物理化学学报 >> 2016, Vol. 32 >> Issue (7): 1758-1764.doi: 10.3866/PKU.WHXB2016032805

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CuWO4促进金红石TiO2光催化降解苯酚及其可能机理

罗邦德,熊贤强,许宜铭*()   

  • 收稿日期:2016-02-01 发布日期:2016-07-08
  • 通讯作者: 许宜铭 E-mail:xuym@zju.edu.cn
  • 基金资助:
    国家自然科学基金(21377110)

Improved Photocatalytic Activity for Phenol Degradation of Rutile TiO2 on the Addition of CuWO4 and Possible Mechanism

Bang-De LUO,Xian-Qiang XIONG,Yi-Ming XU*()   

  • Received:2016-02-01 Published:2016-07-08
  • Contact: Yi-Ming XU E-mail:xuym@zju.edu.cn
  • Supported by:
    National Natural Science Foundation of China(21377110)

摘要:

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 ℃)下制得的锐钛矿和板钛矿,而且随金红石煅烧温度(150-800 ℃)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,H2O2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O2还原和苯酚降解的速率。

关键词: 金红石, 钨酸铜, 过氧化氢, 有机物降解, 光催化, 电荷转移

Abstract:

Rutile is much less active than anatase and brookite for the photocatalytic degradation of organic pollutants in aqueous solution. In this work, we found that addition of a trace amount of CuWO4 greatly accelerated phenol degradation in an aerated aqueous suspension of rutile. The increased rate was not only much higher than those of anatase and brookite, prepared at the same temperature (600 ℃), but also increased continuously with the sintering temperature of rutile from 150 to 800 ℃. These observations indicate that the high intrinsic photocatalytic activity of rutile produced at a high sintering temperature can be exploited by using co-catalyst CuWO4. Furthermore, as the amount of CuWO4 added to the suspension increased, the amount of H2O2 produced in the presence of excess phenol increased and then decreased; the trend was similar to that observed for phenol degradation. The observed positive effect of CuWO4 is mainly caused by solid CuWO4 rather than Cu2+ ions in aqueous solution. A (photo)electrochemical measurement showed that interfacial electron transfer occurred from the irradiated rutile to CuWO4. This would improve the charge-separation efficiency, and consequently increase the rates of O2 reduction and phenol degradation.

Key words: Rutile, CuWO4, H2O2, Organic degradation, Photocatalysis, Charge transfer

MSC2000: 

  • O649