فهرس المقالات ZnO nanorod

• حرية الوصول المقاله
  • صفحة الملخص
  • نص كامل
  
  1 - Application of ZnO Nanorods for the Synthesis of Thiazole Derivatives via Multicomponent Reactions in Water
  Ali Varasteh Moradi
  Simple three-component reactions between dialkyl acetylenedicarboxylate, primary amines and isothiocyanates in the presence of catalytic amount of ZnO nanorods are investigated in water at room temperature which produced thiazole derivatives in good yields.

  Simple three-component reactions between dialkyl acetylenedicarboxylate, primary amines and isothiocyanates in the presence of catalytic amount of ZnO nanorods are investigated in water at room temperature which produced thiazole derivatives in good yields. تفاصيل المقالة
• حرية الوصول المقاله
  • صفحة الملخص
  • نص كامل
  
  2 - Structural, Optical and Ultra-Violet Photodetection Properties of ZnO Nanorods with Various Aspect Ratios
  Saeed Safa Elham Hasani Majid Zareh
  ZnO nanorods with various lengths were synthesized by a two-stage route (by changing the time of growth between 0-240 min) and were characterized using XRD, SEM, UV–Vis and PL techniques. The SEM and XRD results confirmed a fast growth of (0 0 2) plane in the pref أکثر

  ZnO nanorods with various lengths were synthesized by a two-stage route (by changing the time of growth between 0-240 min) and were characterized using XRD, SEM, UV–Vis and PL techniques. The SEM and XRD results confirmed a fast growth of (0 0 2) plane in the preferential longitudinal orientation, in contrast to lateral growth and therefore, by increasing the time of hydrothermal growth, nanorods with higher aspect ratios are obtained. Naturally, by increasing the length of nanorods, not only the average transmittance in both near ultraviolet and visible ranges is decreased, but also the PL peaks are red-shifted and extinct. Finally, ultra-violet photodetection of the samples shows that higher active surface area (with respect to the time of growth) is appropriate for photo-induced interactions leading to higher UV-sensitivity. تفاصيل المقالة
• حرية الوصول المقاله
  • صفحة الملخص
  • نص كامل
  
  3 - Influence of Cr dopant on the microstructure and optical properties of ZnO nanorods
  Saeed Safa A. Masoudi Nejad
  One-dimensional (1D) undoped and Cr doped ZnO nanorods with average length of 1 µm and diameter of 80 nm were synthesized using hydrothermal method where a fast growth of ZnO nanorods on the seed layer was observed. Afterwards, the effects of Cr dopant on structur أکثر

  One-dimensional (1D) undoped and Cr doped ZnO nanorods with average length of 1 µm and diameter of 80 nm were synthesized using hydrothermal method where a fast growth of ZnO nanorods on the seed layer was observed. Afterwards, the effects of Cr dopant on structural, surface morphology and optical properties of nanorods were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and ultra-violet visible (UV-Vis) spectroscopy. The results showed that ZnO has a wurtzite hexagonal structure and that the Cr atoms were well incorporated into the ZnO crystal structure. Moreover, it was found that the Cr atoms could facilitate the preferential growth of nanorods in C-axis. Also, it was concluded from optical properties that doped ZnO nanorods was so appropriate for photocatalytic applications because the optical band gap. For example, the calculated band gap of ZnO nanorod decreased from 3.12 eV for pure ZnO nanorods to about 2.41eV for 3 at. % Cr doped ZnO nanorods which is quite enough to be activated even at visible (550nm) light for photocatalyst aims. تفاصيل المقالة
• حرية الوصول المقاله
  • صفحة الملخص
  • نص كامل
  
  4 - Investigating structural, optical and photocatalytic properties of hydrothermally synthesized ZnO nanorod arrays with various aspect ratios
  Saeed Safa Ali Khayatian eliza rokhsat Mehrdad Najafi
  ZnO nanorods with various aspect ratios (by changing the time of growth between 0-240 min) were synthesized using hydrothermal method and were investigated using XRD, SEM, UV–Vis and PL. It was found that growth time is directly coupled with the length, orientatio أکثر

  ZnO nanorods with various aspect ratios (by changing the time of growth between 0-240 min) were synthesized using hydrothermal method and were investigated using XRD, SEM, UV–Vis and PL. It was found that growth time is directly coupled with the length, orientation and aspect ratio of the nanorod arrays. The optical transmittance of the NR arrays indicated a regular decrement of average transmittance with increasing the aspect ratio of NRs in the visible range. The optical constants (absorption coefficient, extinction coefficient and refractive index) can be account as a function of refractive index were determined. The porous ZnO nanorod with the thickness of ∼ 1560 nm and texture coefficient of 0.96 for (002) plane exhibits the average visible transmittance <60%, refractive index 1.34, packing density 0.26 and lowest optical band gap, was fabricated in the longest time of hydrothermal growth (240 min). As the growth time was increased, the photoluminescence properties was sustained a general weakening tendency and a red-shift of UV-emission peak position. The UV-assisted photocatalytic degradation of 4-Nitrophenol (4-NP) of ZnO NRs were investigated. The considerable photocatalytic performance of ZnO NRs with highest aspect ratio was explained by its porosity and optical characteristics. تفاصيل المقالة
• حرية الوصول المقاله
  • صفحة الملخص
  • نص كامل
  
  5 - پوشش نانو سیم‌های اکسید روی بر روی الکترود آرایه های درهمتنیده طلا و بررسی عملکرد نانو حسگر گازهای الکلی
  حمید غیور امین نکوبین امیرعباس نوربخش
  الکترود آرایه‌های درهمتنیده با استفاده از نانولیتوگرافی طلا بر روی بستر آلومینایی با روش PVD ساخته شد.از نانو میله ‌اکسید روی به عنوان ماده حسگر استفاده شده که به روش هیدروترمال بر روی بذر لایه ای از اکسید روی سنتز شد. نانومیله‌های سنتز شده با استفاده از تفرق پرتو ایکس‌ أکثر

  الکترود آرایه‌های درهمتنیده با استفاده از نانولیتوگرافی طلا بر روی بستر آلومینایی با روش PVD ساخته شد.از نانو میله ‌اکسید روی به عنوان ماده حسگر استفاده شده که به روش هیدروترمال بر روی بذر لایه ای از اکسید روی سنتز شد. نانومیله‌های سنتز شده با استفاده از تفرق پرتو ایکس‌(XRD)، میکروسکوپ الکترونی عبوری با تفکیک بالا(HR-TEM) ، میکروسکوپ الکترونی روبشی (SEM) و میکروسکوپ نیروی اتمی (AFM)مشخصه یابی گردید. عملکرد حسگری برای چهار گاز الکلی بررسی شد.به منظور بهینه کردن شرایط حسگری حساسیت و پاسخ نانومیله های اکسید روی در گستره دمایی 50 تا 300 درجه سانتیگراد بررسی شد. دمای کاری 47 درجه ساتیگراد به عنوان دمای بهینه انتخاب گردید و متغیرهای مهمی همچون حساسیت حسگر،زمان پاسخ دهی و زمان بازیابی برای چهار گاز در دمای ثابت و برای غلظتهای مختلف به دست آمد. نتایج حاصل نشان داد که با استفاده از نانومیله های همراستای اکسید روی؛ گازهای الکلی در دمای پایین با حساسیت بالا قابل تشخیص هستند. تفاصيل المقالة