Deposition of CeO2 on TiO2 nanorods electrode by dielectric barrier discharge plasma to enhance the photoelectrochemical performance in high chloride salt system

In this study, cerium oxide (CeO2) was deposited on TiO2 nanorods (TiO2-NRs) through the one-step deposition by using dielectric barrier discharge (DBD) plasma treatment, where this was a simple and efficient means of synthesizing a CeO2/TiO2-NR electrode. The results of X-ray diffraction indicated that CeO2 (1 1 1) was successfully loaded on the TiO2-NRs, and the peak shifted in the positive direction after DBD discharge-induced modification, indicating that a bond between CeO2 and TiO2 had been formed in the CeO2/TiO2-NR electrode. Based on X-ray photoelectron spectroscopy, the ratio of Ce3+/Ce4+ increased due to plasma modification to enhance the oxygen vacancy of the CeO2/TiO2-NRs in the lattice structure. The CeO2/TiO2-NR composite electrode delivered the best photoelectrochemical (PEC) performance at a modified input voltage of 45 V and a deposition time of 10 min due to DBD discharge. The efficiency of removal of phenol from simulated seawater with a high salt system yielded the highest value of 97.1% for the CeO2/TiO2-NR electrodes through the PEC process at 3 V and UV-visible irradiation. A mechanism of the PEC performance of the CeO2/TiO2-NRs electrode was proposed, whereby a heterojunction was formed between TiO2 and CeO2 to increase the effect of oxygen storage, and active chlorine ions were produced in the high chloride salt system to enhance the degradation of pollutants.

Automated summary

In this study, CeO2 was deposited on TiO2-NRs through DBD plasma treatment, forming a CeO2/TiO2-NR electrode. The composite electrode showed excellent PEC performance under specific conditions, and could effectively remove phenol from simulated seawater.