稀土Sm掺杂棒花状ZnO的制备及其光催化性能研究

由硝酸锌、硝酸钐、十二烷基硫酸钠制备Sm掺杂棒花状纳米氧化锌,考察制备温度、分散剂浓度、Sm掺杂等因素对氧化锌形貌和光催化性能的影响,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、能量色散X射线谱(EDS)、X射线光电子能谱(XPS)进行表征。结果表明,制备温度、分散剂浓度、Sm掺杂量等对棒花状纳米氧化锌的形貌和光催化性能有显著的影响。在60℃下,分散剂浓度为28 mmol/L、Sm掺杂量为5%时,所制备的棒花状纳米氧化锌的形貌规整且光催化性能最好。     

Sm掺杂TiO_2光催化剂的制备与催化性能的研究

采用溶胶-凝胶法制备Sm掺杂TiO2催化剂,并用X射线衍射、TEM等技术表征了催化剂,考察了催化剂的煅烧温度、催化剂用量以及掺杂量对光催化降解甲基橙效率的影响。结果表明:催化剂煅烧温度为500℃,最佳用量为100mg/mL,钐的最佳掺杂量为Sm/Ti摩尔比1%。     

Y掺杂ZnO的制备及其光催化性能

采用化学沉淀法制备Y/ZnO光催化剂,以光催化降解甲基橙为探针反应,考察Y掺杂的ZnO光催化活性,并采用X射线衍射、红外光谱和紫外漫反射等手段对其进行结构表征.结果表明,Y掺杂的ZnO光催化剂对甲基橙降解具有良好的活性.活性及催化剂结构表征结果表明,最佳Y掺杂质量分数为0.1%,以掺杂Y质量分数为0.1%的Y/ZnO为...     

稀土Sm掺杂棒花状ZnO的制备及其光催化性能研究

由硝酸锌、硝酸钐、十二烷基硫酸钠制备Sm掺杂棒花状纳米氧化锌,考察制备温度、分散剂浓度、Sm掺杂等因素对氧化锌形貌和光催化性能的影响,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、能量色散X射线谱(EDS)、X射线光电子能谱(XPS)进行表征。结果表明,制备温度、分散剂浓度、Sm掺杂量等对棒花状纳米氧化锌的形貌和光催化性能有显著的影响。在60℃下,分散剂浓度为28 mmol/L、Sm掺杂量为5%时,所制备的棒花状纳米氧化锌的形貌规整且光催化性能最好。     

V掺杂ZnO薄膜磁控溅射制备及其压敏性能

用磁控溅射成功制备出V掺杂ZnO压电薄膜。在不同温度对样品进行退火处理,采用扫描电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱仪(XPS)对薄膜的表面形貌、晶体结构和表面化学状态进行表征,并测量了不同退火温度下薄膜样品的电流密度(J)-电压(V)曲线。结果表明,高温退火后V向ZnO晶格内部迁移,引起晶格畸变,形成表面氧空位。随着退火温度的升高,非线性系数先增大后减小,薄膜的压敏电压逐渐增大,漏电流密度先减小后增大。800℃退火后样品表面氧空位浓度最高,薄膜具有较为理想的综合电性能,其非线性系数为15.19,压敏电压为5.13 V,漏电流密度为0.42μA·mm^-2。     

单分散球形Sm掺杂的CeO2粉体的均相沉淀法制备

由均相沉淀法制备了Sm掺杂的CeO2粉体(SDC), 即在硝酸盐溶液中加入过量的尿素, 加热使尿素分解释放OH-生成沉淀, 经过滤、洗涤、焙烧得到所需的粉体.通过控制反应条件可对粉体的形貌和粒径进行控制.在500 ℃焙烧的粉体是面心立方相, 随着焙烧温度的提高, 晶型不变, 晶粒尺寸增大.将600 ℃焙烧的粉体压片在1 500 ℃烧结, 其相对密度达到95%以上, 其电导率在800 ℃能达到0.07 S*cm-1.     

白光LED用Ce，Sm共掺杂YAG单晶荧光材料的光谱性能

对白光发光二极管（light-emitting diode,LED）用Y3Al5O12（YAG）单晶荧光材料的制备和光谱性能进行了研究。采用提拉法生长了白光LED用Ce：YAG及Sm,Ce：YAG晶体,并通过吸收光谱、激发光谱和发射光谱等对晶体的光谱特性进行表征。结果表明：Ce：YAG单晶作为荧光材料被发射波长460 ...     

