掺铁纳米TiO2的制备及其光催化抗菌性能的研究

采用溶胶-凝胶浸渍提拉法制备出玻璃负载纳米TiO2和掺杂不同量Fe3 的样品。用其处理亚甲基蓝溶液,发现掺杂适量的Fe3 可以有效地提高TiO2的光催化活性,过量掺杂反而降低光催化活性,最佳掺杂量为1%。通过对煅烧温度、煅烧时间和镀膜层数等因数的研究,总结出较优化的制备条件。所制备的掺铁纳米TiO2对大肠杆菌,金黄色葡萄球菌和枯草芽孢杆菌有较强的杀灭作用。用XRD对玻璃负载纳米TiO2薄膜进行了表征。     

Efficient Photocatalytic Nitrogen Fixation: Enhanced Polarization,Activation, and Cleavage by Asymmetrical Electron Donation to NN Bond

Photocatalytic nitrogen (N₂) fixation suffers from low efficiency due to the difficult activation of the strongly nonpolar N?N bond. In this study, a Ru–Co bimetal center is constructed at the interface of Ru/CoS_x with S‐vacancy on graphitic carbon nitride nanosheets (Ru‐Vs‐CoS/CN). Upon adsorption, the two N atoms in N₂ are bridged to the Ru–Co center, and the asymmetrical electron donation from Ru and Co atoms to N₂ adsorbate highly polarized N?N bond to double bond order. The plasmonic electric‐field‐enhancement effect enables the Ru/CoS_x interface to boost the generation of energetic electrons. The Schottky barrier between Ru and CoS_x endows the interface with electron transfer from CoS_x to Ru. The Ru‐end bound N at the Ru–Co center is preferentially hydrogenated. As a result, the Ru‐Vs‐CoS/CN photocatalyst shows an NH₃ production rate of up to 0.438 mmol g^?1 h^?1, reaching a high apparent quantum efficiency of 1.28% at 400 nm and solar‐to‐ammonia efficiency of 0.042% in pure water under AM1.5G light irradiation.     

Optical and Electrical Enhancement of Hydrogen Evolution by MoS2@MoO3 Core–Shell Nanowires with Designed Tunable Plasmon Resonance

The design of transition‐metal chalcogenides (TMCs) photocatalysts for water splitting is highly important, in which both light absorption and interfacial engineering play vital roles in photoexcited electron generation, electron transport, and ultimately speeding up water splitting. To this end, plasmonic metal nanomaterials with surface plasmon resonances are promising candidates. However, it is very difficult to enhance the light absorption and manage the interfacial engineering simultaneously, thus, resulting in suboptimal photocatalytic performance. Here, a doped semiconductor plasmon is proposed to optically and electrically enhance TMCs hydrogen evolution. With the tunability of plasmon resonance in a doped MoO₃ semiconductor via hydrogen reduction, the broadband absorption and good interfacial engineering are simultaneously demonstrated in flexible MoS₂@MoO₃ core–shell nanowire photocatalysts. Better energy‐band alignment with MoS₂ can also be realized, thereby achieving improved photoinduced electron generation. More importantly, the defects at the interface between MoO₃ and MoS₂ are effectively reduced because of precise tunability of plasmon resonance, which enhances electron transport. As a proof of concept, this optimized hybrid nanostructure exhibits outstanding H₂ evolution characteristics (841.4 μmol h^?1 g^?1), excellent stability, and good flexibility. The value is also one of the highest hydrogen evolution activity rates to date among the two dimensional‐layered visible‐light photocatalysts.     

电场辅助TiO2薄膜光催化降解甲基橙的影响

将电场引入到TiO2光催化降解甲基橙反应中,实验讨论了电场对TiO2光催化活性的影响及电场对薄膜最佳光催化活性层数的影响.结果表明:外加电场对光催化反应的影响明显,在外加电压30V时,TiO2光催化降解甲基橙的降解率提高了50%;此外,电场对催化剂TiO的最佳光催化活性层数有一定的影响,最佳光催化活性层数从无电场时的6层变为7层.     

