炭表面改性对负载型TiO_2/活性炭复合光催化剂性能的影响

采用HNO3、H2O2和O3对商品活性炭进行表面改性处理,考察了改性处理对活性炭表面基团、负载TiO2以及所形成的TiO2/活性炭复合光催化剂性能的影响。利用傅里叶红外光谱(IR)、X射线光电子能谱(XPS)、扫描电镜(SEM)及氮气吸附等手段对材料进行了表征。结果表明,3种改性方法均可有效提高活性炭载体表面的含氧官能团数量,但是对活性炭的比表面积和孔容影响不大;H2O2和O3对活性炭载体改性后可以提高对钛前驱体的吸附性能,HNO3改性有利于TiO2颗粒在活性炭表面的分散。使用改性后的活性炭作为载体制备的TiO2/活性炭光催化降解甲基橙的性能均高于未改性的TiO2/活性炭催化剂,其中以HNO3改性后的TiO2/活性炭活性最高。

Effect of Active Carbon Modification on Photocatalytic Performance of TiO2/AC Catalysts

Commercial activated carbon(AC) was modified by surface treatment with three reagents HNO3,H2O2 and O3.The influence of treatment on the function groups of carbon surface,deposition of TiO2 and photocatalytic performance of resultant TiO2/AC composite catalysts was investigated.Fourier transform infrared spectrometer(FR-IR),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM) and the nitrogen adsorption were used to characterize AC and TiO2/AC.The results showed that the contents of oxygen containing groups on the activated carbon surface increased.However,there was a little change in the surface area and average pore size of AC.The modification with H2O2 and O3 increased the absorption adsorbability of AC for TiO2 precursor.The modification with HNO3 favored high dispersibility of TiO2 deposited on the carbon surface.It was found that TiO2/ACs form modified carbons had higher photocatalytic performance for the MO degradation than that of original carbon.The TiO2/AC via HNO3-modified carbon was the best.