论文部分内容阅读
已知金红石光催化降解水中有机物的活性远低于锐钛矿和板钛矿。本文报道,加入少量钨酸铜能显著加快金红石光催化降解水中苯酚。反应速率增加的幅度不仅远高于在相同煅烧温度(600°C)下制得的锐钛矿和板钛矿,而且随金红石煅烧温度(150-800°C)的增加持续增加。这些现象说明通过加入助催化剂钨酸铜,高温焙烧温度合成的金红石所具有的高的固有光催化活性可以被开发出来。此外,在过量苯酚存在下,H_2O_2的生成量随钨酸铜的加入量而先增加后减少,并且该趋势与苯酚降解速率基本一致。钨酸铜的这种正效应归结于固态的钨酸铜,而不是溶于水中的铜离子。(光)电化学测试表明,体系发生了从受光激发的金红石到钨酸铜的电子转移。这将提高光生载流子的分离效率,从而增大了O_2还原和苯酚降解的速率。
It is known that photocatalytic degradation of organics in water by rutile is far less active than anatase and brookite. This article reports that the addition of a small amount of copper tungstate can significantly accelerate the phenol photocatalytic degradation of water in rutile. The rate of increase of reaction rate is not only much higher than that of anatase and brookite prepared at the same calcination temperature (600 ° C), but also increases with the calcination temperature of rutile (150-800 ° C). These phenomena indicate that the high intrinsic photocatalytic activity of rutile synthesized by the calcination at a high temperature can be developed by adding the co-catalyst copper tungstate. In addition, in the presence of excess phenol, the amount of H 2 O 2 first increases and then decreases with the addition of copper tungstate, and the trend is basically consistent with the phenol degradation rate. This positive effect of copper tungstate is attributed to solid copper tungstate rather than copper ions dissolved in water. (Photo) Electrochemical tests show that the system undergoes electron transfer from photoreactive rutile to copper tungstate. This will increase the photo-generated carrier separation efficiency, thereby increasing O 2 reduction and phenol degradation rate.