掺杂铽的稀土酒石酸配合物的合成及其荧光性能研究

采用溶液反应法合成了掺杂铽的稀土酒石酸配合物Ln2-xTbxL3(Ln=Y,La,Gd),通过无素分析,X射线粉末衍射及红外光谱等对其组成进行了表征,测定了该系统配合的荧光光谱,实验结果表明,该系列配合物的组成为Ln2-xTbxl3.6H2O(Ln=L,La,Gd）,该掺杂配合物比单纯配合物Tb2L3具有更好的发光性能,而且当x=0.7-1.5时,该掺杂配合物的发光最强,据此探讨同多核稀土酒石酸配合物及杂多核烯土酒石酸配合物发光机理。     

共掺杂ZnO纳米材料的制备及光学性能研究

利用共沉淀法制备了Y和Cd共掺杂的ZnO纳米材料。X-射线衍射分析表明,样品为单一相的ZnO纤锌矿结构,随着掺杂量的增加,样品的晶粒尺寸减小。光学性能测试结果表明,样品具有较强的紫外发射峰和较弱的可见光发射峰,紫外发射峰强度随着掺杂量的增加而减弱并发生红移。     

水热法制备钐掺杂氧化锌及其对二甲胺气敏性能

采用水热法在不加任何助剂的情况下制备了六方纤锌矿ZnO及掺杂钐的ZnO (ZnO:Sm)粉体材料. 气敏测试结果显示,ZnO:Sm材料对二甲胺具有较高的灵敏度,随着二甲胺浓度增加,灵敏度呈现线性增加,当二甲胺气体的浓度为1.00′10-4时该气体传感器的检测灵敏度可达到63.97. 在三甲胺气氛中,ZnO:Sm对二甲胺具有优异的选择性,对二甲胺的响应时间为6 s,恢复时间为19 s.     

Superoxide anion: Critical source of high performance antibacterial activity in Co-Doped ZnO QDs

In this paper, Co-doped ZnO quantum dots (QDs) with smaller lateral size and high stability were prepared via a simple and one-step sol-gel method. We found that Co-doped ZnO QDs could more effectively absorb visible light and motivate the separation efficiency of photogenerated electrons and holes, resulting in the over yield production of superoxide anion (^.O₂^-) and hydroxyl radical (^.OH) under environmental condition. As a result, the antibacterial activity of Co-doped ZnO QDs was drastically improved than that of bare ZnO QDs, and the superoxide radicals mediated oxidative stress plays a dominant role in the antibacterial mechanism. Besides, controllable construction of smaller size Co-doped ZnO QDs was favoured for the contact between the nanoparticles and bacteria, thus significantly decreased the transmission path of ROS and Zn²⁺, causing the markedly enhanced antibacterial activities.     

掺杂ZnO光催化剂研究进展

ZnO作为半导体光催化剂,具有无毒性、高效性和低成本等优点得到广泛研究。但是ZnO禁带宽度较宽,为3.37 eV,仅能吸收紫外光,而且光生电子和空穴较容易复合,在太阳光照射下,表现出较低的光催化活性,不能满足工业应用要求。对ZnO进行改性能够提高ZnO对可见光的利用率及光催化活性。其中,对ZnO进行掺杂能够有效改变光催化剂的比表面积、颗粒大小和光催化活性等性质,适当引入一些金属或非金属离子有可能使催化剂对光的吸收范围扩展到可见光区。金属掺杂能使ZnO形成更多的晶格缺陷,降低电子和空穴的复合几率;而非金属掺杂能够在ZnO晶格中引入氧空位以及引起ZnO晶格膨胀,使ZnO禁带变窄,进而能吸收可见光;同时,掺杂两种非金属有可能比掺杂单一非金属更能改善ZnO对可见光的吸收。结合金属掺杂与非金属掺杂的优点,金属与非金属共同掺杂到ZnO中,使ZnO的各种缺点得到全面改善。此外,利用金属氧化物对ZnO进行掺杂,可改变ZnO晶格结构以及表面电子状态,提高ZnO光催化活性。需加强对掺杂理论的研究,掺杂虽能使ZnO能够吸收可见光,但是对可见光吸收不强,对太阳能利用率不高,需要对ZnO改性方法进行更深入研究,同时,光催化要进一步在工业上进行应用,应加强对光催化降解多组分废水及真实废水进行研究,其稳定性、固载化及其回收利用方面也应该得到更多关注。     

