High Efficiency Water Splitting Using Ultrasound Coupled to a BaTiO Nanofluid

To date, a number of studies have reported the use of vibrations coupled to ferroelectric materials for water splitting. However, producing a stable particle suspension for high efficiency and long-term stability remains a challenge. Here, the first report of the production of a nanofluidic BaTiO suspension containing a mixture of cubic and tetragonal phases that splits water under ultrasound is provided. The BaTiO particle size reduces from approximately 400 nm to approximately 150 nm during the application of ultrasound and the fine-scale nature of the particulates leads to the formation of a stable nanofluid consisting of BaTiO particles suspended as a nanofluid. Long-term testing demonstrates repeatable H evolution over 4 days with a continuous 24 h period of stable catalysis. A maximum rate of H evolution is found to be 270 mmol h g for a loading of 5 mg l of BaTiO in 10% MeOH/H O. This work indicates the potential of harnessing vibrations for water splitting in functional materials and is the first demonstration of exploiting a ferroelectric nanofluid for stable water splitting, which leads to the highest efficiency of piezoelectrically driven water splitting reported to date.