具有共轭结构的CDPVA/ZnO复合光催化剂的制备及其可见光催化性能

CDPVA是一种具有共轭多烯序列的聚乙烯醇(PVA)衍生物。通过低温热处理法制备了CDPVA/ZnO复合光催化剂。表征结果显示,PVA经低温热处理后形成了具有一定共轭结构的CDPVA并包覆于纳米ZnO颗粒表面,提高了光催化剂的可见光响应能力,有效促进了光生空穴和电子的分离。当PVA与纳米ZnO的质量比为1∶100时,CDPVA/ZnO的可见光催化活性最高;在催化剂投加量为0.5g/L、初始罗丹明B质量浓度为4mg/L、可见光照射50min的条件下,罗丹明B降解率为97.51%,明显优于纯纳米ZnO;CDPVA/ZnO循环使用9次后仍保持较高的罗丹明B降解率,表明CDPVA的包覆有效抑制了纳米ZnO的光腐蚀,提高了光催化剂的稳定性。

Preparation and visible-light photocatalytic activity of CDPVA/ZnO composite photocatalyst with conjugation structure

CDPVA is a polyvinyl alcohol （PVA）derivative having a conjugated polyene sequence. CDPVA/nano ZnO composite photocatalyst was prepared by low temperature thermal treatment. The characterization results showed that the CDPVA was formed by heat-treating PVA at low temperature and was coated on the surface of ZnO nanoparticles,which can enhance the visible-light responsive ability of the photocatalyst and promote the separation of photo-generated holes with electron. When the mass ratio of PVA to nano ZnO was 1:100,the CDPVA/ZnO exhibited the highest visible-light photocatalytic activity;Under the conditions of photocatalyst addition amount 0.5 g/L,initial Rhodamin B mass concentration 4 mg/L and visible-light irradiation time 50 min,the Rhodamin B degradation rate was up to 97.51%,which was much higher than that on pure nano ZnO;Moreover,after being reused for 9 times,the CDPVA/ZnO still had excellent photocatalytic activity,which indicated that the CDPVA coating on the surface of ZnO nanoparticles effectively inhibited the photocorrosion to the ZnO and improved the stability of the photocatalyst.