HCS@TiO2光催化复合材料的制备及其染料降解性能

Preparation and degradation dyestuffs performance of HCS@TiO2 photocatalytic composites

  • 摘要: 为了获得性能更加优异的光催化材料,本文通过简单的湿化学法制备了空心碳球(HCS)@TiO2光催化复合材料,并对其进行了表征。形貌与结构的表征结果显示,TiO2纳米颗粒均匀地锚定在HCS表面,形成亲水性强、比表面积大、热稳定性优异的球形复合材料,HCS@TiO2复合材料中TiO2的质量分数为80wt%;光电化学性质分析表明HCS@TiO2复合材料禁带宽度更小,光响应范围更大,光生电子还原能力更强。在模拟太阳光下,以活性红195 (RR195)为实验对象,测试制备的HCS@TiO2复合材料的光催化降解染料的性能和循环稳定性。结果表明:HCS@TiO2光生电子空穴对的分离效率更高,光催化活性优异,在120 min内染料降解率为95.36%,5次循环后仍高达93.34%,稳定性高,且易于回收。同时结合自由基捕获实验及电子顺磁共振光谱,对HCS@TiO2光催化复合材料的光催化机制进行了探究,证实了\text•\rmO_2^ - 在光催化反应体系中起主要作用。

     

    Abstract: In order to obtain more efficient photocatalytic materials, hollow carbon sphere (HCS)@TiO2 photocatalytic composites was prepared by a facile wet-chemical method and characterized. The results of structural and morphology characterization showed that TiO2 nanoparticles were anchored uniformly on the surface of HCS, forming a spherical composites with high hydrophilia and specific surface area and excellent thermostability, the mass percentage of TiO2 anchored on HCS@TiO2 composites was 80wt%. The analysis of photoelectric chemical properties showed that HCS@TiO2 composites had smaller bandgap width, wider light response range, and stronger photogenic electron reduction ability. Using Reactive Red 195 (RR195) as the experimental object, the photocatalytic degradation dyes performance and cyclic stability of HCS@TiO2 composites were tested under simulated sunlight. The results show that the separation efficiency of photogenic electron hole pairs in the HCS@TiO2 is higher, and the photocatalytic activity is excellent. The degradation rate is 95.36% within 120 min, and it still reaches 93.34% after 5 cycles, with high stability and easy recovery. At the same time, the photocatalytic mechanism of HCS@TiO2 photocatalytic composites was proposed by combining free radical capture experiment and electron paramagnetic resonance spectroscopy. It was confirmed that \text•\rmO_2^ - plays a major role in the photocatalytic reaction system.

     

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