Solar-driven photodegradation of ciprofloxacin and E. coli growth inhibition using a Tm3+ upconverting nanoparticle-based polymer composite

[Display omitted] •Solar irradiation of the nanocomposite allows the photogenerations of H2O2.•The nanocomposite is able to adsorb and concurrently photodegrade ciprofloxacin.•E. coli growth is inhibited by the nanocomposite under solar irradiation.•Upconverting nanoparticles do not leach from the polymer matrix. Solar-driven photocatalysis is of great interest in terms of a sustainable use of energy and its application in wastewater treatment. The UV light-driven photogeneration of H2O2 by solar irradiation is an advanced strategy for the treatment of bacteria and recalcitrant pollutants in wastewater, but suffers from low efficiencies. In this work, a solar-driven multifunctional nanocomposite consisting of Tm3+ upconverting nanoparticles, poly(vinyl alcohol), poly(acrylic acid) and hydroxylated sulfonated poly(ether ether ketone) was prepared. The components were crosslinked via a heating treatment at 170 °C, resulting in a non-leaching porous material. This nanocomposite exhibited excellent adsorption ability (89 % in 150 min) toward a 100 mg/L ciprofloxacin aqueous solution and proved to photodegrade it (50 %) upon 4 h artificial solar irradiation, exploiting photon upconversion processes. Moreover, an 80 % bactericidal effect against E. coli was registered upon sunlight irradiation. Altogether, these results suggest the feasibility of a solar-driven wastewater treatment based on upconverting nanoparticles.