水热法合成Nd~(3+)掺杂SiO_2介孔分子筛及其发光性能研究

通过水热法合成Nd~(3+)掺杂的介孔分子筛(FDU-12)发光材料,以三嵌段共聚物(F127)作为模板剂,正硅酸乙酯(TEOS)为硅源,氯化铝(AlCl3)为修饰剂,在合成过程中将Nd~(3+)掺杂到FDU-12介孔分子筛中。通过X射线粉末衍射(XRD)、N2的等温吸附-脱附、透射电镜(TEM)和荧光光谱测试等手段对合成的粉体进行表征。结果表明,元素Nd以+3价态存在于FDU-12介孔分子筛中,合成的FDU-12/Nd分子筛具有规则的面心立方孔道结构,以LED激光器808nm对样品进行荧光测试时,其在912,1 065和1 350nm处出现钕离子的特征发射峰,表明FDU-12/Nd介孔分子筛表现出较好的荧光性能,有望成为掺钕激光器或放大器的新型基质材料。     

介孔碳材料对染料大分子的吸附性能研究

采用嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯(PEO-PPO-PEO,F127)和聚二甲基硅氧烷-聚氧乙烯(PDMS-PEO)为混合模板剂制备了有序介孔碳材料,并采用小角X射线散射(SAXS)和氮气吸附/脱附对其结构进行了表征,进一步研究了上述介孔碳材料对甲基橙、亚甲基蓝和碱性品红3种染料大分子的吸附性能。     

活化凹凸棒石合成多级孔钛硅分子筛及其光催化性能研究EI北大核心CSCD

以天然凹凸棒石为硅源,钛酸丁酯为钛源,四丙基氢氧化铵为模板剂一步水热合成钛硅分子筛,并研究了钛硅比对合成产物结构和性能的影响。通过XRD,SEM,UV-Vis和N_(2)吸附-脱附对钛硅分子筛的晶体结构、形貌、钛的存在形式和孔道特征进行表征,并对亚甲基蓝印染废水进行光催化实验考察分子筛的光催化性能。结果表明,当钛硅比为1∶30时,其XRD特征峰强,结晶度高,晶粒大小均匀,呈规则六棱柱状,钛以骨架钛和锐钛矿型TiO_(2)形式存在,孔道结构兼具微孔和介孔。分子筛具有光催化性,光催化反应遵循拟一级反应动力学。利用响应曲面法建立模型优化pH=7.8亚甲基蓝溶液最佳实验条件为初始浓度10.0 g/mL,光催化时间48 min,投加量0.05 g,经光催化降解溶液脱色率达到98.75%。     

酸的种类和浓度对有序介孔二氧化硅形貌和孔结构的影响

以三嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯(PEO-PPO-PEO)为模板剂,正硅酸乙酯为无机硅源,HCl、HNO3、H2SO4及H3PO4四种酸为酸性介质,采用水热法合成有序介孔分子筛SBA-15。通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、N2吸附-脱附等手段对产物的形貌和结构进行分析。结果表明:控制合成母液中H+浓度在一定范围时,HCl、HNO3、H2SO4、H3PO4四种介质中合成出的产品分别为"麦穗"状、"铜钱"状、长程连续"糖块"状和高度分散"糖块"状;在酸种类相同条件下,酸浓度对孔道的大小、微孔含量、孔壁厚度等孔道结构参数有一定影响,但酸浓度对孔道的影响要远小于酸种类的影响。     

介孔分子筛MCM-41的合成方法与晶化条件

介孔材料MCM-41具有规则孔道结构,在多相催化、吸附分离、复合材料、纳米组装等领域有着重要的学术研究与应用价值.其可以通过长链季铵盐、伯胺、双子胺或聚氧乙烯类表面活性剂胶束的模板作用,在多种不同的条件下合成.综述了MCM-41介孔分子筛近年来所取得的进展,介绍和讨论了各种合成工艺方法,归纳和分析了影响其合成的主要因素.     

