Preparation and Performance of a Boron Nitride Nanotube-Based Radon Capture Filter

Abstract: Radon (Rn), a ubiquitous radioactive gas, is the second leading cause of lung cancer in humans.Developing efficient and highly adaptable radon-adsorbing materials therefore carries significant implications for radiation protection and public health. To address the deficiencies commonly associated with conventional radon adsorbents-high humidity sensitivity, poor radiation stability, and rigid architectures that cannot conform to complex curved surfaces-this study proposes a novel flexible, filter-type radon capture material based on boron nitride nanotubes (BNNTs). Using a flexible stainless-steel wire mesh as the substrate, a BNNT-based radon capture filter (BNRCF) was successfully prepared by a grinding-mixing and high-temperature annealing route, in which the precursor was annealed at 1260 °C for 3 h under an ammonia (NH 3 ) atmosphere. Scanning electron microscope (SEM) indicated that the filter surface transformed from a loose, needle-like morphology before radon adsorption into a dense, flocculent structure afterwards. Energy-dispersive X-ray spectroscopy (EDS) elemental mapping clearly detected radon and its progeny, confirming that they were effectively captured and retained. In addition, the water contact angle of the filter reached 152.49°, demonstrating pronounced superhydrophobicity. Dynamic radon adsorption experiments further showed that the BNRCF exhibit certain adsorption performance under different numbers of layers, with a stable adsorption behavior and maximum efficiency of 15.2%. Overall, the superhydrophobicity, radiation stability and flexibility of the BNRCF highlight its application potential in the field of radon adsorption.