A novel photocatalyst with [email protected] structure was prepared by alternately assembling titania nanosheets (TNS) and reduced graphene oxide (r-GO) on coal fly ash (CFA) microspheres via the layer-by-layer (LBL) assembly approach. The as-prepared samples [email protected](r-GO/TNS)_n were characterized by SEM, HRTEM, XRD, FTIR, Raman, XPS, UV–vis, PL and their photocatalytic activities were evaluated by the photodegradation of methylene blue (MB) under UV irradiation. The results showed that TNS and r-GO wrapped on the surface of CFA alternately and tightly, which was very helpful not only to avoid the detachment of TNS and r-GO from the surface of CFA in the progress of using, but also to reduce the recombination of photogenerated electrons and holes due to excellent mobility of charge carriers on the surface of r-GO. The layer number of wrapped r-GO/TNS was found to be an important factor in the photocatalytic activity of composite. In our experimental conditions, [email protected](r-GO/TNS)₈ presented the best photocatalytic activity, and the degradation efficiency of MB was improved to 55% from 32% of [email protected](r-GO/TNS)₂. The improvement could be attributed to several advantageous factors by introduction of r-GO, such as the fast charge-carrier transfer, the reduction of the charge recombination rate, the improved light harvesting and the larger specific surface area.

通过逐层（LBL）组装方法在煤粉煤灰（CFA）微球上交替组装二氧化钛纳米片（TNS）和还原氧化石墨烯（r-GO），制备了一种具有[电子邮件保护]结构的新型光催化剂。准备好的样品[受电子邮件保护]（r-GO / TNS）_n用SEM，HRTEM，XRD，FTIR，拉曼，XPS，UV-vis，PL对其进行表征，并通过亚甲基蓝（MB）在紫外线辐射下的光降解来评估其光催化活性。结果表明，TNS和r-GO交替紧密地包裹在CFA的表面，这不仅有助于避免TNS和r-GO在使用过程中从CFA的表面脱离，而且有助于减少由于r-GO表面电荷载流子的出色迁移性，光生电子和空穴的复合。发现包裹的r-GO / TNS的层数是复合材料光催化活性的重要因素。在我们的实验条件下，[电子邮件保护]（r-GO / TNS）₈表现出最好的光催化活性，MB的降解效率从[电子邮件保护]（r-GO / TNS）_2的32％提高到55％。引入r-GO可归因于几个有利因素，例如快速的载流子转移，降低的电荷复合速率，改善的光收集和更大的比表面积。