负载型催化剂对风化煤制备腐植酸的影响

以自制碳纳米管(CNTs)为载体,制备了负载型催化剂CeO2/CNTs、TiO2/CNTs和Ce-Ti-Ox/CNTs,并进行了TEM及XRD表征。以所得样品为催化剂用于东都风化煤降解制备腐植酸的研究,探讨了催化剂用量、反应温度及不同负载型催化剂对风化煤降解制备腐植酸的产率、分子结构及吸光度的影响。结果表明,所用负载型催化剂催化性能明显高于未负载的催化剂,能显著提高腐植酸的产率,而且所得腐植酸分子量较小,吸光度较高,其中Ce-Ti-Ox/CNTs催化效果最为显著,可使腐植酸的产率提高到65.43%,表明铈钛活性组分表现出了协同催化效应。     

石墨烯/Ni/TiO_2/CNTs复合物的制备及其光催化性能

首先通过溶剂热法,在石墨烯表面负载掺杂镍的纳米二氧化钛膜,制备石墨烯/Ni/TiO2复合材料;然后以掺杂的镍为催化剂,采用化学气相沉积法,原位生长碳纳米管(CNTs),得到石墨烯/Ni/TiO2/CNTs复合材料。通过XRD、SEM、TEM、拉曼等方法对制备样品的晶型、微观形貌等进行了表征,考察了样品在紫外光及可见光下对甲基橙的光催化降解性能。结果表明:石墨烯和CNTs的加入使得Ni/TiO2、石墨烯/Ni/TiO2、石墨烯/Ni/TiO2/CNTs复合物的光催化活性依次提高,并且石墨烯/Ni/TiO2/CNTs复合物中石墨烯含量越多时,所得复合物的光催化降解性能越好。石墨烯含量最大的石墨烯/Ni/TiO2/CNTs样品,在紫外光下对甲基橙的降解率达到98%,在可见光下的光催化降解效率比掺镍TiO2提高了3.5倍。     

微波辅助加热乙二醇法制备PtSn/CNT催化剂:pH值对其结构和电氧化甲醇性能的影响（英文）

采用微波辅助加热乙二醇法制备了碳纳米管(CNTs)负载的PtSn双组份催化剂。采用原子吸收光谱,X射线衍射仪和电子透射显微镜对产物进行了表征。结果表明,含金属离子前驱体的乙二醇溶液的pH值对产物的金属催化剂负载量、合金化程度和PtSn粒子的形态有显著的影响。在pH值为5时能得到组分配比为原始设计值的PtSn/CNT催化剂。在pH值2~7的范围内纳米粒子的尺寸较小,随着pH值的进一步提高,纳米粒子直径变大且发生团聚。电化学测试表明在pH值为5时得到的PtSn/CNT催化剂对甲醇电化学氧化具有最佳的催化作用。合适的金属负载比例和良好的纳米颗粒形状和尺寸分布控制是得到优异的催化性能的主要原因。     

锌卟啉敏化TiO2光催化剂的原位法制备及其光催化性能研究

以锌卟啉为敏化剂,采用溶剂热法原位合成了锌卟啉敏化TiO2复合光催化剂。利用XRD、SEM、UV-Vis DRS和TG-DTA对所得锌卟啉-TiO2复合光催化剂进行了表征和分析。分析结果表明,采用原位合成法能使锌卟啉原位负载于TiO2表面,且未改变TiO2的晶型和形貌;锌卟啉的存在使TiO2在可见光区域出现吸收峰,采用原位合成法制备的金属卟啉敏化TiO2光催化剂相对于溶剂回流法制备金属卟啉敏化TiO2光催化剂有更好的热稳定性和更好的催化降解亚甲基蓝性能。     

CNT-TiO2复合物的制备及其乳液催化苯甲醇选择氧化

以CNTs为基质,钛酸异丙酯为钛源,采用水热法制备CNT-TiO2复合物。采用扫描电子显微镜和X射线衍射等技术手段研究CNT-TiO2复合物的形貌和晶型结构特征,通过光学显微镜等技术手段研究TiO2、CNT-TiO2固体纳米颗粒形成的乳液体系的特征。以苯甲醇选择氧化制备苯甲醛为探针反应,研究浸渍法所制负载型钌基TiO2、CNT-TiO2乳液催化剂的催化反应性能,催化剂载体的乳化能力与其催化性能之间的规律性关系。结果发现:CNT-TiO2复合物的乳化能力强于TiO2颗粒,易形成乳液体积大及乳滴分布均匀的乳液体系;负载型Ru/CNT-TiO2催化剂的催化活性高于Ru/TiO2;催化剂载体的乳化能力与其催化活性密切相关,载体的乳化能力越强催化活性越高;CNT-TiO2复合物在苯甲醇选择氧化反应体系中起到了催化剂载体和固体乳化剂的双重作用。     

