Developing innovative filtration membranes based on SiO2/TiO2/Cdot(N) nanoarchitectures for environmental applications

Abstract

This work describes the development of nylon filtration membranes modified with SiO₂/TiO₂/Cdot(N) nanostructures containing 0.25, 0.5, 1, and 2 % of TiO₂, which have been used to remove methylene blue, methyl orange, and bisphenol A from tap water. SiO₂/TiO₂/Cdot(N) nanostructures have been prepared by direct reaction of nitrogen-doped carbon quantum dots (Cdot(N)), titanium isopropoxide, and silica source. FTIR, SEM, EDS, and HR-TEM were used to characterize the different SiO₂/TiO₂/Cdot(N) nanostructures. The retention capacities of modified membranes were calculated using the standard addition method with UV spectroscopy at wavelengths of 275, 464, and 664 nm, exhibiting good retention capacities of 95 % for methylene blue, 96 % for methyl orange, and 97 % for bisphenol A per gram of sorbent. The nylon filtration membrane modified with SiO₂/0.5 %TiO₂/Cdot(N) nanostructures exhibits excellent performance in retaining these substances in a real water sample, surpassing both bare nylon and nylon modified with SiO₂/Cdot(N) in terms of retention capacity and mechanical stability. It can be used to avoid environmental contamination by these species from industrial wastewater.