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光催化还原废水中的六价铬离子作为一种具有吸引力的处理方法得到广泛的研究.本文报道了一种利用高透明聚乙烯醇/二氧化钛(PVA/TiO_2)纳米复合薄膜光催化还原Cr(Ⅵ)的方法.通过简单的水热法和溶液涂抹技术制备了PVA/TiO_2纳米复合薄膜,并对其进行了表征.结果表明,原位生成的10 nm左右的锐钛矿型TiO_2纳米粒子均匀分散在PVA基体中,该薄膜在可见光下对Cr(Ⅵ)显示出优异的光催化还原速率.机理研究表明,PVA不仅作为TiO_2纳米粒子的透明载体,而且能有效地促进光致电子和空穴的分离.此外,在多次光催化循环中,PVA/TiO_2纳米复合薄膜展示出良好的稳定性和优异的可循环利用性能,并且该薄膜对还原后的Cr(Ⅲ)表现出良好的选择性吸附,从而可以实现废水中铬离子的彻底去除.
Photocatalytic reduction of hexavalent chromium ions in wastewater by photocatalysis has been widely studied as an attractive treatment method.In this paper, a method for photocatalytic reduction of Cr (Ⅵ) with high transparent polyvinyl alcohol / titanium dioxide (PVA / TiO_2) nanocomposite films was reported Ⅵ) was prepared by the simple hydrothermal method and solution coating technique.The results showed that the anatase TiO 2 nanoparticles prepared in-situ at about 10 nm were uniform Dispersed in PVA matrix, the film shows excellent photocatalytic reduction rate for Cr (VI) in visible light.Mechanism studies show that PVA not only acts as a transparent carrier of TiO 2 nanoparticles, but also can effectively promote photoelectrons and holes In addition, the PVA / TiO 2 nanocomposite film shows good stability and excellent recyclability in multiple photocatalytic cycles, and the film shows good selectivity for the reduced Cr (Ⅲ) Adsorption, which can achieve the complete removal of chromium ions in wastewater.