Photocatalytic Degradation of Fluoroquinolone Antibiotics in Solution

Abstract

The photocatalytic degradation of two quinolone-type antibiotics (ciprofloxacin and levofloxacin) in aqueous solution was studied, using catalysts based on ZnO nanoparticles, which were synthesized by a thermal procedure. The efficiency of ZnO was subsequently optimized by incorporating different co-catalysts of gC3N4, reduced graphene oxide and nanoparticles of gold. The catalysts were fully characterized by electron microscopy (TEM and SEM), XPS, XRD, Raman, and BET surface area. The most efficient catalyst was 10%Au@ZnONPs-3%rGO-3%gC3N4, allowing to obtain degradations of both pollutants above 96%. This catalyst has the largest specific area, and its activity has been related to a synergistic effect, involving factors as relevant as the surface of the material and the ability to absorb radiation in the visible region, mainly produced by the incorporation of rGO and gC3N4 to the semiconductor. The use of different scavengers during the catalytic process, was used to establish the possible photodegradation mechanism of both antibiotics.

State-of-the-art and challenges towards a Molecular Solar Thermal (MOST) energy storage device

“…Natural photosynthesis converts sunlight into stored chemical energy with an efficiency lying around the 3-6% mark. 6 In contrast, current artificial systems struggle to achieve similar efficiencies at comparable costs. [7][8][9][10] However, artificial photosynthesis can produce more dense energy fuels like methane, instead of the metabolites prepared by its natural counterpart.…”