Ti/TiO2 nanotubes sensitized PbS quantum dots as photoelectrodes applied for decomposition of anticancer drugs under simulated solar energy

• Published in: Journal of hazardous materials Vol. 421; p. 126751
• Main Authors: Mazierski, Paweł, Wilczewska, Patrycja, Lisowski, Wojciech, Klimczuk, Tomasz, Białk-Bielińska, Anna, Zaleska-Medynska, Adriana, Siedlecka, Ewa M., Pieczyńska, Aleksandra
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.01.2022
• Subjects: Anticancer drugs; Ecotoxicity; PbS quantum dots; Photoelectrocatalysis; TiO2 nanotubes; Anticancer drugs; Photoelectrocatalysis; PbS quantum dots; TiO2 nanotubes; Ecotoxicity
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.126751

One of the challenges in research into photoelectrocatalytic (PEC) degradation of pollutants is finding the appropriate photoanode material, which has a significant impact on the process efficiency. Among all others, photoelectrodes based on an ordered TiO2 nanotube arrays are a promising material due to well-developed surface area and efficient charge separation. To increase the PEC activity of this material, the SILAR method was used to decorate Ti/TiO2 nanotubes by PbS quantum dots (QD). The ifosfamide (IF) degradation rate constants was twice as higher for PbS-Ti/TiO2 (0.0148 min−1) than for Ti/TiO2 (0.0072 min−1). Our research showed the highest efficiency of PEC degradation of drugs using IIIPbS-Ti/TiO2 made with 3 SILAR cycles (PbS QD size mainly 2–4 nm). The 4 and 6 of SILAR cycles resulted in the aggregation of PbS nanoparticles on the Ti/TiO2 surface and decreased IF PEC degradation rate to 0.0043 and 0.0033 min−1, respectively. Research on PEC mechanism has shown that the drugs are degraded mainly by the activity of photogenerated holes and hydroxyl radicals. In addition, the identified drug intermediates made possible to propose a degradation pathways of anticancer drugs and the ecotoxicity test show no inhibition of Lemna minor growth of treated solutions. [Display omitted] •PbS QDs increased PEC degradation efficiency of Ti/TiO2 photoelectrodes.•3 SILAR cycles allowed to obtain PbS nanoparticles of appropriate size (2-4 nm).•PbS QDs increase the absorbance in visible light and generate more active sites.•The PEC mechanism of drugs removal was based on direct and indirect holes activity.