臺灣博碩士論文加值系統

因為擁有落在可見光區域的狹窄能隙，CuFeO2被認為是適合當作光催化劑的材料。同時，因為合適的能帶位置，CuFeO2也被認為是水裂解中有競爭力的光電陰極候選。
然而，只有少數的研究在探討藉由水熱法製備CuFeO2薄膜，其相關的物理及化學性質仍未明瞭。根據文獻，CuFeO2粉末可以在極高鹼性的環境下以的形式藉由水熱法被合成出來，然而，由於對基板的腐蝕，這種環境不適合用來在透明導電基板上製備CuFeO2薄膜。在我們最近的研究裡改變不同的沉積參數，藉由晶種層的輔助成功在摻氟氧化錫基板(FTO)上製備CuFeO2薄膜。XRD跟SEM的結果顯示CuFeO2 薄膜能夠成功藉由晶種層而生長在FTO上。而SEM則更進一步確認CuFeO2的表面形貌及均勻度。XPS用來分析CuFeO2薄膜中的成份及其氧化態數。UPS及UV-vis用來研究CuFeO2薄膜的光學性質及價帶結構。
此外，CuFeO2的光觸媒性質，包括亞甲基藍的光降解和光催化裂解水也被探討。生長在由滴落塗佈法製備的種子層上的CuFeO2薄膜的光降解速率大約為6.7*10-3/min。相關的光電流在光源的照射下有明顯的增強，其中施加電壓的光子對電流的轉換效率大約為0.501%，在-0.75伏特的位置。

CuFeO2 is a suitable photocatalytic material owing to its narrow band gap in the visible light region. Moreover, CuFeO2 also has a suitable band positions as a photocathode for photoelectrochemical (PEC) water splitting.
However, few studies have focused on fabricating CuFeO2 thin films by a hydrothermal method, and the associated physical and chemical properties are still yet to be extensively studied. From the literature, CuFeO2 powders were synthesized in highly basic conditions by hydrothermal methods, however, the condition was not suitable for fabricating CuFeO2 thin films on transparent conducting substrates. In the current study, CuFeO2 thin films were successfully fabricated on the fluorine doped tin oxide (FTO) substrates with the assistance of a seed layer, which was tailored by tuning various deposition parameters. The XRD and SEM results showed the growth of CuFeO2 films. on FTO substrates. The SEM images also ascertained the morphology and uniformity of CuFeO2 films. The XPS was used to determine the constituent elements and chemical states of CuFeO2. The UPS and UV-vis were used to investigate the optical property and band structure of CuFeO2 films.
In addition, the photocatalytic activities of CuFeO2 films were studied, including photodegradation of methylene blue dye and PEC water splitting. The CuFeO2 films based on drop casting seed layers exhibited the photodegradation rate constant k of approximately 6.7*10-3/min. The associated photocurrent density was enhanced under illumination, and the measured applied bias photon-to-current conversion efficiency (ABPE) was approximately 0.501 % at applied bias at -0.75 V.

CONTENT I
FIGURE CONTENT III
CHAPTER 1 INTRODUCTION 1
1.1 ENERGY SUSTAINABILITY 1
1.2 PHOTOCATALYSIS 2
1.2.1 PHOTOELECTROCHEMICAL (PEC) WATER SPLITTING 2
1.2.2 PHOTODEGRADATION 8
1.2.3 STRATEGIES OF ENHANCING PHOTOCATALYTIC PROPERTY 9
1.2.3.1 BAND GAP ADJUSTMENT (DOPING) 9
1.2.3.2 MORPHOLOGY CONTROL 10
1.2.3.3 NANOCOMPOSITES (HETEROJUNCTIONS) 11
1.2.3.4 SURFACE PLASMA RESONANCE (SPR) 14
1.2.3.5 COMPLEX METAL OXIDES 16
1.3 CUFEO2 (CUPROUS FERRITE) 17
1.3.1 STRUCTURE 17
1.3.2 CHARACTERISTICS 19
1.3.3 SYNTHESIS METHODS 21
1.3.3.1 SPUTTERING METHOD 21
1.3.3.2 SOLID STATE REACTION 24
1.3.3.3 SOL-GEL METHOD 27
1.3.3.4 HYDROTHERMAL METHOD 28
1.4 MOTIVATION AND OBJECTIVE 31
CHAPTER 2 EXPERIMENTAL 32
2.1 MATERIALS 32
2.2 EXPERIMENTAL PROCEDURE 32
2.2.1 SUBSTRATE CLEANING 32
2.2.2 PREPARATION OF SEED LAYER 33
2.2.3 HYDROTHERMAL SYNTHESIS 36
2.3 CHARACTERIZATIONS 38
2.3.1 X-RAY DIFFRACTION (XRD) 38
2.3.2 SCANNING ELECTRON MICROSCOPY (SEM) 39
2.3.3 X-RAY PHOTOELECTRON SPECTROSCOPY (XPS) 41
2.3.4 PHOTODEGRADATION 42
2.3.5 PEC REACTION MEASUREMENT 43
2.3.6 UV-VIS MEASUREMENT 43
CHAPTER 3 RESULTS AND DISCUSSION 45
3.1 FABRICATION AND CHARACTERIZATION OF CUFEO2 THIN FILM 46
3.1.1 EFFECT OF SEED LAYERS 47
3.1.2 VARIOUS THICKNESSES OF SEED LAYERS 48
3.1.3 DEPOSITION METHOD OF SEED LAYERS 49
3.1.4 HIGHLY TEXTURED CUFEO2 POWDERS AS SEED LAYERS 51
3.1.5 SEM ANALYSIS 52
3.1.6 XPS ANALYSIS 55
3.1.7 UPS ANALYSIS 57
3.1.8 UV-VIS SPECTRA 58
3.1.9 BAND STRUCTURE OF CUFEO2 THIN FILMS 60
3.2 APPLICATION OF CUFEO2 THIN FILMS 61
3.2.1 PHOTODEGRADATION 61
3.2.2 PEC WATER SPLITTING 65
CHAPTER 4 CONCLUSIONS 68
4.1 FABRICATION OF CUFEO2 THIN FLIMS 68
4.2 SEM ANALYSIS 68
4.3 BAND STRUCTURE 68
4.4 PHOTODEGRADATION MEASUREMENT 69
4.5 PEC ANALYSIS 69
REFERENCES 70

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