MgAl2O4:Mg荧光粉的红外光谱,测试波数范围为400~4000 cm-1。用ULTRA 55型场发射扫描电镜表征MgAl2O4:Mg荧光粉的表面形貌。使用紫外可见分光光度计在积分球附件上测量MgAl2O4:Mg荧光粉的紫外可见漫反射光谱。使用He-Cd激光器在共聚焦拉曼光谱系统上室温采集MgAl2O4:Mg荧光粉的的荧光光谱,激发波长为325 nm。采用He-Cd激光器(325 nm)作为激发光源,在室温测量了MgAl2O4:Mg干凝胶粉末在不同温度烧结产物的荧光光谱。
2 结果和讨论
2.1 XRD分析
金属颗粒和烧结温度对MgAl2O4的相纯度有较大影响。将MgAl2O4:Mg干凝胶粉末在不同温度烧结,其产物的XRD图谱如图2所示。由图2可知,在600℃煅烧MgAl2O4:Mg干凝胶粉末,得到的样品为非晶态,与在600℃煅烧MgAl2O4干凝胶粉体得到的产物结果一致[7]。将MgAl2O4:Mg干凝胶粉末在700℃烧结,开始出现立方相的MgAl2O4的衍射峰,标准JCPDS卡片号为21-1152。衍射角在31.265、36.851、44.829、55.655、59.370、65.239和78.401o对应的晶面指数分别为(220)、(311)、(400)、(422)、(511)、(440)和(622)。随着烧结温度的提高,衍射峰的强度逐渐增强。烧结温度达到900℃时出现MgO的衍射峰,标准JCPDS卡片号为30-0794。烧结温度为1000℃时MgAl2O4和MgO(□)的衍射峰被进一步增强。由此可见,当烧结温度达到900℃或以上时,镁金属颗粒容易氧化为MgO。在低温烧结过程中未观察到Mg金属颗粒的衍射峰,其主要原因:一是Mg金属颗粒的含量不高,Mg金属颗粒很容易被包覆在厚厚的MgAl2O4前驱体壳层内,测量时X射线穿透深度不一定能达到可测范围;但是,随着烧结温度的提高MgAl2O4的结晶度提高,其它有机物杂质减少,甚至Mg金属颗粒出现氧化;二是Mg金属颗粒的主峰集中在2θ=32.193°和36.619°,这些衍射峰几乎与MgAl2O4的衍射峰重合,导致未观察到Mg金属颗粒的衍射峰。从图2还可以看出,金属颗粒和烧结温度没有改变MgAl2O4主晶格相的晶体结构。
图2
图2
MgAl2O4:Mg干凝胶粉末在不同温度烧结后的产物和MgAl2O4的XRD图谱
Fig.2
XRD patterns of MgAl2O4:Mg xerogel powders calcined at different temperatures
2.2 红外光谱分析
红外光谱是分析样品中官能团的有效手段。图3给出了MgAl2O4:Mg干凝胶粉末在不同温度烧结产物的FTIR图谱。由图3可见,所有样品均出现了1640和3441 cm-1的吸收峰,且随着烧结温度的提高吸收峰的强度逐渐减弱。根据文献[18~20],1640和3441 cm-1的吸收峰可分别归因于吸附水的弯曲和伸缩振动模式。MgAl2O4:Mg干凝胶粉末在600~800℃的烧结产物,有两个有机物的吸收峰。位于2925和2834 cm-1的两个吸收峰,可分别归因于-CH在-CH和-CH2的伸缩振动和碳酸根离子[21,22]。此外,一个位于1431 cm-1的碳酸根离子吸收峰直到烧结温度达到900℃才消失[22]。在短波数段,859、693和503 cm-1的吸收峰可分别归因于AlO4四面体配位的伸缩振动[23]、MgAl2O4中Mg-O的伸缩振动[10,24]和AlO6八面体配位的伸缩振动[25,26]。MgAl2O4:Mg干凝胶粉末在900或1000℃的烧结产物,出现一个位于428 cm-1的新吸收峰,可归因于MgO中Mg-O的伸缩振动[27~30]。由此可见,红外光谱也证实了镁颗粒在900℃以上烧结氧化成了MgO。与文献[8]对比,在铝酸镁前驱体中引入镁颗粒抑制了铝酸镁相的形成。
图3
图3
MgAl2O4:Mg干凝胶粉末在不同温度烧结后产物的FTIR图谱
Fig.3
FTIR spectra of MgAl2O4:Mg xerogel powders calcined at different temperatures
2.3 表面形貌分析
