Phthalocyanine-Grafted Titania Nanoparticles for Photodegradation of Ibuprofen

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.

Nipagin-Functionalized Porphyrazine and Phthalocyanine—Synthesis, Physicochemical Characterization and Toxicity Study after Deposition on Titanium Dioxide Nanoparticles P25

“…Finally, the interactions could consist in weak bonds between the photosensitizers and the unmodified surface of the nanoparticles, or the chemical groups present on their surfaces after functionalization, i.e., hydrophobic interactions with the long PEG chains [ 37 ]. In the presented study, titania nanoparticles with a plethora of hydroxyl surface groups were applied to influence their adsorption properties and enable the formation of hydrogen bonds [ 38 ]. The materials were prepared by depositing either 3 or 7 on the surface of TiO 2 nanoparticles.…”

Titanium Dioxide-Based Photocatalysts for Degradation of Emerging Contaminants including Pharmaceutical Pollutants

“…However, for this purpose, they need to be appropriately functionalized with functional groups that promote covalent binding to the surface of TiO 2 such as carboxylic or pyridyl groups [161]. According to the literature study, the effective energy transfer in the case of photosensitizer deposition through surface adsorption might not be efficient and the photosensitizer molecules need to be covalently bound to the surface of TiO 2 to sensitize the material toward visible light, at least when photodegradation in aqueous solution is considered [162].…”

“…In the study lately performed by our group, we have examined the photocatalytic properties of hybrid nanomaterials based on 5 nm and 15 nm anatase TiO 2 and metallophthalocyanines (Cu(II) and Zn(II)) [162]. Taking into consideration that the phthalocyanines did not have any functional groups that would allow for covalent binding to the surface of TiO 2 , we suspected that the mode of deposition on the surface was based on the adsorption and weak forces such as hydrogen bonding.…”

Oxidative Degradation of Pharmaceuticals: The Role of Tetrapyrrole-Based Catalysts

“…These semiconductor-promoted oxidation mechanisms are complementary to the ROS formation pathways mentioned above for the TPM-based catalysts and thus potentiate drug degradation. [1,13] Thus, a significant portion of the work developed in this field has been focused on the development of hybrid catalysts comprising TPM immobilized in semiconductors [2,[14][15][16][17][18][19][20][21][22].…”

“…•− ) are the main ROS species involved in IBU degradation. Mlynarczyk also investigated the IBU aqueous photodegradation in the presence of zinc(II) and copper(II) phthalocyanines (ZnPc and CuPc, respectively, Figure 6) embedded onto pure anatase-phase TiO 2 nanoparticles (ZnPc@TiO 2 and CuPc@TiO 2 ) [20]. Catalyst photoactivity was evaluated on a 10 mg/L solution of IBU in water by irradiating with three lasers (20 mW/cm 2 ) under either UV (365 nm) or visible light (665 nm) (Table 3, entry 4).…”