铜/碳纳米管复合粒子的制备及其对高氯酸铵热分解性能研究

以碳纳米管为载体, 用化学沉积法制备了Cu/CNTs复合粒子, 并用TEM、SEM、FT-IR、XRD、XPS和DTA对其表观形貌、结构及催化性能进行了表征. 结果表明, CNTs和Cu之间无论是简单混合还是复合, 对高氯酸铵(AP)的热分解均有催化作用. 与纯AP相比, Cu/CNTs复合粒子中的AP高温分解峰温降低126.3℃, 低温分解峰几乎消失, 表观分解热由309.92J/g提高到711.13J/g; 与简单混合物相比, 复合粒子中的AP高温分解峰温降低11.4℃, 表观分解热由494.06J/g提高到711.13J/g. 表明CNTs与Cu的复合处理可显著提高其对AP热分解反应的催化作用.     

纳米TiO2-CeO2复合紫外屏蔽剂的制备和性能研究

采用溶胶凝胶法制备纳米TiO2，CeO2粉体，纳米TiO2-CeO2复合材料。并对其单一粉体和复合粉体的紫外吸收性能加以研究。分析了不同的铈钛比例和复合方式对其复合材料的颗粒形状，粒径大小以及紫外屏蔽效果的影响。研究结果表明采用溶胶凝胶法可制备粒径〈100nm的TiO2、CeO2以及TiO2．CeO2复合粉体。TiO2-CeO2复合粉体的紫外屏蔽效果优于纳米TiO2、CeO2的单一粉体．采用TiO2溶胶与CeO2溶胶混合制备的TiO2-CeO2复合粉体的紫外吸收性较好，该复合粉体中铈钛比例为1：3。     

P(MMA-AN)/TiO2复合粒子的制备及光催化性能

采用原位乳液聚合方法制备了基于共价键结合的P(MMA-AN)/TiO2复合粒子,红外光谱和热失重分析结果表明P(MMA-AN)在TiO2表面接枝率为15.9%。以甲基橙溶液为目标污染物,研究了P(MMA-AN)/TiO2复合粒子和TiO2对甲基橙的吸附和光催化降解甲基橙溶液的性能,结果表明:两种粒子对甲基橙的吸附都很少;在相同时间内,P(MMA-AN)/TiO2复合粒子对甲基橙溶液的降解性能优于TiO2,紫外光照180 min后,P(MMA-AN)/TiO2复合粒子对甲基橙溶液的降解率达到了88%,而TiO2仅为74%。     

单分散纳米CeO_2和Cu-Ce-O催化剂的制备、表征及其催化性能

以硝酸铈、硝酸铜和氢氧化钠为原料,使用超声双雾化工艺实现微区反应制备了纳米CeO2粉体和掺铜CeO2复合粉体,并利用XRD、TEM、HR-TEM、FT-IR和BETN2等手段对其成分、物相结构、形貌及颗粒大小进行表征;并将所制备的粉体作为催化剂考察其对CO的催化氧化性能.结果表明,所制备的纳米CeO2粉体和掺铜CeO2复合粉体粒径均为4～5 nm,球形,粒度分布均匀,且单分散性好;CeO2催化剂粉体粒径越小、比表面积越大,对CO的催化氧化活性越高;Cu-Ce-O催化荆对CO具有最好的催化氧化活性,表明铜的掺入有利于明显提高CeO2催化剂在CO催化氧化反应中的低温活性,降低起燃温度.     

TiO_2/ZnO纳米管的制备及其光催化性能

采用电化学阳极氧化法制备了高度有序的TiO2纳米管阵列,并利用纳米管的光致超亲水特性,采用斜面毛细组装技术在无定形TiO2表面自组装ZnO溶胶后退火制备了TiO2/ZnO复合纳米管.探讨了阳极氧化各参数对纳米管形貌的影响.利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)等方法对样品的结构和形貌进行了表征.以有机磷农药氯胺磷为光催化降解对象,研究了焙烧温度、管径、管长和TiO2/ZnO复合比例等因素对降解效果的影响.结果表明,焙烧温度、管径以及ZnO复合比例对光催化降解率影响较大.对于管径97 nm、管长315.8nm的TiO2/ZnO纳米管,ZnO最佳复合比例为4.2%(质量分数),5 h后降解率达到78%.     