饱和ATP为原料合成多级孔ZSM-5沸石分子筛的制备与表征

研究以饱和ATP吸附材料为合成沸石分子筛的硅源,采用双模板法,用四丙基氢氧化铵(TPAOH)为微孔模板剂和十六烷基三甲基溴化烷(CTAB)为介孔模板剂直接合成多级孔ZSM-5沸石分子筛,通过XRD、SE M、比表面积及孔径分析仪进行N_2吸附-脱附等手段对多级孔ZSM-5沸石分子筛表征测试分析。结果表明:饱和ATP吸附材料在180℃下,水热提纯12 h获得硅源,再加入TPAOH和CTAB进行初始凝胶反应,后移入水热反应釜中,控温180℃,水热晶化反应15 h,即得多级孔ZSM-5沸石分子筛。     

镧(Ⅲ)对SBA-15分子筛改性研究

借助水热法,利用三嵌段共聚物聚(1,2-亚乙基二醇)-嵌段-聚(丙二醇)-嵌段-聚(1,2-亚乙基二醇)为模板剂,正硅酸四乙酯为硅源,强酸性条件下制备了分子筛SBA-15.分别以水及水+乙醇为介质采用LaCl₃溶液与煅烧的主体材料SBA-15分子筛固-液相交换法,制备了La-(SBA-15)复合材料.利用化学分析、粉末XRD、N₂吸附技术、IR评价了制备方法的有效性及对SBA-15分子筛孔结构的影响.结果表明,镧已并入SBA-15分子筛中,SBA-15内表面上的硅羟基团是镧进入的主要位置,部分客体在分子筛孔道内.制得的材料La-(SBA-15)保持高度有序的介孔二维六角结构,不改变载体SBA-15的介孔孔道结构.此外,考察了La-(SBA-15)产物的发光现象.     

磷酸介质体系中合成Al-SBA-15介孔分子筛的研究(英文)

以正硅酸乙酯为硅源,非离子表面活性剂P123为模板剂,异丙醇铝为铝源,在磷酸介质中合成出了Al-SBA-15介孔分子筛。采用XRD、TEM、SEM、N2-BET、TG-DTA等表征手段,考察了所得材料的物化性能。分析了初始溶液中硅铝比对介观结构的影响。所得材料在XRD谱图中(100)、(110)和(200)处出现较强衍射峰,氮气吸-脱附曲线为典型的Ⅳ型且有H1滞后环,结合TEM分析表明产物具有二维六方排列的介孔结构(空间群为p6mm),SEM结果表明相对纯硅SBA-15,Al-SBA-15介孔分子筛长程有序性没有受到限制。     

复合介孔材料的结构与催化性能

以三嵌段共聚物P123为模板剂、正硅酸乙酯为硅源,在强酸和水热条件下合成了介孔分子筛SBA-15,用胺丙基三乙氧基硅烷对分子筛进行功能化。运用X射线衍射、傅里叶红外光谱,N_2吸附-脱附以及透射电子显微镜等手段对功能化前后的介孔分子筛进行了表征。以甘氨酸法制备草甘膦工艺为模型反应进行的催化性能分析表明:该介孔分子筛对该反应具有较高的催化性能。     

水蒸气诱导自组装制备介-微孔ZSM-5分子筛的研究

软模板剂方法可以合成介-微孔分子筛,但有些模板剂与硅铝酸盐之间弱的化学结合力导致晶化过程模板剂与合成体系的相分离,结果形成了无定型的介孔材料和微孔分子筛的混合物。采用新的技术路线:通过使用四丙基氢氧化铵(TPAOH)作模板剂,以三嵌段共聚物P123原位植入介孔结构,采用水蒸气诱导干凝胶自组装晶化的方法制备介-微孔ZSM-5分子筛。优点是:大大减少了模板剂的使用量,省去了产品与母液分离的繁琐步骤,无大量废液产生,对环境友好。采用X射线衍射 (XRD)、傅立叶变换红外光谱(FT-IR)、N₂吸附-脱附比表面分析(BET)、扫描电镜(SEM)、高倍透射电镜(TEM)系列表征方法对介-微孔ZSM-5分子筛进行表征,可知样品具有典型的ZSM-5分子筛的骨架结构和明显地介孔孔道。在800 ℃,100%水蒸气条件下经15 h水热老化后,分子筛的比表面积保留率73.44%,孔容保留率74.35%,表明分子筛的水热稳定性良好。     

