Synthesis of TiO2 supported on activated carbon by MOCVD:operation parameters study

A novel metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalytic titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate, source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2 mg/(g.h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation energy Ea of 51.09 kJ/mol. TiO2 existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of 773 K and a higher source temperature of 448 K resulted in finely dispersed TiO2 particles, which were mainly in the range of 10-20 nm.     

Synthesis of TiO<Subscript>2</Subscript> supported on activated carbon by MOCVD: operation parameters study

A novel metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalytic titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate, source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2 mg/(g·h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation energy E _a of 51.09 kJ/mol. TiO₂ existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of 773 K and a higher source temperature of 448 K resulted in finely dispersed TiO₂ particles, which were mainly in the range of 10–20 nm. Project (No. 90206007) supported by the National Natural Science Foundation of China     

常压MOCVD法制备TiO_2薄膜及性质研究

利用常压MOCVD法在Si及Al2O3衬底上制备了TiO2薄膜.研究了沉积温度和退火温度对TiO2薄膜结构和形貌的影响,以及TiO2薄膜的光学性质.研究发现,沉积温度为600℃时,制备的TiO2薄膜结构为锐钛矿相,薄膜质量较高.TiO2薄膜在1 090℃高温退火后,薄膜结构完全转变为金红相.TiO2薄膜在可见区域有着高达90%以上透射率,在紫外区域有着强烈的吸收.     

MOCVD法生长ZnO纳米管及光学性能评价

利用金属有机化合物气相沉积(MOCVD)方法在Al2O3(1 1 2 0)衬底上生长高质量的ZnO薄膜,在衬底温度450℃及生长舱压力40 Pa的条件下,我们得到了ZnO纳米管.利用X射线衍射(XRD)对样品的结构进行了分析,利用光致发光(PL)对样品的光学性能进行了评价.     

MOCVD材料生长的在位反射谱监测与表面不均衡平整度的模拟计算

介绍了MOCVD在位反射谱监测的原理,利用高斯分布模拟GaN材料生长过程中表面不均衡平整度,计算其对反射谱的影响。     

气氛及压强对MOCVD红外测温的影响

利用自主搭建的可径向移动的940 nm单波长红外辐射测温仪,研究了Thomas Swan CCS MOCVD第二次Bake过程中,反应室在不同气氛(氢气、氮气以及氢氮混合气体)和不同压强(13.33-53.33 k Pa)下径向温度分布。试验结果表明:压强为13.33 k Pa,MOCVD反应室内的气氛不同时,红外测温结果主要受气体导热系数的影响;在20 L氢气下,反应室内压强越大温度越高;在压强为13.33 k Pa,H2流量的不同对测温影响不大。该研究结果可为MOCVD反应室的红外辐射测温与精确控温提供参考。     

Synthesis of TiO_2 supported on activated carbon by MOCVD:operation parameters study

A novel metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalytic titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate, source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2 mg/(g·h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation energy Ea of 51.09 kJ/mol. TiO2 existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of 773 K and a higher source temperature of 448 K resulted in finely dispersed TiO2 particles, which were mainly in the