Ag-TiO2 Assisted Photocatalytic Degradation of Cytostatic Drug Cyclophosphamide Under UV-VIS Light

Abstract

Cyclophosphamide (CP) is a commonly prescribed cytostatic drug that has cytotoxic, genotoxic, mutagenic, carcinogenic and teratogenic effects on living organisms, which asks for its elimination from any water source. The photocatalytic degradation of CP under UV-VIS irradiation was studied, using non-doped TiO2 and Ag- doped TiO2 (0.5-1.7% wt.). The catalysts were synthesized by vacuum deposition method. The influence of Ag concentration on the degradation performance of CP was investigated and an optimal content of 1.0% Ag was established. Using of this catalyst assures the pollutant degradation with a rate constant kCP = 6.59 x 10-4 s-1 and an efficiency ηCP = 99% after120 min irradiation time. Based on the results of the quenching experiments in the presence of suitable scavengers, a mechanism of photocatalytic degradation of CP has been proposed. This consists in the attack of free hydroxyl radicals and superoxide radicals on the pollutant. Also, the contribution of Ag to inhibition of charge recombination and the additional generation of superoxide radicals, which are responsible for the higher photocatalytic activity of Ag doped TiO2 compared to non-doped TiO2, was emphasised.

Photodegradation of 2,4-D (dichlorophenoxyacetic acid) with Rh/TiO2; comparative study with other noble metals (Ru, Pt, and Au)

“…Scavenger experiments were benzoquinone (BQ, superoxide anions O 2− ), isopropanol (IPA, ˙OH radicals), ethylenediaminetetraacetic acid (EDTA, h + hole trapping) and potassium dichromate (K 2 Cr 2 O 7 , e − ). 80,81 Fig. 13 shows the results of the apparent kinetic constant after the addition of scavengers, where a decrease of 83 and 63% was obtained with IPA and BQ, respectively.…”

Anticancer drugs in the environment: environmental levels and technological challenges

“…Physicochemical treatment comprises membrane filtration processes (Cristo ´va ˜o et al, 2019;Verliefde et al, 2007;Wang et al, 2009) and advanced oxidation processes (AOPs). The AOPS can be further subdivided into UV-based photodegradation treatments such as photolysis (UV) (Buerge et al, 2006;Franquet-Griell et al, 2017a;González-Burciaga et al, 2020;Governo et al, 2017;Guo et al, 2015;Janssens et al, 2019;Kovalova et al, 2013;Lin et al, 2013;Lutterbeck et al, 2016;Zhang & Lim, 2020;Zhang et al, 2017a); photooxidation treatments (UV-H 2 O 2 ; UV-Cl, UV-Na 2 S 2 O 8 ) (Akbari & Adibzadeh, 2020;Franquet-Griell et al, 2017a;González-Burciaga et al, 2020;Janssens et al, 2019;Lee et al, 2021;Lester et al, 2011;Lutterbeck et al, 2015a;Lutterbeck et al, 2015b;Lutterbeck et al, 2015c;Tang et al, 2020;Zhang et al, 2017a;Zhang et al, 2017b) and photocatalytic oxidation treatments (UV-TiO 2 , UV-BiOCl n Br m , UV-BiOClBr, UV-Fenton's reagent) (Borzyszkowska et al, 2016;Chatzimpaloglou et al, 2021;Cristea Ionut, Arcadie, Constantin Lucian, Constantin Mirela, & Nitoi, 2020;Governo, Santos, Alves, & Madeira, 2017;Janssens et al, 2019;Koltsakidou et al, 2017;Kovalova et al, 2013;Lai, Lin, & Lin, 2015;Lin & Lin, 2014;Lutterbeck et al, 2015c;Lutt...…”

“…UV/Ag-TiO 2 uses Ag as an additional generator of superoxide radicals to degrade pollutants, allowed a removal efficiency of 99% for cyclophosphamide from Milli-Q water (Cristea Ionut et al, 2020).…”