A recyclable indoor air filter system based on a photocatalytic metal–organic framework for the removal of harmful volatile organic compounds

Adsorption/removal of volatile organic compounds (VOCs) has become essential for indoor air quality management because of their harmful effect on the human body. In this study, we report on an indoor VOC filter system using a photocatalytic metalorganic framework (MOF) filter (PMF) based on MIL-100(Fe) with a particle size of ∼ 160 nm. The PMF was prepared by the electrophoretic deposition of MOF nanoparticles on a porous nickel foam. The MOF nanoparticles were uniformly coated on a large-sized conductive Nickel foam (up to a 10 cm diameter) without uncoated metal foam. To evaluate the adsorption/removal performance of VOCs on the developed PMF, a testbed system, including a photoionization detector, a carbon dioxide sensor, an ultraviolet (UV) light-emitting diode module, and a fan module, was developed, and a filter system was set up. The fabricated PMF showed excellent adsorption and decomposition of the adsorbed VOCs under UV light due to the high specific surface area and photocatalytic property of MIL-100(Fe). The average adsorption and removal performances of the PMF for 10 experiments were 94.25% and 75.95%, respectively. In the durability test, the PMF indicated 72.65% removal efficiency after conducting recycling tests 50 times, and the structure of the PMF was stable. Our approach provides an easy method for preparing MOF-based photocatalytic filters for use in an indoor VOC purification system. We believe that the prepared PMF has good stability and durability for VOC removal and can be applied to various applications such as home, automobile, office, and industry.