碳纤维负载纳米二氧化钛对空气中微量甲醛的吸附-降解性能研究

采用TiO2溶胶和活性碳纤维(ACF)制备的TiO2／ACF光催化剂吸附-降解空气中微量的甲醛。实验结果表明,在室温和无光照条件下,当甲醛浓度为0．4 mg／m3,流量为2．5 L／min时,ACF对甲醛的饱和净化量为43．8μg／g,净化量大于TiO2／ACF;在紫外光照射下,TiO2／ACF对甲醛具有较优异的光催化降解能力,当催化剂中m(TiO2):m(ACF)=0．082 1时,降解速率为0．150μg／(g·min)。TiO2的负载量对催化剂的表面结构、吸附性能和光催化性能有显著的影响。     

TiO2/GO复合材料的制备及其催化性能研究

采用改进Hummers法制备氧化石墨烯(GO),以钛酸丁酯为钛源,通过溶胶-凝胶法制备TiO2/GO纳米复合光催化剂.利用傅里叶红外光谱(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和X射线能谱(EDS)等对催化剂的结构、组成、形貌和粒径进行表征.将催化剂用于光催化降解甲基橙(MO)溶液,考...     

掺杂锡的纳米二氧化钛光催化降解苯酚的研究

以钛酸丁酯为原料,用溶胶-凝胶(So l-gel)法制备了掺杂锡离子的纳米T iO 2粉末。采用透射电子显微镜和X光衍射仪对粉体的粒径、物相、形貌和热稳定性进行了表征。通过粉体对苯酚的降解情况对其光催化活性进行了测试,结果表明5%Sn4 -T iO 2具有良好的光催化氧化性能。     

掺杂铁的纳米二氧化钛光催化降解邻硝基苯酚的研究

以钛酸丁酯为原料,用溶胶-凝胶(So l-gel)法制备了掺杂铁的纳米T iO2粉末。采用X光衍射仪对粉体的物相进行了表征。样品经500℃焙烧2h后,0.02%(摩尔分数)Fe3 -T iO2纳米粉末为单一的锐钛型结构。通过粉体对邻硝基苯酚的降解情况对其光催化活性进行了测试,结果表明与纯T iO2相比,Fe3 -T iO2的光催化活性有较大提高,当Fe3 的掺入量为摩尔比0.02%时催化活性最高。以高压汞灯为光源,邻硝基苯酚的初始浓度为50m g.L-1、催化剂0.02%(摩尔分数)-T iO2投加量为1.0g.-L 1时,邻硝基苯酚的光催化降解效果最好。     

纳米TiO2光催化降解有机废水及改性研究进展

纳米TiO2是近年来半导体材料用于环保领域中研究最多、最具发展前景的高新技术材料之一.作者介绍了纳米TiO2的光催化机理,并对纳米TiO2在降解有机废水等方面的应用进行了评述,还综述了近年来对纳米TiO2改性方面的研究,包括沉积贵金属、金属离子掺杂、非金属掺杂和半导体复合等技术.     

TiO2-Ce(SO4)2光催化氧化体系-光度法测定化学需氧量

基于纳米TiO2和Ce(Ⅳ)协同光催化氧化作用原理,以TiO2作为光催化剂,Ce(Ⅳ)作为纳米TiO2光生电子的接受体,提高纳米TiO2的光催化氧化能力。通过测定Ce(Ⅳ)的紫外吸光度变化值ΔA,建立了纳米光催化氧化体系测定化学需氧量(COD)的新方法。考察了测定方法的最佳条件,当TiO2的投加质量浓度为4g/L、Ce(Ⅳ)的浓度为6mmol/L,反应温度为45℃、反应液pH为1.2以及反应时间10min时,COD在1.0～10mg/L范围内与Ce(Ⅳ)吸光度变化值ΔA呈线性关系,其相应的线性方程为:ΔA=0.0238COD 0.3072,相关系数R=0.9982,COD的检测限为0.5mg/L。