Effect of UV Irradiation on the Structural Variation of Metal Oxide-Silica Nanocomposites for Enhanced Removal of Erythromycin at Neutral pH

Abstract

In this study, the effect of UV treatment on the physicochemical properties and structural variation of metal oxide-silica nanocomposites (Mn2O3-Fe2O3@SiO2) has been investigated. Based on the results, UV irradiation significantly affects the nanocomposite structure, where SiO2 network reconfiguration, change in surface OH group density, and surface area were observed. Erythromycin (ERY) has been chosen as a module pollutant to compare the performance of the pristine and UV-treated nanocomposites. The pristine nanocomposite had a high adsorption efficiency (99.47%) and photocatalytic activity (99.57%) at neutral pH for ERY in the first cycle, and this efficiency decreased significantly for the multiple cycles. However, different results have been observed for the UV-treated nanocomposite, where it retained its performance for ten consecutive cycles. This enhanced performance is attributed to the structural modifications after UV exposure, where increased surface area, pore volume, and OH group density resulted in an increased number of the possible mechanisms responsible for the adsorption/oxidation of ERY. Moreover, oxidation of adsorbed molecules by UV light after each cycle can also be another reason for enhanced removal. For the first time, the fate of ERY is studied using regenerated nanocomposites after the last cycle. LC/MS/MS results showed that ERY degraded in 20 min, and the produced reaction by-products were adsorbed by nanocomposites. This study could be a foundation research for the practical approaches for the regeneration of nanomaterials and the successful removal of organic pollutants from aquatic environments.

Sustainable Removal of BTEX Gas Using Regenerated Metal Containing SiO2

“…The removal experiments were repeated in the same condition as the first cycle following the regeneration of the used nanocomposite with UV ( Figure 8 and Figure 9 ). Similar regeneration methods have been used in our previously published paper [ 29 ]. Both nanocomposites showed good reusability, revealing that the UV irradiation process is suitable for the regeneration method for metal-doped porous silica material.…”

“…Based on these results, it seems that the existing Si–O–Si bonds may have broken and been rearranged after UV irradiation, and a SiO 2 network with a higher content of OH groups has been formed, which can be one of the reasons for the high performance and reusability of both nanocomposites. In the adsorption process, these increased OH groups increase the number of hydrogen bonds between the oxygen of silanol groups with hydrogen molecules on BTEX and enhance the removal [ 29 ]. It should be noted that this finally brings more BTEX molecules into the nanocomposites’ vicinity and improves the possibility of degradation along with adsorption.…”

A Novel Metal-Containing Mesoporous Silica Composite for the Decolorization of Rhodamine B: Effect of Metal Content on Structure and Performance

“…A series of novel Mn x Fe y @SiO 2 (x,y = 1–20%) nanocomposites were synthesized for the first time via the sol-gel/combustion method with different content of precursors (Mn and Fe salts). The Mn x Fe y @SiO 2 nanocomposites were fabricated according to our previously published method with modifications in precursors and conditions [ 23 , 24 ]. Iron-Manganese containing amorphous silica (Mn x Fe y @SiO 2 ) was synthesized using the sol-gel/combustion technique at room temperature.…”

Effect of copper doping on the photocatalytic performance of Ni2O3@PC membrane composites in norfloxacin degradation

“…2 Owing to their pervasive use and environmental persistence, antibiotics have become emerging pollutants. 1,3 Various sources contribute to antibiotic pollution in the environment, with primary origins stemming from medical treatments, agricultural practices, livestock farming, and industrial production. 4 Notably, approximately 11.2 million kg of antibiotics are annually administered in livestock farming.…”