ZnS在TiO2纳米管上的分散对其光催化降解染料废水的影响

水热法制备了TiO2纳米管,并采用简单加热回流的方法制备了ZnS/TiO2纳米复合材料。采用TEM、XRD分析手段对产物进行表征,并对其光催化降解酸性玫瑰红B(AR)染料废水进行了研究。考察了反应物供给速率、硫化锌复合量、催化剂稳定性、光照对光催化降解效果的影响。研究表明控制反应物供给速率和硫化锌的负载量可使硫化锌在二氧化钛纳米管表面均匀分散。当染料废水初始浓度为10mg/L,ZnS:TiO2=8:1时,ZnS/TiO2复合材料光催化活性最高。且催化剂稳定性较好。     

复合纳米TiO2-CeO2的制备及其紫外屏蔽性能

采用直接沉淀法制备了TiO2-CeO2纳米复合氧化物,分析了不同铈钛摩尔比、pH和不同反应温度对合成复合氧化物及其紫外屏蔽效果的影响。研究结果表明,采用直接沉淀法制得了面心立方结构CeO2和锐钛矿型的TiO2混合物,铈钛摩尔比为0.4时复合氧化物在250～450nm波段之间有良好的紫外屏蔽性能。     

TiO2 hydrosols with high activity for photocatalytic degradation of formaldehyde in a gaseous phase

Two types of TiO2 hydrosols (TOSO and HTO) were prepared from titanium sulfate (TiOSO4) and metatitanic acid (H2TiO3) by a chemical precipitation-peptization method, respectively. The prepared hydrosols were characterized by means of X-ray diffraction, particle size distribution, scanning electron microscopy, UV-vis spectroscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller and Barret-Joyner-Halender methods. The results showed that the TiO2 hydrosols with an anatase crystal structure had smaller particle sizes, higher surface areas, larger pore volume, and higher transparence than Degussa P-25 suspension. The photocatalytic activity of the TiO2 hydrosols was evaluated for formaldehyde degradation under UVA illumination in a gaseous phase. The results demonstrated that the photocatalytic activity with the catalyst loading of 2mgcm(-2) was ranked as an order of HTO>TOSO>P-25. The photocatalytic activity was further studied using the HTO catalyst under different experimental conditions. The results showed that catalyst loading, relative humidity, and initial concentration could influence the efficiency of HCHO photocatalytic degradation. It was found that a catalyst loading of more than 2mgcm(-2) and a relative humidity of 55% were two essential conditions for achieving the best performance under these experimental conditions. The repeated experiments indicated that the HTO catalyst was reasonably stable and could be repeatedly used for the HCHO oxidation under UVA irradiation. This investigation would be helpful to promote the application of TiO2 photocatalytic technique for indoor air purification.     

浮动催化CVD法CNTs膜及CNTs膜/环氧复合材料拉伸特性

针对浮动催化化学气相沉积(CVD)法制备的碳纳米管(CNTs)膜,首先采用红外光谱表征分析了包覆在CNTs表面的无定形物质的组成,然后分别采用热处理和酸洗处理方法,考察了CNTs膜中无定形物和残留Fe催化剂对CNTs膜拉伸取向行为的影响。结果表明:采用CVD法制备的CNTs膜中CNTs表面无定形物为含氧或烷烃、烯烃类低聚物,可通过350℃有氧热处理基本去除。该CNTs膜的牵伸取向重排行为受组成影响显著,CNTs表面的低聚物可增强CNTs的管间黏结作用,Fe催化剂颗粒成为CNTs网络结构的交联结点,两者均有利于提高CNTs的取向程度和聚并成束的尺寸,进而提高CNTs膜的拉伸稳定性和断裂韧性。牵伸取向后CNTs膜与环氧树脂溶液的浸润性提高,其CNTs膜/环氧复合材料的拉伸强度和模量达到1228MPa和94.5GPa,相比初始无规CNTs膜/环氧复合材料的分别提高了337%和729%。      

Physical properties and characterization of biodegradable films using nano-sized TiO2/poly(acrylamide-co-methyl methacrylate) composite

In this study, biodegradable films were prepared by using corn starch, PVA, nano-sized poly(acrylamide-co-methyl methacrylate) (PAAm-co-MMA), nano-sized TiO2(P-25)/PAAm-co-MMA composite, and additives which are harmless to the human body, that is, glycerol (GL) and citric acid (CA). Nano-sized PAAm-co-MMA was synthesized by the method of emulsion polymerization. Also, nano-sized TiO2/PAAm-co-MMA composites were synthesized by wet milling for 48 h. The morphology and crystallinty of nano-sized PAAm-co-MMA and TiO2/PAAm-co-MMA composite was observed by the SEM and XRD. The physical properties such as tensile strength (TS), elongation at break (%E), degree of swelling (DS), and solubility (S) of biodegradable films were investigated. The photocatalytic degradability of starch/PVA/nano-sized TiO2/PAAm-co-MMA composite blended films was evaluated using methylene blue as photodegradation target.     

