In this study, the adsorption and photocatalytic degradation performances of a TiO₂/diatomite composite were investigated using ketones and alcohols with different carbon chain lengths as target pollutants. The effects of relative humidity and oxygen on the photocatalytic process of the composite and the different roles of water vapor and oxygen in this process were investigated. The adsorption capacity of VOCs over the composite decreased exponentially with the increase of relative humidity. During the degradation of the ketones and alcohols using the composite, the optimal relative humidity condition for VOC degradation was related to the length of the carbon chain. The optimal relative humidity for acetone, 2-butanone, and 2-heptanone degradation was 5%, 15%, and 30%, respectively. For the tested alcohols, the optimal relative humidity for degradation of isopropanol, isobutanol, and 1-heptanol was 5%, 15%, and 50%, respectively. When dry air was used, a high VOC degradation rate was observed. However, at the optimum relative humidity but in the absence of oxygen, VOC degradation hardly occurred. Compared with water vapor, oxygen played a more important role in the photocatalytic degradation of ketones and alcohols by the TiO₂/diatomite composite.

中文翻译：

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TiO2 /硅藻土复合材料对VOC的集成吸附和光催化降解：相对湿度和反应气氛的影响

在这项研究中，TiO ₂的吸附和光催化降解性能使用具有不同碳链长度的酮和醇作为目标污染物研究了/硅藻土复合材料。研究了相对湿度和氧气对复合材料光催化过程的影响以及水蒸气和氧气在该过程中的不同作用。随着相对湿度的增加，VOCs在复合材料上的吸附能力呈指数下降。在使用复合物降解酮和醇的过程中，VOC降解的最佳相对湿度条件与碳链的长度有关。丙酮，2-丁酮和2-庚酮降解的最佳相对湿度分别为5％，15％和30％。对于测试的醇，异丙醇，异丁醇和1-庚醇降解的最佳相对湿度为5％，15％和50％，分别。当使用干燥空气时，观察到较高的VOC降解速率。但是，在最佳相对湿度下但没有氧气的情况下，VOC几乎不会降解。与水蒸气相比，氧气在二氧化钛光催化降解酮和醇中起着更重要的作用。₂ /硅藻土复合物。