Preparation of rGO/AgCl QDs and its enhanced photoelectrocatalytic performance for the degradation of Tetracycline

A novel rGO/AgCl QDs composites have been obtained by an ultrasonic-assisted method for the first time. Photoelectrocatalytic (PEC) performances of the obtained samples were studied by the degradation of 20 mg/L Tetracycline (TC) under visible light irradiation with an applied bias potential of 1.5 V (vs Ag/AgCl). Degradation of TC by different processes including Photocatalysis (PC), Electrocatalysis (EC), and PEC was compared, and the effect of different bias potential on the PEC degradation of TC was discussed. Results showed that rGO/AgCl QDs composites had displayed superior PEC activity than that of pristine AgCl QDs with degrading 85.2% of TC during 120 minutes, which was about 1.5 times higher than that of AgCl QDs (33%). Besides, compared to PC and EC removal of TC, PEC process showed the highest degradation efficiency of TC (85.2%) by rGO/AgCl QDs, which was about three times and one time higher than that of PC (39.18%) and EC (20.73%) system, respectively. Moreover, the reusibility and stability of the samples were tested by five times cycling tests, and results demonstrated that the stability of bare AgCl QDs was improved after the introduction of rGO. The enhanced PEC activity and stability of the samples could be attributed to the intimate contact between rGO and AgCl QDs and external electric field, which had benefitted the formation of more active sites and accelerated electron-hole separation.     

Influence of low concentration Sm doping on optical and catalytic performance of titania

The work focuses on exploring the effect of the concentration of Sm dopant (0.2–0.6 at.%) on structural, optical and photocatalytic properties of the spin coated titania based thin films annealed at different temperatures. The optical interpretation involves the influence of Sm doping on optical constants and luminescence behaviour of the samples. The comprehensive work on optical bandgap, Urbach energy and electron-phonon interaction strength was conducted for Sm doped samples. The optical band gap was found to increase with the increasing concentration of Sm, but decreased with high temperature annealing. Using ellipsometry measurement, refractive index of the samples was obtained. The orbital level information was gathered using X-Ray Photoelectron Spectroscopy (XPS) study with a special emphasis on the evolution of physico-chemical properties as function of Sm doping. The XPS study confirms the presence of Sm in the titania host material and it helped in estimating defects induced by Sm doping. The photocatalytic study of Sm doped titania thin films was carried out by using methylene blue (MB) and Rhodamine B (RhB) dye and we have found an enhanced photocatalytic activity for the 0.4 at.% Sm doped samples.     

Solar driven photocatalytic properties of Sm3+ doped ZnO nanocrystals

ZnO nanocrystals (NCs) doped with different Sm³⁺ concentrations were prepared by sol gel method. XRD analysis showed that the ZnO:Sm³⁺ NCs crystallized in the hexagonal wurtzite structure with a grain size varying from 61.4 nm to 72.6 nm, with Sm³⁺ concentration. Transmission electron microscopy (TEM) images indicated that ZnO NCs adopted a bimodal size distribution. X-ray photoelectron spectroscopy (XPS) revealed that Sm ions existed in trivalent state and substituted at the Zn²⁺ sites in the ZnO lattice. Raman spectra highlighted the presence of the LO mode, confirming the successful substitution of Zn²⁺ by Sm³⁺. Excitation and emission spectra highlighted the typical 4f-4f transitions of Sm³⁺. A photoluminescence (PL) quenching accompanied by a decrease of PL lifetime was observed for Sm³⁺ concentrations above 1.5%. The processes of excitation and de-excitation of the Sm³⁺ ions in ZnO NCs were discussed based on dipolar interactions between the excited ions. The ZnO:Sm³⁺ (1.5%) photocatalyst induced complete and fast photodegradation of RhB under sunlight irradiation. The photocatalytic mechanism is discussed based on the analysis of PL lifetimes. The role of oxygen vacancies on the reduction of Sm³⁺ ions and its impact on the photocatalytic process is also discussed.     

