Sunlight-assisted electrochemical performance of vertical self-standing cerium-oxide nanoflakes decorated lead-oxide electrode for methylene blue removal

Abstract

This study demonstrates the effects of vertically self-standing cerium-oxide nanoflakes (CeO2NF) coated on lead-oxide battery electrode (LBE) as anode material CeO2NF/LBE used in sunlight assisted electrochemical oxidation (EO) process of methylene blue (MB) in the aqueous phase. In this study, commercial LBE is modified with CeO2NF via the hydrothermal deposition method, and surface morphology is examined through Field emission scanning electron microscopy and energy dispersive adsorption spectroscopy to the self-standing assembly of CeO2[sbnd]NF on the LBE surface. X-ray diffraction analysis identifies different crystalline phases of CeO2 and PbO2 of metal-oxide in modified LBE. Unique assembly offered high electrochemical surface area during the EO process. At different hydrothermal synthesis conditions like Ce-nitrate concentration, hydrothermal retention time (HRT), CeO2NF/LBE, CeO2NF-1, CeO2NF-2, CeO2NF-3, and CeO2NF-4 materials are synthesized and tested as an anode in EO for MB removal. Based on high MB removal of CeO2NF/LBE, hydrothermal synthesis conditions (Ce-nitrate:0.05 M and HRT: 2 h) are optimized. Furthermore, in the presence of sunlight, a comparative high MB removal performance of CeO2NF/LBE anode material during the EO test is found as compared to without sunlight. In the case of sunlight assisting under other identical EO process conditions, the MB removal efficiency of 96% and 90% was attained in 240 min in the presence and absence of sunlight, respectively. The synthesized electrode also showed excellent stability for 17 h under severe oxidizing conditions, and it can be used up to 8 times without any significant loss in removal efficiency. © 2023 Elsevier Ltd