Light energy conversion device for photocatalyst 2.0%WO_3-TiO_2 with oxygen vacancies for water splitting

Using carbon felt,polytetrafluoroethylene latex and powder catalyst to assembly a light energy conversion device,the photocatalytic activity of catalyst 2.0%WO3-TiO2(2%WO3 compounding TiO2) with oxygen vacancies was studied through the water splitting for O2 evolution,using a high pressure mercury lamp as the light source and Fe 3+ as the electron acceptor in two different devices:an ordinary photolysis device with catalyst powder suspending through a magnetic stirrer and a self-assembly light energy conversion device.The results show that after 12 h irradiation,the photocatalytic activity of 2.0%WO3-TiO2 with oxygen vacancies in the self-assembly light energy conversion device is higher than that of the ordinary photolysis device,and the amount of oxygen evolution is about 12 and 9 mmol/L respectively in these two devices.After 12 h,the rates of O2 evolution are slow in each device and the photocatalyst almost loses the photoactivity in the ordinary photolysis device.So,compared with the ordinary photocatalytic device,the rate of oxygen evolution and the life time of the catalyst are improved in the self-assembly light energy conversion device.     

Preparation of TiO2 photocatalyst loaded with V2O5 for O2 evolution

TiO₂ photocatalysts loaded with V₂O₅ were prepared via a modified hydrolysis process, and characterized by X-ray diffraction, transmission electron microscopy, Raman spectra and diffuse reflectance UV-Vis spectra measurements. The photocatalytic activity of V₂O₅/TiO₂ was investigated by employing splitting of water for O₂ evolution. The results indicate that V₂O₅ loading can pronouncedly improve the photocatalytic activity of TiO₂ with Fe³⁺ as an electron acceptor under UV or visible light irradiation. The optimum mass fraction of the loaded V₂O₅ is 8%, and the largest speed of O₂ evolution for 8%V₂O₅ (mass fraction) loaded TiO₂ catalyst is 118.2 μmol/(L·h) under UV irradiation, and 83.7 μmol/(L·h) under visible light irradiation.     

光催化分解水制氢的临界光能转换效率

为了确定在能量转换上有价值的光催化分解水制氢过程,提出了临界光能转换效率的概念。临界光能转换效率就是系统产出的氢能与外界输入系统的能量相等时的光能转换效率。只有当光能转换效率超过其临界光能转换效率的时候才有可能实现系统的能量收益。对使用Na2S/Na2SO3作为牺牲剂的体系进行了分析计算,结果显示在年产2万t氢气规模下,该系统的临界光能转换效率为13%。     

Preparation, characterization and photocatalytic behavior of WO3-TiO2/Nb2O5 catalysts

TiO2/Nb2O5 photocatalyst loaded with WO3 (WO3-TiO2/Nb2O5) was prepared by a modified hydrolysis process, and characterized by X-ray diffractometry, transmission electron microscopy, Raman spectra and UV-Vis diffuse refraction spectroscopy. The photocatalytic activity of WO3-TiO2/Nb2O5 was investigated by employing splitting of water for O2 evolution. The results indicate that WO3 loading can pronouncedly improve the photocatalytic activity of TiO2/Nb2O5 by using Fe3 as an electron acceptor under UV irradiation. The optimum molar fraction of the loaded WO3 is 2%, and the largest speed of O2 evolution for 2% WO3-TiO2/Nb2O5 catalyst is 151.8 μmol/(L·h).     

GNR-TiO_2/g-C_3N_4异质结构的制备及其性能研究

采用二次凝胶-溶胶法和水热法合成了具有光催化效应的GNR-TiO_2/g-C_3N_4异质结构,并对其性能进行了研究.研究结果表明:GNR-TiO_2/g-C_3N_4异质结构表现出强的光催化活性,并在可见光照射下,对有机物亚甲基蓝有良好的催化效果.这主要归因于石墨烯纳米带作为载体,不仅增加了异质结构的比表面积,还使空穴-电子对的再结合率降低.     

氧空穴对二氧化钛/磷酸银光催化活性的影响机制

采用磷酸银与具有可见光吸收能力的TiO_2基光催化剂相复合的方法,对带有氧空穴的二氧化钛(TiO_2-OV)的复合磷酸银光催化材料的性能进行了研究.采用光处理法成功制备出了具有可见光吸收能力的氧空穴二氧化钛材料,利用化学吸附法成功制备出了磷酸银/氧空穴二氧化钛复合光催化剂.透射电镜结果显示,磷酸银纳米颗粒均匀分散于氧空穴二氧化钛表面,形成结构完美的复合光催化剂;光催化降解罗丹明B实验结果表明,所制备的磷酸银/氧空穴二氧化钛复合光催化剂的光催化活性明显优于磷酸银光催化材料.     

高效可见光催化剂g-C_3N_4的制备及其催化性能研究

利用马弗炉在空气氛围下高温分解尿素制备具有高效可见光催化活性的类石墨烯g-C_3N_4光催化剂.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见吸收光谱等手段对样品进行性能表征.研究结果表明,升温速率对所制备的g-C_3N_4的晶型结构有显著影响,在升温速率为2℃/min时,所制备的g-C_3N_4的XRD衍射峰与其标准衍射图谱相一致;保温时问长短对所制备的g-C_3N_4的XRD衍射峰产生影响,保温温度则对其影响不大;最佳的制备条件为升温速率2℃/min,500℃恒温5 h.光催化活性实验表明,所制备的光催化剂g-C_3N_4具有优异的可见光催化活性,在可见光辐射50 min条件下,罗丹明B的降解率可达90%.     

铝电池的开发与应用进展

铝元素在地壳中的储量丰富,来源广泛,并且金属铝的安全性高,在离子电池领域中具有广阔的应用前景.尽管铝金属在离子电池中具有如此诱人的优势,但铝离子电池的能量密度、稳定性以及所使用的电解液安全性和成本依然制约其发展.对铝离子电池的最新工作进行梳理、分析和总结,并进一步探讨其作为新型储能体系的机遇和挑战.主要从正极材料、电解液及铝金属负极3个方面对近期的铝离子电池相关工作进行了总结,为开展高能量密度、高稳定性铝离子电池的研究奠定基础.