The present article reports a novel self-standing nanostructured Au-Cu(I)@Na2Ti6O13 plasmonic photocatalytic membrane, which is prepared by a hydrothermal reaction followed by a simple sub-sequent heat treatment process. The morphological structure, elemental composition, crystalline phases, and optical properties of the membrane were studied in detail by field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and ultraviolet-visible spectroscopy. Compared with that of a pure Na2Ti6O13 membrane, the Au-Cu(I)@Na2Ti6O13 membrane displayed much higher photocatalytic activity for the decompo-sition of acetaldehyde, a typical volatile organic compound, under visible light illumination. It was found that the photocatalytic activity of the Au-Cu(I)@Na2Ti6O13 membrane increased as the amount of Au was increased. The membrane loaded with 2.85 wt% Au showed the highest photo-catalytic activity in the decomposition of acetaldehyde of the investigated materials. We found that in the photocatalyst membrane, Na2Ti6O13 acted as a support material, Au displayed plasmonic absorption, and Cu(I) behaved as a co-catalyst. The present membrane materials can avoid the self-aggregation typically observed during the course of photocatalytic reactions. As a result, they can be easily separated, recycled, and reactivated after their practical application, making these functional materials attractive for use in air cleaning applications.%室内环境的空气质量对人们生活和健康的影响很大.其中挥发性有机物(VOCs)如乙醛、甲醛、丙酮、苯和甲苯等是室内环境污染的主要来源之一,它们会引起机体免疫力水平失调,影响中枢神经功能,还可影响消化系统,严重时可损伤肝脏和造血功能等.因此,消除这些VOCs变得刻不容缓.本文报道了一种新型等离子体纳米Au-Cu(I)@Na2Ti6O13光催化薄膜.钛酸盐材料容易制备,且具有良好的化学和机械性能,目前多应用于电容器、传感器和光催化领域.此薄膜采用水热法制备并进一步热处理得到,该法简单易操作,水热时间较短且成本低廉.另外通过热置沉积的方法分别将Au纳米颗粒和Cu(I)成功负载到Na2Ti6O13滤膜上.分别使用场发射扫描电子显微镜(FE-SEM)、透射电子显微镜(TEM)、X射线光电子光谱仪(XPS)、X射线衍射仪(XRD)和UV-Vis光谱仪研究了薄膜的形态结构、元素组成、晶相组成和光学性能.SEM和TEM结果表明,Na2Ti6O13滤膜由超长的Na2Ti6O13纳米纤维组成.纳米纤维之间存在较大的孔,可以使空气自由通过.XRD,XPS和UV-Vis结果发现,Au纳米颗粒和铜纳米簇成功地负载在Na2Ti6O13滤膜上,且铜呈无定形态,价态为+1.相应的催化结果表明,在可见光照射下,相比于纯Na2Ti6O13滤膜,Au-Cu(I)@Na2Ti6O13滤膜显示出非常高的降解乙醛活性.结果发现,Na2Ti6O13滤膜的可见光活性随着负载的Au纳米颗粒含量的增加呈现先增加后降低的趋势,当Au纳米颗粒的含量为2.85 wt%时达到最大.使用超长Na2Ti6O13纳米纤维作为支撑材料,Au纳米颗粒的等离子体可见光吸附导致电子从Au纳米颗粒迁移到Na2Ti6O13的导带,并被表面负载的Cu(I)俘获,有效地避免了Na2Ti6O13中导带电子和留在Au纳米颗粒上空穴的复合,延长了电子和空穴的寿命,进而提高了滤膜的可见光催化活性.Na2Ti6O13滤膜可以有效地避免粉体在光催化反应过程中发生团聚,因而在实际应用过程中易分离,避免了二次污染,且可以循环使用,因此成本低,有望用作空气净化的功能材料.
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