Ti/TiO 2 nanotubes sensitized PbS quantum dots as photoelectrodes applied for decomposition of anticancer drugs under simulated solar energy.

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 TiO ₂ 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/TiO ₂ nanotubes by PbS quantum dots (QD). The ifosfamide (IF) degradation rate constants was twice as higher for PbS-Ti/TiO ₂ (0.0148 min ^-1 ) than for Ti/TiO ₂ (0.0072 min ^-1 ). Our research showed the highest efficiency of PEC degradation of drugs using IIIPbS-Ti/TiO ₂ 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/TiO ₂ 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.
(Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)