Ultrasound-driven seawater splitting catalysed by TiO2 for hydrogen production

Journal article

Seawater splitting presents a promising approach for sustainable hydrogen production, yet its application remains limited by competing side reactions and expensive catalyst in electrolysis. In this study, we present an alternative hydrogen production approach using ultrasonic-driven seawater splitting catalysed by TiO2 at room temperature. The application of high-frequency ultrasound (780 kHz, 5.1 W) with a bespoke sonoreactor, designed to focus pulsed ultrasound waves, induces inertial cavitation and generates highly reactive radicals to produce hydrogen. By optimising acoustic parameters and TiO2 catalyst concentration of 0.3 mg/mL, the system achieved the highest reported sonochemical efficiency for hydrogen production in both pure and natural seawater, reaching 8086 and 4210 μmol gcat−1 L−1 Whr−1, respectively. We further investigated the significant decrease in hydrogen production in salty environments. Through bubble dynamics simulations and electron paramagnetic resonance measurements, we attributed the salt-scavenging chemical effect has a dominant role in reducing the efficiency. Our findings demonstrate the potential of sonocatalytic seawater splitting with TiO2 as a viable alternative for renewable hydrogen production.

Authors: Wong, CCY; Preso, DB; Qin, Y; Sinhmar, PS; Zong, Z

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: International Journal of Hydrogen Energy
• Volume: 111
• Pages: 723-734
• Publication date: 2025-02-27
• Acceptance date: 2025-02-20
• DOI: 10.1016/j.ijhydene.2025.02.327
• EISSN: 1879-3487
• ISSN: 0360-3199
• Language: English
• Keywords: biomedical imaging; hydrogen production; sonochemistry; sonocatalysis; green hydrogen; seawater splitting