稀土钕掺杂氧化锌纳米材料的制备及对罗丹明B的降解研究

采用直接沉淀法对纳米氧化锌做稀土掺杂改性,制备了钕掺杂纳米氧化锌,并采用X射线衍射、扫描电子显微镜、固体荧光光谱等测试手段对产品做了分析与表征,考察掺杂对氧化锌的物相、晶体结构、荧光性质的影响,将其应用于废水中罗丹明B的光催化降解。结果表明：钕掺杂可大幅度提高纳米氧化锌在汞灯照射下的光催化性能。随着掺杂量增加,掺杂氧化锌纳米材料的光催化降解性能逐渐升高,掺加7%（物质的量分数）钕的纳米氧化锌对罗丹明B的去除率可达89.62%。     

Co掺杂ZnO微球的光降解及抗菌性能研究

采用简单的水热法制备不同Co掺杂量的ZnO微球。通过X射线衍射、X射线光电子能谱、扫描电镜等技术对Co-ZnO进行结构、形貌及光学性质分析。以亚甲基蓝为模型研究Co-ZnO在模拟太阳光下的催化性能,并以大肠杆菌为模型研究其抗菌活性。结果表明,在制备的催化剂中,物质的量分数5%Co-ZnO具有最佳的光催化及抗菌性能,这可能是由于掺杂的Co离子能够进入ZnO晶格中改变ZnO带隙宽度,且能够抑制在反应过程中产生的光生电子-空穴的复合,从而促进ZnO的光催化及抗菌性能。     

不同方法合成掺杂ZnO粉体制备ZnO压敏电阻

分别采用低温固相化学法和共沉淀法合成掺杂ZnO粉体,并用这两种粉体在不同温度下烧结制备了ZnO压敏电阻。借助XRD、SEM、TEM、BET等检测手段对粉体产物的性能进行了表征,采用XRD、SEM等手段对ZnO压敏陶瓷的物相、结构进行了分析,并对两种方法制备的粉体及压敏电阻的性能进行了比较研究。结果表明:采用低温固相化学法合成的粉体平均粒径为23.95 nm,用其制备ZnO压敏电阻的最佳烧结温度是1 080℃,其电位梯度为791.64 V/mm,非线性系数是24.36;采用共沉淀法合成的粉体平均粒径为188 nm,用其制备ZnO压敏电阻的最佳烧结温度是1 130℃,其电位梯度为330.99 V/mm、非线性系数是19.70,低温固相化学法制备的ZnO压敏电阻性能优于共沉淀法制备的ZnO压敏电阻。     

Preparation of Ag-sensitized ZnO and its photocatalytic performance under simulated solar light

ZnO was prepared rapidly by microwave heating method. The results of scanning electron microscopy show that the leaflike ZnO is composed of self-assembled ZnO particles of 30–50 nm. Ag-sensitized ZnO composite was prepared by UV-photoreduction and glycol reduction, respectively. The composite was characterized by means of scanning electron microscopy, X-ray diffraction and photoluminescence. The ZnO and Ag/ZnO prepared were applied in photocatalytic degradation of phenol and methyl orange as model of organic pollutant in water under simulated solar light. The results show that Ag doping in both methods of UV-photoreduction and glycol reduction can remarkably improve the photocatalytic activity of ZnO under simulated solar light. The utilization ratio of Ag in glycol reduction is high and the optimum content of Ag in Ag/ZnO composite is only 1.33%. Therefore, the glycol reduction is a novel and excellent method for preparing Ag-sensitized ZnO composite with high photocatalytic activity.     

锰掺杂氧化锌纳米颗粒的制备及抗菌性能评价

采用一种简单的固相研磨方法制备氧化锌及锰掺杂的氧化锌纳米颗粒。利用透射电子显微镜、X射线粉末衍射对样品进行结构表征。以抑菌圈实验,最小抑菌浓度和抗菌动力学曲线对样品抗菌活性进行测试。结果表明,掺杂质量分数0.5%的锰可以显著提高暗态下氧化锌的抗菌活性。与未掺杂氧化锌纳米颗粒相比,其最小抑菌浓度显著减小,失活动力学常数明显增大,而这种活性的提高有可能是锰掺杂导致氧化锌晶体缺陷增多所致。