Morphologies dependence of hydrogen evolution over CeO2 via ultrasonic triggering

Ultrasonic field can lead to cavitation bubbles explosion, which rises a high-frequency oscillation and generates a high-frequency current in semiconductor nanoparticles in suspension. However, the effect of nanoparticle morphology on ultrasonic-triggered H-2 production is still unclear. To this end, herein, nanorods CeO2 (nrCeO2), CeO2 nanocubes (ncCeO(2)), and CeO2 nanospheres (nsCeO(2)) were successfully synthesized. Among them, one-dimensional nrCeO(2) had the most abundant O-vacancies. As revealed by the COMSOL simulation, nanoparticle deformation was easier in nanorods compared with nanocubes and nanospheres, resulting in more efficient charge separation and facilitating H-2 production reaction in nrCeO(2). In detail, within a 5 h' period, nrCeO(2) presented the highest H-2 production activity of 983.1 mmol g(-1) h(-1) with the positive charge (q+) trapping agent of CH3OH, and that of 278.1 mmol g(-1) h(-1) in pure water. This work presents a new understanding about the relationship between nanoparticle morphology and H-2 production activity, and provides a promising, efficient, and clean H-2 production approach, which can be further extended to multi-field coupling reactor.(C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.