Liu Shaohua, Zhao Zhihuan, Wang Zhizhong
College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Shanxi 030024.
Photochem Photobiol Sci. 2007 Jun;6(6):695-700. doi: 10.1039/b613098d. Epub 2007 Apr 4.
CoPc loaded titania was synthesized by an improved sol-gel method using a homogeneous hydrolysis technique. The grain size of TiO2 and CoPc-TiO2 was uniform and average diameters were less than 20 nm. Both catalysts had two crystal phases, of which rutile accounted for about 28%. When they were used for the photoreduction of CO2 in NaOH solution under ambient conditions, the formate yield was significantly higher than that of the others, such as formaldehyde, methanol and so on. In order to increase the activity of the photocatalysts some factors were optimized, including the quantity of CoPc-TiO2 catalyst, concentration of Na(2)SO(3) hole scavenger, concentration of the NaOH solution and irradiation time. Under the optimal conditions, the gross photocatalytic reduction of CO2 was 1032 micromol (g cat)(-1). Furthermore, the yield of CH4 did not increase in the presence of CH(3)OH or HCHO, showing that the generation of CH4 from CO2 did not proceed via methanol as an intermediate under these conditions.
采用改进的溶胶 - 凝胶法并运用均相水解技术合成了负载酞菁钴的二氧化钛。TiO₂ 和 CoPc - TiO₂ 的晶粒尺寸均匀，平均直径小于 20 nm。两种催化剂均有两种晶相，其中金红石相约占 28%。当它们在环境条件下用于 NaOH 溶液中 CO₂ 的光还原时，甲酸盐产率显著高于其他产物，如甲醛、甲醇等。为提高光催化剂的活性，对一些因素进行了优化，包括 CoPc - TiO₂ 催化剂的用量、Na₂SO₃ 空穴清除剂的浓度、NaOH 溶液的浓度以及照射时间。在最佳条件下，CO₂ 的总光催化还原量为 1032 μmol (g cat)⁻¹。此外，在 CH₃OH 或 HCHO 存在的情况下，CH₄ 的产率并未增加，这表明在这些条件下，由 CO₂ 生成 CH₄ 并非通过甲醇作为中间体进行。
