Enhanced reverse osmosis performance of polyamide membranes by incorporating boron carbon nitride nanosheets

For the first time, this study explores the incorporation of boron carbon nitride nanosheets (BCN NSs) as novel two-dimensional (2D) nanofillers into the polyamide (PA) layer of thin-film composite (TFC) membranes, aiming to significantly enhance reverse osmosis (RO) performance. The synthesized thin-film nanocomposite (TFN) membranes were thoroughly characterized, revealing significant improvements in their morphological and physicochemical properties, including reduced PA layer thickness, enhanced hydrophilicity, increased negative surface charge, reduced roughness, and a higher cross-linking density. These improved characteristics led to remarkably enhanced water permeability and salt rejection performance of the TFN PA membrane. Additionally, the TFN membranes demonstrated enhanced antifouling and chlorine resistance properties. At an optimal BCN NSs loading of 0.03 wt%, the TFN membrane exhibited significantly enhanced RO performance, achieving a remarkable water permeance of 3.6 L·m⁻²·h⁻¹·bar⁻¹ (an 87 % increase over the pristine PA TFC membrane) alongside a superior NaCl rejection of 98.9 %. These findings underscore the significant potential of BCN NSs as an effective nanofiller for developing high-performance, robust, and durable RO membranes, marking a crucial step towards more efficient water desalination technologies.