Phthalocyanine-Grafted Titania Nanoparticles for Photodegradation of Ibuprofen

Rafal Krakowiak,Marek Sikorski,Wioletta Bendzinska-Berus,Marcin Spychala,Joanna Musial,Robert Frankowski,Ryszard Krzyminiewski,Dariusz T Mlynarczyk,Tomasz Goslinski,Agnieszka Zgoła-Grześkowiak,Jadwiga Mielcarek,Ryszard Blazejewski,Bernadeta Dobosz,Ewa Tykarska,Beata J Stanisz

doi:10.3390/catal10111328

Abstract

The natural environment is constantly under threat from man-made pollution. More and more pharmaceuticals are recognized as emerging pollutants due to their growing concentration in the environment. One such chemical is ibuprofen which has been detected in processed sewage. The ineffectiveness of water methods treatment currently used raises the need for new remediation techniques, one of such is photodegradation of pollutants. In the present study, zinc(II) and copper(II) phthalocyanines were grafted onto pure anatase TiO2 nanoparticles (5 and 15 nm) to form photocatalysts for photodecomposition of ibuprofen in water. The nanoparticles were subjected to physicochemical characterization, including: thermogravimetric analysis, X-ray powder diffraction, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface area analysis and particle size measurements. In addition, they were assessed by means of electron spin resonance spectroscopy to evaluate the free radical generation. The materials were also tested for their photocatalytic activity under either UV (365 nm) or visible light (665 nm) irradiation. After 6 h of irradiation, almost complete removal of ibuprofen under UV light was observed, as assessed by liquid chromatography coupled to mass spectrometry. The reaction kinetics calculations revealed that the copper(II) phthalocyanine-containing nanoparticles were acting at a faster rate than those with zinc(II) derivative. The solutions after the photoremediation experiments were subjected to Microtox® acute toxicity analysis.

Highlights

The natural environment all around the globe is constantly deteriorating due to human activity
The researched phthalocyanines were chosen according to their high photoactivity—ZnPc [32,33] and earlier reported effectiveness in photoremediation—CuPc [22,31,34]
Materials based on pure anatase titania nanoparticles and phthalocyanines were prepared by a chemical deposition method, as well as carefully analyzed by thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD), X-ray photoelectron spectroscopy (XPS), particle size measurements and electronspin spinresonance resonance (ESR)

Summary

Introduction

The natural environment all around the globe is constantly deteriorating due to human activity. With the constant development of our civilization and growing industrialization, we are facing new problems within our environment. They concern an improper utilization of chemical contaminants, including industrial wastes, pharmaceuticals and cosmetics [3]. When deposited in the ground, these wastes can travel and end up in water reservoirs spreading toxicity and endangering human health. This is an issue of grave importance given that technology employed in contemporary water treatment facilities cannot effectively remove all of the substances belonging to this broad group [4]

Methods

Results

Conclusion