以支撐式類囊體膜製備生物陽極與其在可撓式光燃料電池之應用

Abstract

光合作用的起始步驟是將光轉換為在類囊體膜中移動的光電子，透過結合類囊體膜與基材製作生物陽極，該光電子可被提取且其後續應用多元，其中光燃料電池是常見的一個。目前本領域多數研究著重利用各種材料來修飾基材以增加光電流，極少人研究類囊體膜的結構與基材本身對紫外光的吸收會如何影響光電流。本研究透過滲透壓將類囊體膨脹，並將其在電極上鋪成平面支撐式膜來增進光電子在膜與基材間的傳遞。透過螢光影像我們觀察到類囊體透過滲透壓控制成功膨脹，且形成之平面支撐式膜具有高表面積；此外我們利用電化學阻抗譜發現平面支撐式膜製成的生物陽極較以原始類囊體膜製成者具有更小的光電子傳遞障礙，這個結果意味平面支撐式膜可以促進光電子傳遞。此外我們亦將類囊體膜和濺鍍於聚對苯二甲酸乙二酯的氧化銦錫(ITO-PET)或碳紙結合，製作類囊體光燃料電池，並透過測量I-V曲線與功率曲線來了解這些電池的特性，我們發現若電極基材的能隙在紫外光區間，將紫外光濾除可以增進光電流和功率。

Photosynthesis is initiated by the conversion of light to photoelectrons that travel in the thylakoid membrane (TM). By combining the TM and electrode substrates to construct bioanodes, the photoelectrons may be extracted for many applications. To increase the photocurrent collected, most studies in this research field currently focus on the modification of the electrode substrates with various materials. Seldom studies have examined how the physical structure of TM and the UV light absorption of the electrode substrates could affect the photocurrent collection. Here, we improved the transfer of photoelectrons from the TM to the electrode substrates by depositing expanded thylakoids onto a planar supported membrane, denoted by expanded-TM, onto an electrode substrate. Through fluorescence images, we observed that the thylakoids were successfully expanded via osmotic pressure and the expanded-TM possessed high surface area. Moreover, with electrochemical impedance spectroscopy, we found the TM-based bioanode constructed with the expanded-TM showed a lower photoelectron transfer resistance compared to that constructed by depositing natural stacked thylakoids. The result suggests that the expanded-TM could facilitate more photoelectron transfer between the TM and the electrode substrates. In addition, we also integrated TM with tin-doped indium oxide coated polyethylene terephthalate (ITO-PET) or carbon paper (CP) to construct TM-based photo fuel cells and removed UV light during illumination. Through measuring I-V curves and power curves of the TM-based photo fuel cells, we found blocking out the UV light during illumination enhanced photocurrents and thus powers when the electrode substrate has a band gap in the UV region. Part of the results in this thesis is reprinted with permission from Formation of Supported Thylakoid Membrane Bioanodes for Effective Electron Transfer and Stable Photocurrent by Yu-Shan Chang, Hao-Cin Yang, and Ling Chao, ACS Applied Materials & Interfaces 2022 14 (19), 22216-22224. DOI:10.1021/acsami.2c04764. Copyright 2022 American Chemical Society.[1](Article Link: https://pubs.acs.org/articlesonrequest/AOR-3TGFSV3FTNVVQPJJ36M3 )