INVESTIGATING THE ROLE OF QUANTUM CONFINEMENT AND SURFACE PLASMON RESONANCE IN ENHANCING WATER PURIFICATION EFFICIENCY OF NANOMATERIAL-BASED MEMBRANES

Abstract

Wastewater pollution is prevalent worldwide, and therefore, there is a need to come up with proper purification methods. There are also problems of membrane fouling, high energy costs compared to conventional treatments, and inapplicable to many pollutants of the currently available technologies like reverse osmosis and activated carbon adsorption. Newer innovations that have been adopted in nanotechnology include the quantum confinement and the surface plasmon resonance which is useful for the purification of water in nanomaterial-based membranes. This paper investigates the synthesis of quantum-confined TiO₂ and ZnO QDs embedded in Au and Ag NPs to facilitate quantum confinement effects and SPR to enhance contaminant reduction abilities. Quantum confinement improves photoactivity by increasing band gap energy, which enables efficient photodegradation of the organic pollution through UV light exposure. At the same time, SPR in noble metal nanoparticles boosts light absorption in the visible region and enhances photocatalytic reactions through hot electrons injection and locally enhanced electromagnetic field. The developed nanomaterial containing membranes were comprehensively characterized and evaluated for the water permeability, the degradation of pollutants, adsorption of heavy metal ions, antimicrobial activity, and fouling behavior. The findings revealed that the incorporation of TiO₂ and ZnO QDs in the membranes remove 88-92% of the organic dyes and pharmaceutical compounds in the water while, Au and Ag nanoparticles help in the inactivation of bacterial by more than 95% and eliminations of Pb²⁺, As³⁺ and Cd²⁺up to 90%. Moreover, the SPR-based membranes had a higher water flux of 135 L/m²h and a better anti-fouling characteristic to enable long-term stable operation. These findings highlight the possibilities of achieving synergistic effects of integrated cooperation and training and development efforts.