Enhancing the performance and antifouling properties of reverse osmosis membranes by graphene quantum dots for water desalination

Abstract

In the next decades, some countries will suffer from water shortage because of the increased population and the increased percentage of economic development. Accordingly, it is necessary to find the alternative way to solve this problem and investigate the development. Nanoscale graphene pieces known as graphene quantum dots (GQDs) exhibit distinctive characteristics that render them intriguing contenders for an array of novel uses. Cellulose acetate (CA) membranes were prepared from CA powder, formamide, and acetone with different concentrations of graphene quantum dots using the technique of phase inversion. The produced membranes were subjected to Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and contact angle studies to characterise their structural, morphological, hydrophilic, and biofouling behaviour. The graphene quantum dots additives proved to enhance the performance as well as antibiofouling characteristics of the CA-RO membranes. The CA membrane showed a flow of water 42.8 L/m² h and a 99.4% salt rejection rate using a 10,000 ppm NaCl solution after annealing.