Synthesis and Characterization of Mesoporous Titania Particles and Thin Films

Well-organized mesoporous titania particles and thin films were successfully synthesized by using tetrabutyl titanate as the inorganic precursor and triblock copolymer （Pluronic P123） as the template via evaporationinduced self-assembly process. The resulting materials were characterized by high resolution transmission electron microscopy （HRTEM）, X-ray diffraction （XRD）. Fourier-transform infrared spectroscopy （FT-IR）,Brunauer-Emmett-Teller （BET） and atomic force microscopy （AFM）. Macro shape of mesoporous titania would greatly influence the mesostructure of materials, and the probable reasons were also discussed.     

Synthesis of TiO2 supported on SBA-15 using different method and their photocatalytic activity

SBA-15 mesoporous materials were successfully prepared by the conventional hydrothermal method and TiO2 nanoparticles were supported on them using different loading methods. The synthesized materials were characterized and their activity as photocatalysts for the decomposition of methylene blue was evaluated. The loading of titanium dioxide on the framework of SBA-15 makes the pore diameter and pore volume decrease compared to that of SBA-15. The chelating method causes the support to have a much better dispersion capacity for TiO2 particles as compared to the other two methods. The TiO2 supported by chelating method showed the highest photocatalytic activity among the photocatalysts prepared by different method.     

Characterization and application of Ti-containing mesoporous silica for dye removal with synergistic effect of coupled adsorption and photocatalytic oxidation

Highly ordered mesoporous silica, Santa Barbara Amorphous-15 (SBA-15), and titanium-substituted mesoporous silica (TiSBA-15) materials were successfully synthesized, characterized, and evaluated. The textual and structural properties of the prepared materials with various titanium contents were characterized by inductively coupled plasma-mass spectrometer (ICP-MS), powder X-ray diffraction (XRD) patterns, nitrogen physisorption isotherms, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A limited content of titanium could be effectively substituted into the framework of SBA-15 without provoking structure change. The adsorptive performance was examined by methylene blue (MB) adsorbed on prepared materials. The isotherm models were analyzed to describe the adsorption behavior of prepared materials. The adsorption isotherms were well-fitted with Langmuir and Freundlich models in the simulation of the adsorption behavior of dyes. The SBA-15 and TiSBA-15 materials were found to be effective adsorbents for MB from aqueous solutions. The photodegradation of MB and total organic carbon (TOC) analysis on solid composites were used to evaluate the catalytical performance of Ti-containing mesoporous silica. The synergistic effect of adsorptive and photocatalytical ability of prepared TiSBA-15 was identified. The regeneration and cyclic performance were also proved. These results revealed that TiSBA-15 could be one effective alternative material for dye removal.     

介孔炭作为加氢脱硫催化剂载体材料的研究

以介孔硅SBA-15为模板,焦糖和呋喃醇为碳源,通过多种浇注法制备介孔炭材料.采用低温氮吸附、透射电镜和X射线小角衍射分析模板及介孔炭的织构.结果显示合成的介孔炭成功地复制了SBA-15的结构.以制备的介孔炭作载体担载钴钼合成了加氢脱硫催化剂,利用X射线能谱、透射电镜能量分布谱及一氧化氮化学吸附评估了催化剂的活性及活性点分布,结果表明介孔炭担载的催化剂活性高于活性炭担载的同类催化剂.     