图4给出了MgAl2O4:Mg干凝胶粉末在800℃烧结获得产物的SEM照片。从图4可以看出,得到的产物呈方便面形状。对其正面和侧面观察发现,在方便面形状之上还有一些细的颗粒。这表明,在MgAl2O4前驱体中引入镁颗粒使MgAl2O4:Mg荧光粉的形貌发生了很大变化[8]。其原因是,镁颗粒在常温水溶液中不发生反应;当将柠檬酸络合物、丙烯酰胺和亚甲基双丙烯酰胺引入前驱体溶液中时,需要升温使丙烯酰胺和亚甲基双丙烯酰胺聚合,达到二者聚合的临界温度时形成三维网状的聚丙烯酰胺,聚丙烯酰胺将包络柠檬酸络合物和镁颗粒;在高温下镁颗粒迅速发生放热反应释放出气体,使柠檬酸络合物结构发生弯曲粘连;在高温烧结时除去有机物杂质,很容易得到粘连团聚的方便面形状的MgAl2O4:Mg荧光粉。因为得到凝胶非常快,镁颗粒虽然发生了放热反应却很难发生实质性的反应,由此用XRD、FTIR光谱分析800℃烧结产物难以发现其它类型的镁氧化物或氢氧化物。根据杨华等[31,32]的报道,用两步聚丙烯酰胺凝胶法很容易得到0~3型核壳结构金属氧化物复合物。由于实验条件的限制,本文的实验只能推测出镁颗粒在较低温度烧结很难氧化。
图4
图4
MgAl2O4:Mg干凝胶粉末在800℃烧结后产物的SEM照片
Fig.4
SEM images of MgAl2O4:Mg xerogel powders calcined at 800°C (a) overall view; (b) front view; (c) lateral view
2.4 光学性质
紫外可见漫反射光谱可用于分析合成样品的颜色性质、光吸收能力和能带(Eg)值。图5a给出了MgAl2O4:Mg干凝胶粉末在不同温度烧结产物的紫外可见漫反射光谱。可以看出,所有样品的反射率随着波长的增大先下降后提高。在600℃煅烧的MgAl2O4:Mg干凝胶粉末的反射率在<250 nm和320~750 nm波长范围内最低。在700℃煅烧的MgAl2O4:Mg干凝胶粉末的反射率在250~320 nm和>750 nm波长范围内出现了反常。变化趋势表明,在600℃煅烧的MgAl2O4:Mg干凝胶粉末的反射率曲线与其它几个样品不同,得到的样品还处于非晶态。在700℃煅烧的MgAl2O4:Mg干凝胶粉末的反射率在<230 nm的范围比其它样品高,表明相纯度和结晶度对样品的反射率有极大的影响。当MgAl2O4:Mg干凝胶粉末在800℃烧结时,产物的反射率曲线基本趋于稳定。继续提高烧结温度则出现MgO,导致200~450 nm范围内反射率的变化较大。由紫外可见漫反射光谱可知,MgAl2O4:Mg干凝胶粉末在不同温度烧结产物的颜色可能不同。
图5
图5
MgAl2O4:Mg干凝胶粉末在不同温度烧结后产物的紫外可见漫反射光谱和紫外可见吸收光谱
Fig.5
UV-Vis diffuse reflectance spectra (a), UV-Vis absorption spectra (b) of MgAl2O4:Mg xerogel powders calcined at different temperatures
根据文献[33,34]可计算MgAl2O4:Mg荧光粉的颜色坐标(L*, a*, b*)、色度参数(c*)、色彩角(H°)和色差(ECIE*),这里L*代表黑色(0)→白色(100),a*代表绿色(-)→红色(+)和b*代表蓝色(-)→黄色(+)。通过计算,表1给出了MgAl2O4:Mg荧光粉的颜色坐标(L*, a*, b*)、色度参数(c*)、色彩角(H°)和色差(ECIE*)。对于白颜色的样品,主要观察L*值的变化。从表1可以看出,L*值随着烧结温度的提高先增加后减小。当样品的结晶度较低甚至处于非晶态时,L*值约为55.878,颜色为灰棕色,与图6(1)中样品的实物照片一致。L*值随着烧结温度的提高而增加,主要是MgAl2O4的结晶度增加,颜色达到稳定。进一步提高烧结温度时,MgO成相,导致其L*值有所下降。从表1也可以看出,ECIE*的变化趋势与L*值一致。b*和c*的值随着烧结温度的提高而减小,而a*和H°呈无规则变化。虽然如此,却不影响样品颜色的判断,实物照片如图6所示。在800℃煅烧的MgAl2O4:Mg干凝胶粉末的L*值最大,说明该样品具有最亮的白色(图6(3))。在1000℃烧结的MgAl2O4:Mg干凝胶粉末,样品由亮白色稍微变暗。从漫反射谱中可以看出,烧结温度为700℃~800℃的样品其反射率发生了很大的变化,色度参数的变化已非常大,样品的颜色也由白中带灰变为白色。其主要原因是,在烧结过程中MgAl2O4:Mg前驱体有机物杂质迅速减少,MgAl2O4主晶格衍射峰强度,如图2所示。这一现象,MgFe2O4干凝胶在500和600℃烧结时也能被观察到[34]。
