Fabrication of multi-functional porous microspheres in a modular fashion for the detection, adsorption, and removal of pollutants in wastewater

Abstract Water pollution control has become significant challenges in recent years because of their extensive species diversity. It is critical to developing general-purpose materials for environmental rehabilitation. In this paper, a novel module-assembly method is developed to prepare multi-functional materials for treating pollutants in water. Building blocks are porous nanoparticles with a different function. Microspheres (MS) with a diameter of 90 μm are prepared and have a coefficient of variation of 6.8%. The modular fashion of self-assembly process in a microfluidic chip is the crucial factor in fabricating the multifunction material. The assembled microspheres with different building modules still have a specific surface area larger than 400 m 2 g −1 , and exhibit excellent performance in adsorbing various pollutants in water, such as heavy metal ions and organic dyes. The adsorption capacities of them to Hg 2+ and orange II reach 150 mg g −1 and 333 mg g −1 , respectively. The integrated fluorescence probes in microspheres can detect low concentration (9.8 ppb) of Hg 2+ . Microspheres integrated with Fe 3 O 4 nanoparticles have a magnetic susceptibility of 6.01 emu g −1 and can be easily removed from wastewater by applying an external magnetic. Due to the stability of inorganic building blocks, each function in the assembled system is well performed, and multi-functional “All-in-One” materials can be easily fabricated.