BARDS analysis of real-time H2 and O2 gas evolution during the total water splitting of an aqueous electrolyte

Abstract

Hydrogen fuel cell technology has the potential for integration with renewable energy sources to produce electricity without the need for fossil fuels and thus reducing greenhouse gas emissions. A downside to the use of fuel cells is the electrodes used in the production of hydrogen gas are typically made from expensive inert metals such as platinum. Efforts are being made in producing cheap and effective electrodes from new materials to make hydrogen production more efficient. Gas evolution requires an accurate analysis of electrochemical behaviour of electrodes to quantify efficiency, improvement, or stability.

A new approach to track electrochemical water splitting through gas volume evolution from hydrogen and oxygen evolution processes is developed, taking inspiration from existing Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) analytical technique. The BARDS technique observes the change in the resonance frequency of a solvent when a solute is added to the solution. This change in frequency occurs due to the formation of gas bubbles during dissolution. This same phenomenon is observed during electrolysis of a specific solvent. Real-time tracking of these frequency changes was gauged and produced unique acoustic profiles. These acoustic profiles were assessed in terms of electrolyte used, the concentration of the electrolyte, and the potential applied to the electrolyte. The technique could be utilised in the future evaluation of newly made electrode materials that evolve hydrogen gas and correlate material electrochemistry to the actual gas volume evolved in real-time.