A.A.A. Saleh
,
X.J. Zhai
,
Y.C. Zhai
,
Y. Fu
,
M.M. Elomella
金属学报(英文版)
Photocatalytic degradations of p-nitrochlorbenzene (p-NCB) with distilled water were
investigated with ZnO crystals (catalyst) of 70nm in diameter under UV irradiation.
The suitable experimental conditions are determined as: ZnO 0.25g, pH 7, p-NCB
concentration 30mg/L. These variables in terms of the degradation rate have been
discussed, which was defined as the rate of the initial degradation to the final degradation of p-NCB. When all of the experimental degradation rate values are plotted as a
function of irradiation time, all of the points appeared on a single line for wide range of
p-NCB degradations. On the basis of these results, it has been concluded that at lower
ZnO catalyst amount, much of the light is transmitted through the slurry in the container beaker, while at higher catalyst amount, all the incident photons are observed
by the slurry. Degradation rates of p-NCB were found to decrease with increasing
solution pH. It has been concluded that the maximum degradation rate values of p-NCB under principally the same experimental conditions mentioned above are 97.4%,
98.8% and 95.5% at 100min respectively. The results suggest that the photocatalytic
degradation is initiated by an oxidation of the p-NCB through ZnO surface-adsorbed
hydroxyl radicals. Absorption spectra are recorded using spectrophotometer before and
after UV-irradiation in the wavelength range 200--400nm at room temperature. It
is found that the variation of irradiation time over the range 20--100min resulted in
change in the form of the spectrum linear absorption and a higher maximum value
will be obtained at longer irradiation time.
关键词:
reactive evaporation method
,
null
,
null
,
null
徐腊梅
,
江龙
,
淡宜
高分子材料科学与工程
以锐钛型二氧化钛作为催化剂在紫外光下催化降解聚乙烯醇（PVA）溶液。通过化学需氧量除去率和相对黏度测定,探讨了不同初始浓度PVA溶液紫外光催化降解的规律：随紫外光辐照时间延长,PVA溶液化学需氧量除去率增加;PVA溶液相对黏度呈先下降后上升再下降趋势;较低初始质量浓度（0.4 g/L）PVA溶液比较高初始质量浓度（1 g/L）PVA溶液更容易降解。通过紫外-可见吸收光谱和红外吸收光谱分析,研究了PVA经紫外光降解后的结构变化,结果表明,降解伊始,PVA分子链被破坏,有碳碳双键和羰基形成,而进一步降解后碳碳双键消失。
关键词:
聚乙烯醇
,
二氧化钛
,
紫外光
,
光催化降解
李翠霞
,
金海泽
,
杨志忠
,
杨轩
,
董其铮
,
厉婷婷
无机材料学报
doi:10.15541/jim20160349
采用溶胶-凝胶法,以氧化石墨烯(GO)、钛酸四丁酯(TBT)为原料,聚乙烯吡咯烷酮(PVP)为结构引导剂,柠檬酸为水解抑制剂和表面活性剂原位合成不同GO含量的介孔氧化石墨烯/二氧化钛复合材料(GO/TiO2),再经过紫外灯辐照还原获得介孔还原氧化石墨烯/二氧化钛复合材料(RGO/TiO2).通过X射线衍射(XRD)、透射电镜(TEM)、比表面积(BET)、紫外-可见漫反射(UV-Vis DRS)和荧光光谱(PL)对样品进行分析表征,研究了RGO/TiO2的形貌、孔径分布情况,RGO的引入对光生电子-空穴对寿命、吸附性能、光催化性能的影响.分别在紫外光和太阳光条件下评价了复合材料的光催化性能,并在紫外光条件下,对催化剂进行了多次回收循环测试.测试结果表明:TiO2均匀地生长于RGO表面,RGO/TiO2为介孔材料;RGO的引入可以有效地抑制光催化剂中光生-电子空穴对的复合,提高吸附性能和光催化性能,7wt％RGO/TiO2显示出对甲基橙的最佳吸附效果;5wt％RGO/TiO2对甲基橙具有最佳光催化效果和稳定的催化活性,经过4次循环后,紫外光照50 min,对甲基橙的降解率仍能达到首次降解效率的90％以上.
关键词:
还原氧化石墨烯
,
二氧化钛
,
介孔
,
紫外光
,
太阳光
