Enhanced photoelectrochemical degradation of Ibuprofen and generation of hydrogen via BiOI-deposited TiO2 nanotube arrays

Abstract

This study employed BiOI-deposited TiO2 nanotube arrays (BiOI-TNTAs) electrode in a photoelectrochemical (PEC) system to oxidize Ibuprofen and generate hydrogen in the anodic and cathodic chamber, respectively. FESEM results revealed the diameter of TiO2 nanotubes was 90–110nm. According to the XRD analysis, the BiOI-TNTAs were dominated by the anatase phase and tetragonal structure of BiOI. XPS results confirmed the coexistence of BiOI in the BiOI-TNTAs associated with Bi (33.76%) and I (8.81%). UV–vis absorption spectra illustrated BiOI-TNTAs exhibit strong absorptions in the visible light region. The PEC method showed the best degradation efficiency for Ibuprofen is a rate constant of 3.21×10−2min−1. The results of the Nyquist plot revealed the recombination of photogenerated electron-hole pairs was inhibited as the bias potential was applied. Furthermore, the Bode plot demonstrated the lifetime (τel) of photoexcited electrons of BiOI-TNTAs was 1.8 and 4.1 times longer than that of BiOI-Ti and TNTAs, respectively. In the cathodic chamber, the amount of hydrogen generation reached 219.94μM/cm2 after 3h of reaction time.