Bi_2MoO_6/Ni-FeLDH复合材料的制备及可见光催化性能

采用水热法和共沉淀法结合制备Bi2MoO6/Ni-Fe LDH复合材料,通过XRD、FT-IR、SEM、TEM、XPS和N2物理吸附等对样品的结构和形貌进行表征。以甲基橙、亚甲基蓝、罗丹明B和苯酚为目标降解物,在可见光下进行复合材料的光催化性能测试,以降解甲基橙溶液为例研究复合材料的光催化反应机理。结果表明,复合材料的BET比表面积随着Ni-Fe LDH含量的增加而增大,光催化活性明显提高。Bi2MoO6/Ni-Fe LDH复合材料中Ni-Fe LDH的含量为4.5%时具有最好的光催化效果,可见光照射60min,甲基橙的降解率达91%,较Bi2MoO6和Ni-Fe LDH分别提高52%和16%。Bi2MoO6/Ni-Fe LDH复合材料具有良好的稳定性,循环使用5次,甲基橙(MO)的降解率为88%。复合材料光催化降解甲基橙反应遵循一级反应动力学。     

胶体碳微球的活化及其亚甲基蓝液相吸附性能的研究

以葡萄糖为前驱体,采用液相碳化法,制备颗粒约为100～200nm胶体碳微球.采用KOH作活化剂对胶体碳微球进行活化处理.考察了碱炭比、活化温度和保温时间等工艺因素对孔径和比表面积的影响.通过XRD、SEM等分析手段对胶体碳微球活化前后的表面形貌、孔径分布、显微结构进行分析.经热处理和活化后,胶体碳微球的BET比表面积从26.6m2/g增加到1383.4m2/g.相同实验条件下,在亚甲基蓝液相吸附试验中,经活化处理后的样品所表现出的吸附量是商业活性炭Calgon-F300的两倍.     

分级介孔结构组成的ZnO微球及光催化性能

以硝酸锌、脲素及酒石酸为反应物, 采用水热法制备碱式碳酸锌前驱体微球, 通过煅烧前驱体制备了介孔氧化锌微球。通过扫描电子显微镜(SEM)可以观察到, 氧化锌微球的直径约为2~4 μm, 由大量厚度约为10 nm的介孔纳米片组装而成。X 射线衍射(XRD)和透射电镜(TEM)结果表明: ZnO微球为六方纤锌矿结构, 并结晶较好。比表面积测试(BET)表明ZnO微球为介孔材料, 孔径为20~50 nm, ZnO微球比表面积约为29.8 m²/g。以亚甲基蓝为目标降解物, 对介孔氧化锌微球进行了光催化降解实验。实验结果表明, 所合成的介孔ZnO微球对亚甲基蓝的光催化性能较好。     

碳包覆ZnO-TiO_2纳米纤维的制备及其太阳光催化性能

采用溶胶-凝胶法和静电纺丝法制备ZnO-TiO_2纳米纤维和碳包覆ZnO-TiO_2纳米纤维,以扫描电镜、热重-差示热量、红外光谱、X射线衍射和比表面积分析等方法进行表征。以10mg/L亚甲基蓝溶液为底物,研究了ZnO掺杂量对亚甲基蓝光催化降解性能的影响。结果表明:ZnO的质量分数为3%的碳包覆ZnO-TiO_2纳米纤维光催化性能最高,太阳光照射6h时亚甲基蓝的降解率达到94.4%。对其光催化机理进行了简要分析。     

