【作者】 张博；

【导师】 张文魁；

【作者基本信息】 浙江工业大学 ， 应用电化学， 2004， 硕士

【摘要】 本工作选择半导体光催化剂TiO₂和SrTiO₃作为研究对象，主要研究了TiO₂和SrTiO₃的制备及其在光充电储氢合金电极中的应用。 本工作首先研究了采用溶胶—凝胶法制备纳米TiO₂时酸催化剂、水、无水乙醇加入量对溶胶胶凝时间的影响，并对原因进行了解释。不添加HNO₃时Ti（OBuⁿ）₄直接水解873K下热处理1h，可得到粒径分布均匀、基本上呈球状的纳米TiO₂粉末，添加HNO₃有利于降低相转变温度和缩小两相共存的温度范围。在本实验范围内，起决定胶凝时间作用的主要因素是体系的粘度，水加入量增加大大延长了胶凝时间，同时水加入量不同会影响相变终止温度，且由于锐钛矿和金红石两相的热焓值相差较小而不存在明显的相转变温度。 研究表明：物理掺杂TiO₂的储氢合金电极不具有光充电性能。PHSA TOhd电极光充电6h后以6mA／g的电流放电时最大容量为14.6mAh／g，充电终止电位最负可达-0.89V（vs.Hg／HgO／6M KOH）。光充电7h后PHSA STO973电极电位能负移至-0.904V，以6mA／g电流放电时其初次容量为5mAh／g。光充电过程可以由两种机理来解释，即光电催化储氢机理和光催化储氢机理。表面覆有TiO₂和SrTiO₃的储氢合金电极均具有可光充电性能。更多还原

【Abstract】 The preparation of semiconductor photocatalysts, including TiO2 and SrTiO3, and their applications in photochargeable HSA electrodes have been investigated in this paper.At first, for the sol-gel method, the effects of the amount of acid catalyst, water and free alcohol in the solution on the time span from sol to gel have been studied, and the reasons have been explained as well. When the precursor was prepared by direct hydrolysis of Ti(OBun)4 without the addition of HNO3 then heat-treatment at 873 K for Ih, the as-prepared spherical TiO2 powder gives the relative uniform size distribution. The addition of HNO3 into solution can finally reduce the temperature of the phase transformation from anatase to rutile and shrink the temperature range of co-existence of two phases. The major factor determining the time span from sol to gel is the viscosity of the system, so the increase in the amount of water can increase the time span from sol to gel and the terminated temperature of phase transformation. The little difference of enthalpy between anatase and rutile phase makes the temperature of phase transformation unnoticeable.The experimental results showed that HSA electrodes mixed physically with TiO2 have no apparent photochargeable properties. The maximum discharge capacity of PHSA TOhd electrode is 14.6mAh/g at the discharge current of 6mA/g after photocharging for 6h, and the corresponding final photocharging potential is up to -0.89V(vs.Hg/HgO/6M KOH). Final photocharging potential of PHSA STO973 electrode after photocharging for 7h is up to -0.904V, and its first capacity is 5mAh/g at the discharge current of 6mA/g . The photocharging process can be explained by two kind of mechanisms, namely photoelectrocatalytic hydrogen storage mechanism and photocatalytic hydrogen storage mechanism. HSA electrodes modified with and SrTiO3 photocatalysts exhibit the obvious photochargeability.更多还原