TiO_2纳米颗粒与微米带的制备及催化性能

以钛酸四丁酯为前驱体分别采用溶胶-凝胶法合成TiO2纳米颗粒和模板法合成TiO2微米带,对制备的材料进行差热热重分析、红外光谱、扫描电镜、透射电镜和X射线衍射分析;以甲基橙的脱色降解为模式反应,考察样品的光催化性能。结果表明:以脱脂棉为模板制备出的TiO2微米带,经600℃煅烧,长径比为70,紫外光照射50 min后对甲基橙的催化效率可达90%;600℃煅烧的TiO2纳米颗粒,粒径为80～100 nm,50 min的催化效率仅为75%。     

镧(Ⅲ)对SBA-15分子筛改性研究

借助水热法，利用三嵌段共聚物聚(1，2—亚乙基二醇)—嵌段—聚(丙二醇)—嵌段—聚(1，2—亚乙基二醇)为模板剂，正硅酸四乙酯为硅源，强酸性条件下制备了分子筛SBA—15．分别以水及水 乙醇为介质采用LaCl3溶液与煅烧的主体材料SBA—15分子筛固—液相交换法，制备了La—(SBA—15)复合材料．利用化学分析、粉末XRD、N2吸附技术、IR评价了制备方法的有效性及对SBA—15分子筛孔结构的影响．结果表明，镧已并入SBA—15分子筛中，SBA—15内表面上的硅羟基团是镧进入的主要位置，部分客体在分子筛孔道内．制得的材料La—(SBA—15)保持高度有序的介孔二维六角结构，不改变载体SBA—15的介SLSL道结构．此外，考察了La—(SBA—15)产物的发光现象。     

Synthesis of TiO2 supported on SBA-15 using chelating method and their photocatalytic decomposition of methylene blue

SBA-15 mesoporous materials were successfully prepared by the conventional hydrothermal method and used as the support for TiO2 loaded SBA-15 photocatalysts. The synthesized materials were characterized by XRD, PL, FT-IR, BET and TEM. We also examined the activity of these materials as photocatalysts for the decomposition of methylene blue. The loading of titanium dioxide on the framework of SBA-15 makes the pore diameter and the pore volume decrease and decreases the surface area compared to that of SBA-15. For the TiO2 loaded SBA-15 photocatalysts, the IR absorption at approximately 960 cm(-1) is commonly accepted as the characteristic vibration of the Ti-O-Si bond. The PL peaks appears at about 410 nm at a loading ratio of less than 5% but moves to 430 nm at higher loading ratios. It was also shown that the excitonic PL signal is proportional to the photocatalytic activity for the decomposition of methylene blue. The photocatalytic activity increases with increasing TiO2 loading ratio, shows a maximum value at 7% TiO2/SBA-15, and then decreases at 10% TiO2/SBA-15.     

TiO2@SBA-15的合成及其光解性能

以水热沉积法在介孔SBA-15上固载TiO2纳米粒子制得光催化剂TiO2@SBA-15,探讨了TiO2负载量对催化效果的影响.以包括N2吸附-脱附、紫外漫反射光谱(DRS)等手段在内的多种技术手段表征了催化剂的结构.研究结果表明适宜负载量的锐钛矿晶型TiO2纳米粒子可均匀分散在载体SBA-15上,N2吸附-脱附进一步表明载体介孔结构得以保持.适宜TiO2负载量的催化剂20 mg紫外光照25 min可将100 mL的10 mg·L-1亚甲基蓝降解完全.     

模板法制备介孔TiO2及其光催化性能研究

以十六烷基三甲基溴化铵(CTAB)作为模板剂,钛酸正四丁酯(TBOT)为钛源,异丙醇为溶剂,通过溶胶-凝胶过程合成出介孔TiO2前驱体凝胶后,经老化、焙烧得到了TiO2介孔材料.利用XRD、HR-TEM、TGA、N2的吸附-脱附、BET等方法对材料的结构、形貌、比表面积、孔径分布进行表征.以亚甲基蓝的降解为模型反应,对其催化性能进行评价并与商品DegussaP-25进行比较.实验结果表明,比表面积为137.5m2/g、孔径为8.62nm的锐钛型介孔TiO2具有很高的催化活性.