表1 MgAl2O4:Mg干凝胶粉末在不同温度烧结后产物的色度参数和Eg值
Table 1
Sample | Color coordinates | Eg /eV | |||||
---|---|---|---|---|---|---|---|
L* | a* | b* | c* | Ho | ECIE* | ||
600 | 55.878 | 5.226 | 13.080 | 14.085 | 68.221 | 57.626 | 2.090 |
700 | 70.892 | 0.345 | 10.249 | 10.296 | 88.072 | 71.636 | 3.643 |
800 | 98.318 | -0.497 | 4.307 | 4.336 | -83.418 | 98.414 | 3.803 |
900 | 98.049 | -0.531 | 3.055 | 3.101 | -80.140 | 98.098 | 4.027 |
1000 | 97.652 | -0.161 | 2.391 | 2.396 | -86.148 | 97.681 | 3.970 |
图6
图6
MgAl2O4:Mg干凝胶粉末在不同温度烧结后产物的实物照片
Fig.6
Real photos of MgAl2O4:Mg xerogel powders calcined at different temperatures (1) 600℃; (2) 700℃; (3) 800℃; (4) 900℃; (5) 1000℃
根据Kubelka-Munk(K-M)理论可将MgAl2O4:Mg荧光粉的紫外可见漫反射光谱转换为紫外-可见吸收光谱[27]。图5b给出了MgAl2O4:Mg干凝胶粉末在不同温度烧结产物的紫外可见吸收光谱图。对于在600◦C烧结的MgAl2O4:Mg干凝胶粉末得到的非晶态样品,在200~850 nm波长范围具有很宽的吸收带。与MgAl2O4相比,得到了类似的结果,可见非晶态的样品的光吸收能力类似。当烧结温度提高到700◦C时,光吸收范围缩减为200~500 nm。在274 nm观察到一个强的吸收峰,是阴离子空位F+心引起的[35]。随着烧结温度进一步提高,在215和452 nm观察到两个新的吸收峰,可分别被归因于MgO中的F心[35]和O2--Al3+间的电荷转移[36]。紫外可见吸收光谱分析结果进一步表明,在900℃烧结出现了MgO相,且烧结温度和Mg颗粒对整个体系的颜色和光吸收性质有重要的影响。
图7
图7
MgAl2O4:Mg干凝胶粉末在不同温度烧结后产物的Eg值及其与烧结温度的关系
Fig.7
Eg
2.5 发光性质
图8给出了MgAl2O4:Mg干凝胶粉末在800℃烧结产物的荧光光谱图。从图8可见,荧光光谱集中在635~690 nm波长范围内。使用Origin 8.0软件可将其拟合为三个高斯峰,分别位于650、656和680 nm。对于纯MgAl2O4,在395和425 nm处可观察到两个荧光峰[8]。而引入镁颗粒后,395和425 nm两个荧光峰淬灭。Kato等[38]发现,MgO陶瓷在600 nm附近有一强发射峰,但是没有分析其机理。Panin等[39]用简单的湿化学法合成了颗粒尺寸约为500 nm的MgO,在696 nm附近出现一个点缺陷引起的强荧光发射峰。Cui等[40]用共沉淀法合成了纯MgO,在325 nm波长的光激发下在650和666 nm出现了强荧光发射峰。这些发射峰是氧空位、镁空位、间隙氧和缺陷引起的。对于在900和1000℃烧结得到的MgAl2O4:Mg样品,其发射峰主要由氧空位和镁空位引起。
图8
图8
MgAl2O4:Mg干凝胶粉末在800℃烧结后产物的荧光光谱
Fig.8
