In this work, we’ve made SnO<sub>2</sub> flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniq...In this work, we’ve made SnO<sub>2</sub> flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniques to characterize SnO<sub>2</sub> flower-shaped by (SEM, TEM, XRD, BET and XPS) instruments. Confirmatory tests carried out have proven that the surface of the tetragonal structure of SnO<sub>2</sub> has a rough surface which makes it excellent for its gas-sensing properties. The gas detection test of SnO<sub>2</sub> flower-shaped proved that it possesses the selectivity of formaldehyde gas (about 30), the optimum operating temperature of the sensor is 220<span style="white-space:nowrap;"><span style="white-space:nowrap;">°</span></span>C, and also the sensor has a high response time and recovery time is (5 s and 22 s) to 100 ppm, respectively. Particularly, the sensor has an obvious response value (2) when exposed to 5 ppm formaldehyde. As well, the mechanism of gas-sensing was also discussed.展开更多
Carbon nanotubes flower (CNTs-F) films were prepared by catalytic chemical vapor deposition (CVD) on a platinum (Pt) thin layer, supported on a silicon wafer. The products were synthesized from an aerosol composed of ...Carbon nanotubes flower (CNTs-F) films were prepared by catalytic chemical vapor deposition (CVD) on a platinum (Pt) thin layer, supported on a silicon wafer. The products were synthesized from an aerosol composed of ferrocene and toluene, as catalyst and carbon precursor respectively, at 820. The high synthesis temperature induces a modification of a Pt thin layer to a nano-structured island giving rise to the formation of CNTs-F during the following films growth step by CVD process. The suggested mechanism involves the selective diffusion of the catalyst and carbon atoms through the Pt grain boundaries. This results in the appearance of flower-like structures with 3-and 4-fold symmetries.展开更多
以醋酸锌、柠檬酸钠、氢氧化钠为原料,采用沉淀法制备了片层交叉花状纳米氧化锌。利用扫描电镜(SEM)、X射线衍射(XRD)、Zeta电位对所得样品进行了表征。通过考察温度对样品形貌的影响,对产物的生长机理做了简单研究。并以罗丹明B为模型...以醋酸锌、柠檬酸钠、氢氧化钠为原料,采用沉淀法制备了片层交叉花状纳米氧化锌。利用扫描电镜(SEM)、X射线衍射(XRD)、Zeta电位对所得样品进行了表征。通过考察温度对样品形貌的影响,对产物的生长机理做了简单研究。并以罗丹明B为模型分子,采用紫外-可见光谱(UV-Vis)考察了样品的光催化性能。研究结果表明:在不同温度下得到的产物形貌存在着明显区别。在25℃条件下制备的氧化锌为片层交叉花状。该纳米材料在紫外-可见光下具有较高的光催化活性和稳定性,照射12 h可以使罗丹明B的降解率接近100%。样品的Zeta电位为-13.2 e V,表明样品可能存在结构缺陷,花状氧化锌纳米球粒子有大量的Zn2+空位或过剩的O2-。同时样品具有较大的比表面积,因此在可见光条件下的催化活性与紫外光下的催化活性相近。展开更多
文摘In this work, we’ve made SnO<sub>2</sub> flower formed with the aid of using easy test steps, and without cost, which is the hydrothermal approach and without a template. We have used a variety of techniques to characterize SnO<sub>2</sub> flower-shaped by (SEM, TEM, XRD, BET and XPS) instruments. Confirmatory tests carried out have proven that the surface of the tetragonal structure of SnO<sub>2</sub> has a rough surface which makes it excellent for its gas-sensing properties. The gas detection test of SnO<sub>2</sub> flower-shaped proved that it possesses the selectivity of formaldehyde gas (about 30), the optimum operating temperature of the sensor is 220<span style="white-space:nowrap;"><span style="white-space:nowrap;">°</span></span>C, and also the sensor has a high response time and recovery time is (5 s and 22 s) to 100 ppm, respectively. Particularly, the sensor has an obvious response value (2) when exposed to 5 ppm formaldehyde. As well, the mechanism of gas-sensing was also discussed.
基金the Conseil Regional of PACA,the Conseil Général du Var,and Toulon Provence Mediterranean for their financial support.
文摘Carbon nanotubes flower (CNTs-F) films were prepared by catalytic chemical vapor deposition (CVD) on a platinum (Pt) thin layer, supported on a silicon wafer. The products were synthesized from an aerosol composed of ferrocene and toluene, as catalyst and carbon precursor respectively, at 820. The high synthesis temperature induces a modification of a Pt thin layer to a nano-structured island giving rise to the formation of CNTs-F during the following films growth step by CVD process. The suggested mechanism involves the selective diffusion of the catalyst and carbon atoms through the Pt grain boundaries. This results in the appearance of flower-like structures with 3-and 4-fold symmetries.
文摘以醋酸锌、柠檬酸钠、氢氧化钠为原料,采用沉淀法制备了片层交叉花状纳米氧化锌。利用扫描电镜(SEM)、X射线衍射(XRD)、Zeta电位对所得样品进行了表征。通过考察温度对样品形貌的影响,对产物的生长机理做了简单研究。并以罗丹明B为模型分子,采用紫外-可见光谱(UV-Vis)考察了样品的光催化性能。研究结果表明:在不同温度下得到的产物形貌存在着明显区别。在25℃条件下制备的氧化锌为片层交叉花状。该纳米材料在紫外-可见光下具有较高的光催化活性和稳定性,照射12 h可以使罗丹明B的降解率接近100%。样品的Zeta电位为-13.2 e V,表明样品可能存在结构缺陷,花状氧化锌纳米球粒子有大量的Zn2+空位或过剩的O2-。同时样品具有较大的比表面积,因此在可见光条件下的催化活性与紫外光下的催化活性相近。
