Liu Yanbiao, Liu Xiang, Yang Shengnan, Li Fang, Shen Chensi, Ma Chunyan, Huang Manhong, Sand Wolfgang
Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Nanomaterials (Basel). 2018 Sep 5;8(9):688. doi: 10.3390/nano8090688.
In this study, the authors rationally designed a high-performance catalytic filter for continuous flow catalysis. The catalytic filter consisted of ligand-free nanoscale gold (nano-Au) catalysts and nitrogen-doped graphene (N-rGO). The Au catalyst was fabricated in situ onto a pre-formed N-rGO support by the NaBH₄ reduction of the Au precursor, and the size of the nano-Au was fine-tuned. A hydrothermal pretreatment of graphene oxide enriched nitrogen-containing species on the surface of two-dimensional graphene supports and enhanced the affinity of Au precursors onto the support via electrocatalytic attraction. The nano-Au catalysts acted as high-performance catalysts, and the N-rGO acted as ideal filter materials to anchor the catalysts. The catalytic activity of the as-designed catalytic filter was evaluated using 4-nitrophenol (4-NP) hydrogenation as a model catalytic reaction. The catalytic filters demonstrated superior catalytic activity and excellent stability, where a complete 4-nitrophenol conversion was readily achieved via a single pass through the catalytic filter. The as-fabricated catalytic filter outperformed the conventional batch reactors due to evidently improved mass transport. Some key operational parameters impacting the catalytic performance were identified and optimized. A similar catalytic performance was also observed for three 4-nitrophenol spiked real water samples (e.g., surface water, tap water, and industrial dyeing wastewater). The excellent catalytic activity of the nano-Au catalysts combined with the two-dimensional and mechanically stable graphene allowed for the rational design of various continuous flow catalytic membranes for potential industrial applications.
在本研究中，作者合理设计了一种用于连续流动催化的高性能催化过滤器。该催化过滤器由无配体纳米级金（nano-Au）催化剂和氮掺杂石墨烯（N-rGO）组成。通过NaBH₄还原金前驱体将Au催化剂原位制备在预先形成的N-rGO载体上，并对纳米Au的尺寸进行了微调。氧化石墨烯的水热预处理使二维石墨烯载体表面富含含氮物种，并通过电催化吸引增强了Au前驱体与载体的亲和力。纳米Au催化剂作为高性能催化剂，而N-rGO作为锚定催化剂的理想过滤材料。以4-硝基苯酚（4-NP）加氢作为模型催化反应，评估了所设计催化过滤器的催化活性。催化过滤器表现出优异的催化活性和出色的稳定性，通过单次通过催化过滤器即可轻松实现4-硝基苯酚的完全转化。由于明显改善了传质，所制备的催化过滤器性能优于传统的间歇式反应器。确定并优化了一些影响催化性能的关键操作参数。对于三种添加了4-硝基苯酚的实际水样（例如地表水、自来水和工业印染废水），也观察到了类似的催化性能。纳米Au催化剂的优异催化活性与二维且机械稳定的石墨烯相结合，使得能够合理设计各种用于潜在工业应用的连续流动催化膜。