Fluorescence spectra of MgAl2O4:Mg xerogel powders calcined at 800℃
图9
图9
MgAl2O4:Mg干凝胶粉末在800℃烧结后产物的色度
Fig.9
CIE diagram of MgAl2O4:Mg xerogel powders calcined at 800℃
图10
图10
荧光强度与烧结温度的关系
Fig.10
Relationship between luminescence intensity at 650 nm and sintering temperature
2.6 发光机理
基于能带排列理论构建的多元复合物半导体增强发光的能带排列方式,有I型能带排列、II型能带排列和III型能带排列[43~46]。MgAl2O4:Mg属于特殊的II型能带排列。为了详细的分析MgAl2O4:Mg荧光粉的发光机理,图11给出了MgAl2O4和Mg颗粒的能级图。根据能带理论,激光照射到MgAl2O4:Mg荧光粉,使电子从MgAl2O4的价带跃迁到导带,从而在价带留下空穴。跃迁到导带的电子,一部分经由费米能级进入镁颗粒的价带。由于金属颗粒的导带和价带重合电子很容易跃迁到其导带,通过表面等离子体共振(SPR)散射回MgAl2O4的导带[47,48]。根据文献[47],这一现象导致主晶格相的带边发射淬灭。MgAl2O4的荧光发射峰集中在395和425 nm,而本文的实验中并未观察到相关的荧光发射峰,就是这一原因所致。此外,跃迁到MgAl2O4导带的电子在缺陷能级等的作用下弛豫到更低的能级,进而与价带空穴复合,多余的能量以光子的形式释放。较高能级上的电子继续向更低能级弛豫,最终与MgAl2O4导带的空穴复合并发射光子。由此可见,将镁颗粒引入到MgAl2O4系统中使MgAl2O4的本征发射淬灭,在缺陷等的作用下产生了新的荧光发射峰。
图11
图11
MgAl2O4:Mg荧光粉的发光机理
Fig.11
Photoluminescence mechanism of MgAl2O4:Mg phosphors
3 结论
用超声辅助聚丙烯酰胺凝胶法可合成新颖的方便面型MgAl2O4:Mg荧光粉。在MgAl2O4体系中引入Mg金属颗粒抑制了MgAl2O4相的形成,且只有在900℃及以上的温度烧结镁颗粒才能氧化成MgO。随着烧结温度的提高能带值先增大后稍减小,颜色由暗棕色变为白色。镁颗粒的引入使MgAl2O4本征发射峰淬灭,主要是金属颗粒的表面等离子体共振所致;在650、656和680 nm出现三个新的荧光发射峰,是缺陷能级引起的。
参考文献
Physical properties of MgAl2O4, CoAl2O4, NiAl2O4, CuAl2O4, and ZnAl2O4 spinels synthesized by a solution combustion method
[J]. .,
MgAl2O4 spinel powders from oxide one pot synthesis (OOPS) process for ceramic humidity sensors
[J]. .,
Hot isostatic pressing of MgAl2O4 spinel infrared windows
[J]. .,
Transparent polycrystalline MgAl2O4 ceramic fabricated by spark plasma sintering: Microwave dielectric and optical properties
[J]. .,
Synergistic effects of optical and photoluminescence properties, charge transfer, and photocatalytic activity in MgAl2O4: Ce and Mn-Codoped MgAl2O4: Ce phosphors
[J]. .,
Investigation on preparation and transparent mechanism of MgAl2O4 transparent nano-ceramics
[J].