纳米颗粒包覆ZrW_2O_8空心结构的制备和性能

采用包覆法制备单一相钨酸锆(ZrW2O8)空心球。研究选择以水热合成法制备的胶体碳球作为制备空心球的模板,通过溶胶—凝胶法制备了具有网状结构的钨酸锆前驱体凝胶,经过后续简单的包覆过程得到胶体碳球—钨酸锆凝胶形成的壳核结构,并对该壳核结构进行煅烧(610℃保温10h)后除去碳球模板得到ZrW2O8空心球。实验所得ZrW2O8空心球平均粒径约3μm,球壳平均厚度为1.5μm,构成壳层结构的纳米级ZrW2O8颗粒为棒状无规则多面体,尺寸约500nm×50nm×50nm。FTIR和TG-DTA分析证明,产物为立方相ZrW2O8空心球,密度为2.8g/cm3,比理论值降低了45%;产物空心球具有良好的负热膨胀特性,在室温至200℃的温度区间内,负膨胀系数略低于理论值,平均热膨胀系数为-11.4×10-6K-1。     

空心状TiO_2的模板法制备及光催化性能研究

以蔗糖为碳源,采用水热法合成了碳球模板剂,再以钛酸四丁酯(TBOT)为钛源,使纳米TiO2沉积于碳球上,经高温煅烧制备TiO2空心球并研究了其对亚甲基蓝光催化降解的性能。结果表明,在最佳制备条件及使用量下,紫外光照150min后,TiO2对亚甲基蓝的降解率可达到86.8%。SEM、TEM及XRD结果表明制得的TiO2呈不规则空心球状,壁较薄且结构疏松,具有锐钛矿相。相比商品化P25,空心球的禁带宽度稍有变宽,但相同条件下的光降解性能仍优于P25。     

介孔TiO2/WO3空心球的制备及其可见光光催化性能

以硫酸氧钛和偏钨酸铵为前驱体, 以柠檬酸作为络合剂, 采用喷雾干燥-高温煅烧两步法制备了介孔TiO₂/WO₃空心球复合材料。利用SEM、TEM、BET、XRD、UV-Vis DRS等手段对样品的形貌、微结构、比表面积、晶相组成和光学性能进行了表征和分析, 以亚甲基蓝为模拟降解物考察其光催化性能。结果表明: 复合材料为介孔空心球状结构, 球体分散好, 直径主要分布在1 μm左右; 球壁由纳米颗粒和空隙构成, 随着煅烧温度的升高, 颗粒粒径不断增大, 空隙孔径不断增大。性能研究结果表明, TiO₂与WO₃复合后, 样品对光的吸收范围扩展到了可见光区域, 这有利于提高太阳光的利用率; 当前驱体中WO₃含量为3mol%, 样品的煅烧温度为500℃时, 复合材料具有最好的光催化性能: 对亚甲基蓝降解率可达99.1%, 而P25的降解率仅为29.5%。     

多孔Ag/TiO2的制备及其光催化性研究

以工业TiOSO4溶液水解得到的多孔偏钛酸为载体,通过光催化还原法制备了多孔Ag/TiO2光催化剂.用XRD、SEM、EDS及低温氮吸附脱附法对样品进行了表征.以光催化氧化降解亚甲基蓝为目标反应,考察了不同制备条件对样品光催化活性的影响.结果表明,制备的Ag/TiO2为负载有非晶态纳米银粒的锐钛矿型TiO2光催化剂,比表面积高达197m2/g,其光催化活性远优于未载银的TiO2.     

Er3+掺杂TiO2空心球的制备及其光催化性能研究

以钛酸四丁酯、氧化铒、硝酸等为原料, 采用碳球模板法制备了TiO₂: Er³⁺空心球材料, 利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)等测试方法, 对样品的结构和形貌进行了表征。并利用紫外-可见(UV-Vis)分光光度计考察了TiO₂: Er³⁺空心球材料在催化染料罗丹明B、亚甲基蓝、茜素红、甲基橙的脱色降解过程中的应用性能。系统研究了Er³⁺掺杂浓度、不同离子型染料和染料水溶液的pH等因素对催化降解效率的影响。实验结果表明: 经600℃煅烧3 h制备的TiO₂: Er³⁺为锐钛矿晶型, 空心球结构, 尺寸均匀, 粒径约为120 nm, 比表面积约为60.5 m²/g; Er³⁺掺杂量为0.5mol%的样品对甲基橙染料的催化降解效率最高; 对四种不同离子型染料, 茜素红的催化降解效果显著, 在紫外光照射下, 催化效率较未掺杂Er³⁺的TiO₂提高了约30%。     

