Frequency controlled agglomeration of pt-nanoparticles in sonochemical synthesis

Henrik E Hansen; Frode Seland; Svein Sunde; Odne S Burheim; Bruno G Pollet

doi:10.1016/j.ultsonch.2022.105991

Frequency controlled agglomeration of pt-nanoparticles in sonochemical synthesis

Ultrason Sonochem. 2022 Apr:85:105991. doi: 10.1016/j.ultsonch.2022.105991. Epub 2022 Mar 31.

Authors

Henrik E Hansen¹, Frode Seland², Svein Sunde², Odne S Burheim³, Bruno G Pollet⁴

Affiliations

¹ Electrochemistry Group, Department of Materials Science and Engineering, Faculty of Natural Sciences, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway; Hydrogen Energy and Sonochemistry Research Group, Department of Energy and Process Engineering, Faculty of Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway. Electronic address: henrik.e.hansen@ntnu.no.
² Electrochemistry Group, Department of Materials Science and Engineering, Faculty of Natural Sciences, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.
³ Hydrogen Energy and Sonochemistry Research Group, Department of Energy and Process Engineering, Faculty of Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway.
⁴ Hydrogen Energy and Sonochemistry Research Group, Department of Energy and Process Engineering, Faculty of Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway; Green H(2) Lab, Pollet Research Group, Hydrogen Research Institute (HRI), Université Du Québec à Trois-Rivières (UQTR), 3351 Boulevard des Forges, Trois-Rivières, Québec G9A 5H7, Canada.

Abstract

Optimizing the surface area of nanoparticles is key to achieving high catalytic activities for electrochemical energy conversion devices. In this work, the frequency range (200 kHz-500 kHz) for maximum sonochemical radical formation was investigated for the sonochemical synthesis of Pt-nanoparticles to assess whether an optimum frequency exists or if the entire range provides reproducible particle properties. Through physical and electrochemical characterization, it was found that the frequency dependent mechanical effects of ultrasound resulted in smaller, more open agglomerates at lower frequencies with agglomerate sizes of (238 ± 4) nm at 210 kHz compared to (274 ± 2) nm at 326 kHz, and electrochemical surface areas of (12.4 ± 0.9) m²g^-1 at 210 kHz compared to (3.4 ± 0.5) m²g^-1 at 326 kHz. However, the primary particle size (2.1 nm) and the catalytic activity towards hydrogen evolution, (19 ± 2) mV at 10mA cm²,remained unchanged over the entire frequency range. Highly reproducible Pt-nanoparticles are therefore easily attainable within a broad range of ultrasonic frequencies for the sonochemical synthesis route.

Keywords: Electrocatalyst; Frequency; Hydrogen; Platinum; Sonochemistry; Ultrasound.

MeSH terms

Catalysis
Nanoparticles* / chemistry
Particle Size