环境协调型Ce-La/TiO_2复合材料的制备及光-湿-热性能

Preparation of Environment Coordination Ce-La/TiO_2 Composites and Photocatalytic-moisture-heat Properties

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。

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 care 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.