【摘要】 以多孔轻木为原料,采用银氨溶液原位还原法在木材基体中负载金属Ag纳米催化剂,制备Ag/木材复合过滤材料,利用木材流体传输高效的特点和Ag纳米粒子的催化活性,实现对染料废水中有机污染物的催化降解。采用扫描电镜、透射电镜、X射线衍射仪对材料的形貌和结构进行表征,并考察负载纳米Ag木质过滤材料对有机染料亚甲基蓝的催化降解性能。结果表明:制备的Ag/木材复合过滤合材料保留了木材的孔隙结构,Ag纳米粒子成功负载在导管内壁且分布均匀,粒径范围5～20 nm;由于固定在导管内壁上的Ag纳米粒子的催化活性,木质过滤材料能有效催化降解水中的亚甲基蓝,其降解效率和水通量与过滤材料厚度密切相关;厚度为6mm的过滤材料在重力驱动下对亚甲基蓝的催化降解效率达94.03%,且水通量高达2 600 L/(m2·h),实现了染料降解效率与水通量的优化。负载纳米Ag木质过滤材料制备工艺简单、成本低廉、可规模化,在染料废水处理领域具有较好的应用前景。更多还原

【Abstract】 The extensive release of organic contaminants from the chemical industry has currently been a major source of water pollution.The development of low-cost,eco-friendly,and high-performance functional materials based on renewable resources for organic dye wastewater treatment are highly demanded.As a naturally growing porous structural material,wood consisting of numerous open microchannels along the growth direction may serve as a desirable scaffold for the development of efficient filtration materials for wastewater treatment.In this study,by in situ deposition of silver nanoparticles(Ag NPs) in the mesoporous structure of balsa wood,Ag/wood composite filters were developed for removing methylene blue(MB) from water,which was accomplished by the synergistic effects of the porous wood structure,providing high-speed channels for water transport and the catalytic activity of Ag NPs anchored to the surface of the wood channels.The as-prepared wood-based filters were characterized by the field-emission scanning electron microscopy,transmission electron microscopy and X-ray diffraction.The catalytic degradation performance of the Ag/wood composite filters for removing MB was investigated.The results showed that the porous structure of natural wood was well preserved after the decoration with Ag NPs,and the Ag NPs were uniformly distributed on the channel surfaces of wood vessels,with a size range of 5-20 nm.The Ag/wood composite filters could effectively remove MB(in the presence of NaBH4) from water during the filtration process due to the catalytic activity of Ag NPs anchored to the vessel channels,and the MB removal efficiency and water flux were highly dependent on the thickness of the wood-based filters.Specifically,the gravity-driven Ag/wood composite filter with a thickness of 6 mm showed desirable performance with a high MB degradation efficiency of 94.03% and a water flux of 2 600 L/(m~2·h).The proposed Ag-decorated wood-based filters have advantages of facile processing,low cost and scalability,displaying great potential for organic dye wastewater treatment.更多还原