碳纳米管/羟基磷灰石复合材料的制备及表征

以含钴介孔分子筛为催化剂、乙醇为碳源, 采用CVD法制备碳纳米管(CNTs)。通过原位合成法制备一系列不同碳纳米管含量的碳纳米管/羟基磷灰石(CNTs/HA)复合材料。分别采用XRD、FTIR、TEM、N₂吸附-脱附和Raman光谱等分析手段, 对所合成CNTs/HA复合材料的晶相、结构、形貌和比表面积等进行了表征。同时研究了碳纳米管的添加量对所合成CNTs/HA复合材料形貌的影响。XRD与Raman结果表明, 所得CNTs/HA复合粉体中仅有CNTs与HA两种物相, 纯度较高, 结晶度较好; TEM结果显示, CNTs/HA复合材料中CNTs表面均匀包裹着一层纳米级的针状HA晶粒, 两者形成了较强的界面结合, 且当CNTs与HA的质量比为3:17时, CNTs与HA形成最佳结合状态; N₂吸附-脱附表征结果表明, 与HA的比表面积相比, CNTs/HA复合材料具有较高比表面积。     

稀土元素镧与铈对VOx／TiO2催化降解氯苯性能的影响

采用等体积浸渍法分别制备了不同稀土元素@阑或铈）添加量的VOx／TiO催化剂,通过XRD、EDS和TPR对样品进行表征,考察了它们催化燃烧氯苯的活性,结果表明,不同镧或铈添加量的催化剂样品仍保持TiO2税钛矿晶相。当LaOx与VOx的摩尔比为1：5时,会出现镧钒氧物种或镧钛氧物种的晶相;当CeOx与VOx的摩尔比为1．5时,会出现CeOx方铈矿萤石结构的晶相;镧和铈的添加会提高活性物种VOx在催化剂表面的含量和分数}生。当CeOx与VOx的摩尔比为1：13．7时,活性组分VOx绝大部分分布在载体表面;镧对于催化剂的氧化性能没有影响,而铈能提高催化剂的氧化性;适量镧或铈的添加对于VO／TiO2催化剂催化降解氯苯有促进作用。锏的添加对于催化剂催化活性的促进作用与催化剂表面活性物VOx含量有关,而铈的添加对催化剂催化活性的提高作用除此原因外,还与催化剂氧化洼的提高有关。     

Catalytic combustion of ethyl acetate on supported copper oxide catalysts

Total oxidation of ethyl acetate on supported copper oxide catalysts was investigated. The catalysts have been prepared by wet impregnation method and characterized by XRD, TEM and XPS. Among the catalysts with the supports of TiO2, CeO2/TiO2 and CeO2-ZrO2/TiO2, CeO2-ZrO2 solid solutions doped TiO2 supported catalyst gives the highest catalytic activity. Catalyst with the composition of 5 wt.% CuO/10 wt.% CeO2-ZrO2-TiO2 shows the total oxidation of ethyl acetate at about 270 degrees C with the 100% CO2 selectivity. The characterization studies of supported copper oxide catalysts showed that the highly dispersed CuO is one of the active phase which contacts intimately with the support, the action of the interface between the components was not be ignored.     

Photocatalytic degradation of gaseous benzene over TiO2/Sr2CeO4: preparation and photocatalytic behavior of TiO2/Sr2CeO4

The paper demonstrates that the photocatalytic activity of TiO(2) towards the decomposition of gaseous benzene in a batch reactor can be greatly improved by loading TiO(2) on the surface of Sr(2)CeO(4). The research investigates the optimum loading amount of TiO(2) on Sr(2)CeO(4) in enhancing the photocatalytic activity of TiO(2). The prepared photocatalyst was characterized by XRD, UV-vis diffuse reflectance and XPS analyses. TiO(2) is loaded on Sr(2)CeO(4) at 773K. TiO(2)/Sr(2)CeO(4) absorbs much more visible light than TiO(2). The XPS spectrum shows that there are Ti, O, C, Sr elements on the surface of the TiO(2)/Sr(2)CeO(4), and that the binding energy value of Ti2p transfers to a lower value. TiO(2)/Sr(2)CeO(4) demonstrates 2.0 times the photocatalytic activity of pure TiO(2). Based upon these observations, the mechanistic role of Sr(2)CeO(4) in the photocatalytic oxidation reaction has been suggested.