不同晶型BiVO_4微球的制备及其对光催化性能的影响

以Bi（NO3）3、NH4VO3为原料,NaOH为pH调节剂,采用微波水热法在180℃制备了BiVO4微球,分析了不同煅烧温度对晶型、形貌的影响,并进一步探讨了BiVO4晶型与其光催化性能的关系。采用XRD、SEM和UV-Vis吸收光谱对产品进行了分析表征,并以光催化降解亚甲基蓝为模型反应研究BiVO4的光催化性能。结果表明所制备的BiVO4微球是四方相结构,球的直径在1～3μm之间,将其在500℃煅烧后发生晶型转变,600℃煅烧可得到纯单斜相BiVO4微球,且具有良好的可见光催化活性。而且,不同晶型的BiVO4影响亚甲基蓝的降解效果。     

Construction of hierarchical nanostructured TiO2/Bi2MoO6 heterojunction for improved visible light photocatalysis

In this study, Bi2MoO6 hollow microspheres were modified by depositing TiO2 nanoparticles through a simple hydrothermal method. The prepared TiO2/Bi2MoO6 photocatalysts were characterized by scanning and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The photocatalytic performance of the heterostructured catalysts was evaluated by degradation of methylene blue (MB) under visible-light irradiation (lambda>420 nm). The photocatalysts based on nanostructured Bi2MoO6 and TiO2 exhibit much higher photocatalytic activity than the single-phase Bi2MoO6 or TiO2 and the mechanical mixture of Bi2MoO6 and TiO2 for degradation of MB under the same conditions. The results reported in this study provide insight into constructing other heterostructured photocatalysts.     

Preparation and photocatalytic activity of hollow ZnO and ZnO-CuO composite spheres

ZnO and ZnO-CuO composite hollow spheres were fabricated by using colloidal carbon spheres as templates. The morphology, structure and chemical composition of the as-prepared samples were investigated using field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The photocatalytic activity of the hollow spherical products was evaluated by photocatalytic degradation of methylene blue (MB) aqueous solution at ambient temperature. The results indicated that the ZnO-CuO composite hollow spheres display higher photocatalytic efficiency than pure hollow ZnO products. The related photocatalytic mechanism was discussed based on the microstructure and properties of the ZnO and ZnO-CuO composite hollow spheres. The facile strategy for the preparation of ZnO-CuO hollow nanostructures can be applicable to the synthesis of other composite hollow spheres.     

沙柳基磁性多孔炭的制备及其吸附亚甲基蓝性能研究

采用水热法原位改性沙柳生物炭制备磁性多孔炭复合材料,利用SEM、XRD、FT-IR、XPS和BET分别对多孔炭的形貌、结构表征,并研究磁性多孔炭吸附去除废水中亚甲基蓝性能。系列表征分析结果表明磁性复合材料表面疏松多孔,比表面积为63.01 m²/g,含有-COOH、-OH等丰富的官能团。在亚甲基蓝初始质量浓度为50 mg/L、初始pH值为11,投加量为2 g/L、25℃吸附120 min时,亚甲基蓝的吸附率可达88.52%,最大吸附量为218.08 mg/g;吸附过程与Langmuir吸附等温模型拟合较好,符合准二级吸附动力学模型。吸附以化学吸附为主,吸附稳定,无二次污染,吸附剂廉价易得,便于分离,是理想的亚甲蓝废水处理试剂。     

氧化铟空心球的合成和光致发光性能研究

在180℃水热处理葡萄糖和铟盐的混合物,然后在空气中烧结制备了氧化铟空心球.利用场发射扫描电镜、透射电镜、X射线衍射等对其形貌和结构进行分析.结果表明,氧化铟空心球为多孔结构,其粒径为800～1000nm,由密堆积的纳米粒子组装而成.讨论了氧化铟空心球的形成机制和光致发光特性.     

