Fossil fuels are running out because of human activities, and consumption of fossil fuels increases concentration of carbon dioxide that causes global warming. Therefore, developing a new renewable energy is needed. Microbial fuel cells (MFCs) are eco-friendly technology that can treat wastewater and generate bioelectricity at the same time. But there are some limitations such as low power output and expensive material cost. Thus, this study was conducted to overcome low efficiency of MFCs by developing a new solar hybrid system and current collector that can reduce internal resistance of MFCs. First, suitable photoactive material must be used to harvest sunlight. In this study, N-doped TiO2 nanotubes were used as photoanodes because of their photostability, high electron transfer ability and broad absorption range. Additional electrons are generated from photoanode by light irradiation and it increased power output around 34.9 % compared with a normal MFC reactor. Second, the effect of current collectors was investigated. Current collector must have corrosion resistance in the aqueous solution. Therefore, titanium and stainless steel were used. Graphene oxide is coated on the current collector surface because of its excellent mobility of charge carriers, a large specific surface and good mechanical stability. The highest voltage was generated from the reactor which nanostructured stainless steel 304 mesh was used (452 mV). ⓒ 2015 DGIST
Table Of Contents
I. Introduction 2-- 1. Research Background 2-- 2. Electron Transfer Mechanism 3-- 3. References 5 -- II. Equipment 7 -- 1. Field Emission Scanning Electron Microscope (FE-SEM) 7-- 2. Potentiostat 8 -- 3. X-ray Photoelectron Spectrometer (XPS) 9 -- 4. X-ray Diffractometer (XRD) 10 -- 5. References 12-- III. Investigation of N-doped Titanium Dioxide Nanotubes for The System of Hybrid Solar Microbial Fuel Cell 13-- 1. Introduction 13 -- 2. Experimental Section 14-- 2.1 Materials 14 -- 2.2 MFC set-up 15-- 2.3 Inoculum, substrate and medium 16-- 2.4 Photoanode preparation 16 -- 2.5 Operating procedures 16-- 2.6 Preparation of SEM samples 17-- 2.7 Analysis17 -- 3. Results and Discussion 18-- 3.1 FE-SEM Analysis of Photoanode and Microorganisms on the Anode Surface 18-- 3.2 XRD patterns of photoanode 19-- 3.3 XPS analysis of photoanode 20 -- 3.4 Photocurrent measurement of photoanode 22-- 3.5 Polarization and Power density curves of SMFC 22 -- 4. Conclusions 23 -- 5. References 25 -- IV. Investigation of Current Collectors with Graphene Oxide Coating for Enhance Microbial Fuel Cells Performance 27 -- 1. Introduction 27 -- 2. Experimental Section 28 -- 2.1 Materials 28-- 2.2 Electrical anodization of titanium mesh and stainless steel 304 mesh current collectors 28 -- 2.3 Preparation of graphene oxide coated current collectors 28 -- 2.4 Inoculum, substrate and medium 29-- 2.5 MFC set-up 29 -- 2.6 Analysis 29 -- 3. Results and Discussion 29 -- 3.1 SEM images of normal and graphene oxide coated current collectors 29 -- 3.2 Voltage generation patterns of various microbial fuel cells 31 -- 4. Conclusions 32 -- 5. References 33 -- V. Conclusions 35
Research Interests
CO2 conversion to hydrocarbon fuels; Water splitting for hydrogen generation; Quantum dot devices; Dye sensitized solar cells; Environmental remediation; Synthesis of functional nanomaterials; CO2 연료전환; 수소생산을 위한 광전기화학적 물분해; 양자점 태양전지; 염료감응 태양전지; 공해물질 저감연구; 기능성 나노소재 개발