MgAl2O4纳米透明陶瓷的制备及其透明机理
[J]. ,
Study on optical spectra of transparent MgAl2O4 ceramics treated with γ-irradiation and annealing
[J].
γ辐射及退火MgAl2O4透明陶瓷光谱特性研究
[J]. ,
Insight into the optical, color, photoluminescence properties, and photocatalytic activity of the N-O and C-O functional groups decorating spinel type magnesium aluminate
[J]. ,
Medium infrared transparency of MgO-MgAl2O4 directionally solidified eutectics
[J]. .,
Enhanced upconversion emission and temperature sensor sensitivity in presence of Bi3+ ions in Er3+/Yb3+ co-doped MgAl2O4 phosphor
[J]. .,
Optical analysis of interaction between Sm and Eu ions in MgAl2O4 spinel nanophosphor
[J]. ,
Dose dependence of neutron irradiation effects on MgAl2O4 spinels
[J]. .,
Optical and dielectric properties of neutron irradiated MgAl2O4 spinels
[J]. .,
Novel photoluminescence properties of magnetic Fe/ZnO composites: self-assembled ZnO nanospikes on Fe nanoparticles fabricated by hydrothermal method
[J]. .,
Synthesis and optical properties of dithiol-linked ZnO/gold nanoparticle composites
[J]. .,
Fabrication of ZnO@Ag@Ag3PO4 ternary heterojunction: superhydrophilic properties, antireflection and photocatalytic properties
[J]. ,
Preparation and photocatalytic application of ternary n-BaTiO3/Ag/p-AgBr heterostructured photocatalysts for dye degradation
[J]. .,
Single step solid-state fusion for MgAl2O4 spinel synthesis and its influence on the structural and textural properties
[J]. .,
Bioinorganic magnetic core-shell nanocomposites carrying antiarthritic agents: intercalation of ibuprofen and glucuronic acid into Mg-Al-layered double hydroxides supported on magnesium ferrite
[J]. .,This paper describes the synthesis and characterization of a composite constituted by an antiarthritic agent (AA) intercalated into a layered double hydroxide (LDH) supported on magnesium ferrite. Core-shell nanocomposites were prepared by depositing Mg-Al-NO(3)-LDH on a MgFe(2)O(4) core prepared by calcination of a nonstoichiometric Mg-Fe-CO(3)-LDH. Intercalation of ibuprofen and glucuronate anions was performed by ion-exchange with nitrate ions. The structural characteristics of the obtained products were investigated by powder X-ray diffraction, element chemical analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Morphologies of the nanocomposite particles were examined by scanning electron microscopy and transmission electron microscopy. The products were shown to intercalate substantial amounts of AA with enhanced thermal stabilities. Room-temperature magnetic measurements by vibrating sample magnetometry revealed that the products show soft ferromagnetic properties suitable for potential utilization in magnetic arthritis therapy.
