Shape control of ZnO nanoparticles and growth of ZnO nanorods by hydrothermal method

Zinc oxide (ZnO), a wide bandgap (3.4 eV) Ⅱ-Ⅵ compound semiconductor, has a stable wurtzite structure with lattice spacing a= 0.325 nm and c= 0.521 nm. Zinc oxide powders were synthesized by a simple hydrothermal process in the different reaction pH, temperatures, and precursor concentrations. Nanoparticles were formed by simple hydrothermal synthesis of mixing aqueous solutions of zinc nitrate hexahydrate (Zn(NO3)2· 6H2O) and NaOH under controlled process conditions such as precursor reaction pH, concentration and temperatures. And zinc oxide seed layer was coated by Metal-Organic Decomposition (MOD) process, and then the zinc oxide nanorods on ZnO seed layer were grown by hydrothermal process from 0.3 M at pH 7, 80 ℃, 1 h. Single phase zinc oxide particles can be easily synthesized in lower precursor concentration, higher reaction pH and temperature. Zinc oxide mophology of shorted hexagonal tablet crystals, multipods, interconnected or separate rods, could be obtained and the shapes would be efficiently controllable by changing hydrothermal conditions. ZnO nanorods can be easily formed on the ZnO coated glass substrate in low temperature using ZnCl2.1. 서 론 1 2. 이론적 배경 5 2.1. Zinc Oxide (ZnO) 5 2.1.1. ZnO의 일반적인 특성 5 2.1.2. ZnO의 결정구조 및 특성 5 2.2. 분말 합성 기술 8 2.2.1. 습식화학적 합성법(Wet-chemical synthesis routes)에 의한 분말 합성 8 2.2.1.1. 공침법(Co-Precipitation) 8 2.2.1.2. 수열합성법(Hydrothermal Method) 8 2.2.1.3. 졸-겔법(Sol-Gel Synthesis Method) 11 2.2.2. 기상 합성법에 의한 분말 합성 11 2.2.2.1. 화염법 11 2.2.2.2. 기상 응축법(Gas Phase Condensation Method) 12 2.2.2.3. 화학적기상응축법(Chemical Vapor Condensation Method) 12 2.3. MOD법(Metal-organic Decomposition Method) 13 3. 실험방법 15 3.1. ZnO 분말 제조 15 3.2. ZnO nanorod 성장 19 3.3. ZnO 물성 측정 21 4. 실험결과 및 고찰 21 4.1. 수열합성법으로 제조한 ZnO 분말 특성 21 4.1.1. pH 별 온도에 따른 ZnO 분말의 특성 21 4.1.2. 몰 농도에 따른 ZnO 분말의 특성 32 4.2. H2O2 첨가 후 수열합성법으로 제조한 ZnO 분말 특성 39 4.2.1. pH 별 온도에 따른 ZnO 분말의 특성 39 4.2.2. 몰 농도에 따른 ZnO 분말의 특성 50 4.3. ZnO 나노로드 성장 56 5. 결 론 61 6. 참고문헌 6

Antifibrotic effects of A0023 ethyl acetate fraction against TAA (thioacetamide)-Induced cell culture and mouse model systems

Thesis(master`s)--서울대학교 대학원 :제약학과,2006.Maste