共軛高分子的分子量及親水性質對光催化產氫反應之影響

Abstract

於此篇論文中，我們將產氫反應後之溶液以電噴灑離子式質譜進行分析並結合密度泛函理論計算探討三乙胺做為犧牲試劑時，於整個產氫系統中所扮演的角色並同時發現其可能具有抑制雙氧水的功用，並且我們也於共軛高分子聚對亞苯 (PPP)的側鏈上引入親疏水基團分別為PHOB以及PPESO3探討親水性質對於產氫的影響，並發現引入親油基團的PHOB會失去產氫的活性，且親水性很好但主鏈上接有三鍵的PPESO3也會失去產氫活性，除了親水性質以外，我們也合成了4個不同分子量的高分子PFBT，並發現聚合度最高也就是分子量最大的PFBT同時也具有最高的產氫效率，並針對這個發現透過一系列的儀器分析來探討其原因。

In this thesis, a solution containing water, triethylamine, methanol, and poly(p-phenylene subsequent to photo-induced hydrogen evolution reaction was examined by electrospray ionization mass spectrometry. Products resulted from triethylamine were detected. Density functional theory calculations were then employed to account for the role of triethylamine in the reaction. The results suggest that triethylamine could not only reduce the activation energy for photo-induced hydrogen evolution reactions but also quench hydrogen peroxide, a side product from the reactions. Hydrophilic and hydrophobic groups are used as the side chains to give conjugated polymers PPESO3 and PHOB, respectively. Impact of hydrophilic properties on hydrogen evolution reactions was discussed. We found that PHOB equipped with hydrophobic group lost the hydrogen evolution activity and PPESO3 with good hydrophilicity was also inactive. The poor catalytic performance of PHOB and PPESO3 might be associated with the strong charge recombination. Moreover, PFBT was synthesized with 4 different molecular weights. It was found that the polymer with the highest molecular weight exhibited the best hydrogen evolution rate. Numerous techniques were utilized to account for the observed efficiency.