环境协调型Ce-La/TiO_2复合材料的制备及光-湿-热性能

采用均匀设计和多元非线性回归方程研究Ce-La掺量(Ce-La与钛酸丁酯的摩尔比)、Ce与La摩尔比、煅烧温度和硅酸四乙酯用量(硅酸四乙酯与钛酸丁酯的体积比)对Ce-La/TiO_2空心微球的吸放湿性能和光催化性能的影响,以确定优化Ce-La/TiO_2空心微球制备参数。将癸酸-棕榈酸采用真空吸附法压入优化Ce-La/TiO_2空心微球的空腔中,制备环境协调型Ce-La/TiO_2复合材料,分析Ce-La/TiO_2复合材料的光-湿-热性能,利用扫描电镜(SEM)与激光粒度仪(LPSA)表征微观形貌与粒径分布。结果表明:4个因素均对Ce-La/TiO_2空心微球的吸放湿性能和光催化性能有影响,其影响显著性为:Ce-La掺量硅酸四乙酯用量Ce与La物质的量比煅烧温度;优化制备工艺参数为Ce-La掺量为0.76%、Ce与La物质的量比为1.0、煅烧温度为646℃、硅酸四乙酯用量为0.63;Ce-La/TiO_2复合材料具有优良的吸放湿性能、光催化性能和相变调温性能,即在相对湿度43.16%~75.29%间的湿容量为0.0576g/g,经过5h的甲醛降解效率为56.37%,从30~15℃降温所需要的时间近500s,具有明显且持续的相变平台。

Preparation of Environment Coordination Ce-La/TiO2 Composites and Photocatalytic-moisture-heat Properties

The uniform experiment design and multivariate nonlinear regression equation were adopted to study the effect of Ce-La dosage(the mole ratio of Ce-La to tetrabutyl titanate),the mole ratio of Ce to La,calcination temperature,and amount of tetraethyl orthosilicate(the volume ratio of tetra-ethyl orthosilicate to tetrabutyl titanate)on the moisture absorption-desorption and photocatalytic properties of Ce-La/TiO2 hollow microspheres,so as to ensure the optimal preparation parameters of Ce-La/TiO2 hollow microspheres.Then,the decanoic-palmitic acid were pressed into the cavity of the optimal Ce-La/TiO2 hollow microspheres by vacuum absorption to prepare environment coordination Ce-La/TiO2 composite materials and analyze the photocatalytic-mositure-heat properties.The scan-ning electron microscopy and laser particle size analyzer were used to characterize the microscopic mor-phology and particle size distribution.The results show that the four factors all have effect on the moisture absorption-desorption and photocatalytic properties of Ce-La/TiO2 hollow microspheres,pri-mary and secondary sequence of each factor is Ce-La dosage>amount of tetraethyl orthosilicate>the mole ratio of Ce to La>calcination temperature.The optimization program is Ce-La dosage 0.76%,the mole ratio of Ce to La is 1.0,calcination temperature 646℃,and amount of tetraethyl orthosili-cate 0.63.The Ce-La/TiO2 composites have good moisture absorption-desorption,photocatalytic and phase changing temperature-adjusting properties.Under 43.16%-75.29%relative humidity,the equi-librium humidity content reaches 0.0576g/g,the degradation rate to formaldehyde reaches 56.37%af-ter 5h,the cooling time lasting nearly 500s during 30-15℃,so the Ce-La/TiO2 composites have re-markable and sustainable phase changing platform.