Dual-Functional Porous Wood Filter for Simultaneous Oil/Water Separation and Organic Pollutant Removal

High-performance functional materials capable of simultaneously separating oil from water and removing water-soluble contaminants are critically demanded for wastewater treatment but remain highly challenging. Wood, a naturally occurring porous material composed of numerous open microchannels along the growth direction, may serve as a desirable scaffold for the development of efficient filtration materials for water treatment. Herein, by in situ deposition of silver nanoparticles (Ag NPs) within the channels of balsa wood, we developed dual-functional Ag/wood filters for simultaneous oil/water separation and organic dye removal from water in a one-step process. Owing to their superhydrophilicity and underwater superoleophobicity, the as-prepared Ag/wood filters can selectively separate water from oil with a high efficiency (∼99%). Moreover, benefiting from the catalytic activity of Ag NPs anchored to the surface of the wood channels, the Ag/wood filters effectively removed methylene blue (MB) from water during the oil/water separation process; the MB removal efficiency was highly dependent on the thickness of the wood filters. Specifically, the gravity-driven separation using a 6 mm-thick Ag/wood filter showed a high MB degradation efficiency of 94.03% and a water flux of 2600 L·m^-2·h^-1. The proposed wood-based filtration material features renewable, inexpensive raw materials, facile processing, and scale-up potential. Such dual-functional Ag/wood filters capable of rapid and efficient removal of insoluble oils and soluble pollutants from water in a one-step process offer a promising solution for wastewater treatment.