Is porous boron nitride suited for water treatment? – a critical perspective on the materials water stability

Abstract

Treatment of wastewater from organic and inorganic pollutants is an important process to secure access to clean drinking water in the future. A simple and cost-effective method to ensure the removal of trace contaminants is their adsorption with porous materials. Recent adsorption studies indicate that porous boron nitride (PBN) could remove pollutants like dyes, antibiotics, and metal ions very effectively due to its high surface area and partially ionic polar bond type, which greatly promotes interactions between the material and pollutants. Furthermore, these studies suggest good regeneration and high cycle stability of the PBNs. However, research on the water stability of PBN depicts extremely low hydrolytic stability and rapid decomposition in the presence of water. Here, multiple studies suggest that highly porous and defect rich BN is unsuited for applications in water. In order to understand this contradiction, a detailed literature review on the application of PBN in wastewater treatment and the materials hydrolytic stability is performed. Key properties of PBN for water treatment are identified and discussed critically in regard to its effect on stability. This correlation reveals clear gaps and new questions in the current research and provides new suggestions for future investigations.