Enhanced photocatalytic performance by hybridization of Bi2WO6 nanoparticles with honeycomb-like porous carbon skeleton
[J]. .,
Synthesis of spinel-metal-oxide/biopolymer hybrid nanostructured materials
[J]. .,
Synthesis and characterization of nano crystalline BaFe12O19 powders by low temperature combustion
[J]. .,
MgAl2O4 both as short and long persistent phosphor material: Role of antisite defect centers in determining the decay kinetics
[J]. .,
Elucidation of the basicity dependence of 1-butene isomerization on MgO/Mg(OH)2 catalysts
[J]. .,
Low temperature synthesis of nanocrystalline magnesium aluminate spinel by a soft chemical method
[J]. .,
Effect of local structure of Sm3+ in MgAl2O4: Sm3+ phosphors prepared by thermal decomposition of triethanolamine complexes on their luminescence property
[J]. .,
Influence of functionalized MgO nanoparticles on electrical properties of polyethylene nanocomposites
[J]. .,
Excellent fluoride removal properties of porous hollow MgO microspheres
[J]. .,
The role of MgO in the thermal behavior of MgO-silica fume pastes
[J]. .,
Environmentally friendly Baeyer-Villiger oxidation with H2O2/nitrile over Mg(OH)2 and MgO
[J]. .,
Fabrication of 0-3 type manganite/insulator composites and manipulation of their magnetotransport properties
[J]. .,
A polymer-network gel route to oxide composite nanoparticles with core/shell structure
[J]. .,
Irradiation synthesized and photoluminescence mechanism of MgAl2O4: Ce phosphor
[J].
MgAl2O4: Ce荧光粉辐照合成及发光机理研究
[J]. ,
Comparative study on optical and electrochemical properties of MFe2O4 (M=Mg, Ca, Ba) nanoparticles
[J]. .,
Synthesis of nanocrystalline MgO/MgAl2O4 spinel powders from industrial wastes
[J]. .,
A novel synthetic route for magnesium aluminate (MgAl2O4) nanoparticles using sol-gel auto combustion method and their photocatalytic properties
[J]. ,
Fabrication and photocatalytic properties of Ce-La-Ag Co-doped TiO2/basalt fiber composite photocatalyst
[J].
Ce-La-Ag共掺杂TiO2/玄武岩纤维复合光催化剂的制备和性能
[J]. ,
scintillation and dosimeter properties of MgO transparent ceramic and single crystal
[J]. .,
Luminescence from ZnO/MgO nanoparticle structures prepared by solution techniques
[J]. .,
Influence of copper doping on chlorine adsorption and antibacterial behavior of MgO prepared by co-precipitation method
[J]. .,
Synthesis and luminescence properties of hollow spherical CaMoO4: Eu3+, Li+ red phosphors
[J].
CaMoO4: Eu3+, Li+红色荧光粉空心球的制备和发光性能
[J]. ,
Hydrothermal preparation and photoluminescent property of SrMoO4: Pr3+ red phosphors
[J].
SrMoO4: Pr3+红色荧光粉的水热合成及光致发光
[J]. ,
Design of ternary CaTiO3/g-C3N4/AgBr Z-scheme heterostructured photocatalysts and their application for dye photodegradation
[J]. .,
Fabrication of ZnO@MoS2 nanocomposite heterojunction arrays and their photoelectric properties
[J]. ,
Preparation and promising application of novel LaFeO3/BiOBr heterojunction photocatalysts for photocatalytic and photo-Fenton removal of dyes
[J]. .,
Fabrication of ZnO@Ag3PO4 core-shell nanocomposite arrays as photoanodes and their photoelectric properties
[J]. ,
Photoluminescence (PL) quenching and enhanced photocatalytic activity of Au-decorated ZnO nanorods fabricated through microwave-assisted chemical synthesis
[J]. .,
/
〈 | 〉 |