Dye adsorption behavior of Luffa cylindrica fibers

Using natural Luffa cylindrica fibers as adsorbent removal of methylene blue dye from aqueous solutions at different temperatures and dye concentrations was investigated in this study. Thermodynamics and kinetics of adsorption were also investigated. The adsorption isotherms could be well defined with Langmuir model instead of Freundlich model. The thermodynamic parameters of methylene blue (MB) adsorption indicated that the adsorption is exothermic and spontaneous. The average MB adsorption capacity was found out as 49 mg/g and average BET surface area of fibers was calculated as 123 m(2)/g.     

磷掺杂中空碳球的制备及其电容性能EI北大核心CSCD

以酚醛预聚体和苯乙烯为原料通过水热法一步合成中空聚合物球(HPS),再以三氯化磷为反应剂通过傅-克反应对HPS处理得到含磷交联聚合物,经高温炭化和KOH活化制备磷掺杂中空碳球(AP-HCS)。采用FT-IR,TG,SEM,TEM,Raman,BET,XPS等手段对含磷聚合物和碳材料的组成、结构与形貌进行表征,测试碳材料在1 mol/L H2SO4介质中的电容性能。结果表明:AP-HCS的比表面积可达2177 m2/g,在1 A/g电流密度下,比电容为288 F/g,5 A/g电流密度下经循环充放电5000次后比电容值仍能保持88.9%,具备良好的电容性能。     

Synthesis and photo-degradation application of WO3/TiO2 hollow spheres

A WO(3)/TiO(2) composite, hollow-sphere photocatalyst with average diameter of 320 nm and shell thickness of 50 nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO(3)/TiO(2) hollow spheres were red-shifted compared to the TiO(2) hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO(3) and TiO(2) phases were confirmed by X-ray diffraction analysis. BET isotherms revealed that the specific surface area and average pore diameter of the hollow spheres were 40.95 m(2)/g and 19 nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO(3)/TiO(2) hollow spheres under visible light within 80 min. Under the same conditions, only 24% MB can be photodegraded by TiO(2). The photocatalytic mineralization of MB, catalyzed by TiO(2) and WO(3)/TiO(2), proceeded at a significantly higher rate under UV irradiation than that under visible light, and more significant was the increase in the apparent rate constant with the WO(3)/TiO(2) composite semiconductor material which was 3.2- and 3.5-fold higher than with the TiO(2) material under both UV and visible light irradiation. The increased photocatalytic activity of the coupled nanocomposites was attributed to photoelectron/hole separation efficiency and the extension of the wavelength range of photoexcitation.     

Applicability of the various adsorption models of three dyes adsorption onto activated carbon prepared waste apricot

In this study, activated carbon (WA11Zn5) was prepared from waste apricot, which is waste in apricot plants in Malatya, by chemical activation with ZnCl(2). BET surface area of activated carbon is determined as 1060 m(2)/g. Activated carbon includes both micro and mesopores. Percentages of micropores and mesopores area are determined 36% and 74%, percentage of micropores and mesopores volume is 19% and 81%, respectively. The ability of WA11Zn5, to remove three dyes, methylene blue (MB), malachite green (MG), and crystal violet (CV), from effluent solutions by adsorption has been studied. The adsorption capacities of WA11Zn5 decreases in the order malachite green (MG)>methylene blue (MB)>crystal violet (CV). Equilibrium isotherms for the adsorption of three dyes on activated carbon were measured experimentally. Results were analyzed by the Langmiur, Freundlich, Dubinin-Redushkevich (D-R), Temkin, Frumkin, Harkins-Jura, Halsey and Henderson equation using linearized correlation coefficient at different temperature. The characteristic parameters for each isotherm have been determined. Models and the isotherm constant were evaluated depending on temperature. Langmiur and Frumkin equation is found to best represent the equilibrium data for three dye-WA11Zn5 systems.