Renewable and eco-friendly ZnO immobilized onto dead sea sponge floating materials with dual practical aspects for enhanced photocatalysis and disinfection applications

Abstract

In this study, we have investigated the role of natural Dead Sea Sponge (DSS, Porifera) as a three- dimensional (3D) porous host substrate for the immobilization of nanostructured ZnO towards the development of floating photocatalysts for efficient removal of methylene blue (MB) dye under the illumination of sunlight. Since the treated water after dye degradation contains several pathogens, different disinfectants or chemical reagents are essentially used. This is not the case for DSS as it can naturally kill any pathogens during the wastewater treatment process. To explore these functions, ZnO nanosheets were incorporated onto DSS via hydrothermal protocol and the as prepared ZnO/DSS hybrid material exhibited ~100% degradation efficiency for the removal of MB. Importantly, the degradation kinetics associated with the fabricated ZnO/DSS was remarkably accelerated as evidenced by the high values of degradation reaction rate constants (3.35×10-2 min-1). The outperformance of ZnO/DSS could be attributed to the high rate of adsorption caused by its 3D porous structure together with the rapid oxidation of MB facilitated by the presence of silica (SiO2) within the composition, which acts as semiconducting photosensitive material. Furthermore, the high charge separation of electron-hole pairs, natural porosity, and abundant catalytic sites offered by the hybrid ZnO/DSS floating photocatalyst SiO2 play a major role in achieving ~100% degradation efficiency for MB. Finally, the excellent reusability results confirm the feasibility of using natural ZnO/DSS-based photocatalyst for practical solution of wastewater treatment and other environmental problems.

Metal–Organic Frameworks Marry Sponge: New Opportunities for Advanced Water Treatment

“…DSSs can adsorb dyes through their large pores and simultaneously exhibit antibacterial properties during wastewater treatment. 26 The efficacy of natural sponges as supportive carriers has been demonstrated, enabling the synthesis of MOFs on their surface and preventing MOF agglomeration. In addition, large porous channels generate channels from porous carbon brackets to promote the migration of solvent molecules and large-volume reactions and products.…”

“…Compared to synthetic counterparts, it offers advantages such as porosity and high antibacterial activity. DSSs can adsorb dyes through their large pores and simultaneously exhibit antibacterial properties during wastewater treatment . The efficacy of natural sponges as supportive carriers has been demonstrated, enabling the synthesis of MOFs on their surface and preventing MOF agglomeration.…”