A new study has developed revolutionary methods to address the inefficiencies faced by electrocatalytic processes, particularly during hydrogen evolution reactions, by manipulating the behavior of nanobubbles formed on catalyst surfaces. This research, which utilizes advanced microscopy techniques, demonstrates how controlling nanobubble nucleation can significantly improve the efficiency of hydrogen production.
Electrocatalytic gas-evolving reactions often result in surfaces becoming covered with bubbles, which hinder the mass transfer to active sites, particularly under high current density conditions. Such blockage can lead to sudden failures of electrochemical cells, as explained by the study published on March 16, 2025, by a team of researchers led by Zhang, Liu, and Guo.
To overcome these challenges, the research team developed an on-chip microcell-based total-internal-reflection-fluorescence microscopy platform. This method enables dynamic imaging of bubble nucleation at resolutions down to 50 nanometers during the hydrogen evolution reaction. They utilized platinum and interfacial metal layers on graphene as model systems, observing how different configurations influenced bubble behavior and overall catalytic activity.
Importantly, the study revealed the concept of delocalized nanobubble evolution (DNE), where significant numbers of bubbles formed on the graphene support instead of just on the active platinum surface. This separation process was made possible by the introduction of interfacial metal layers, such as titanium, which enhanced electron transfer and significantly decreased the kinetic barriers for hydrogen migration from platinum to graphene. "Using our on-chip-TIRF platform, we were able to capture how nanobubbles behave dynamically at the interface during electrochemical reactions," said the research team.
The team demonstrated compelling evidence of improved catalytic activity through both microcell and polymer electrolyte membrane cell experiments. The results showed how controlling bubble nucleation could increase the effective electrocatalytic area and improve mass transport, yielding performance metrics far exceeding traditional methods.
Historically, advances have concentrated on refining the structural capabilities of solid catalysts and modulating electrolyte conditions, leaving the gas phase phenomena relatively unexplored. This comprehensive approach heralds new strategies for enhancing hydrogen production, especially as the global demand for sustainable energy sources rises.
The researchers anticipate their discoveries will have broad applications, particularly as the world moves toward greener energy solutions like hydrogen fuel. By minimizing gas-induced mass transport resistance at operating cells, this study offers potent insights for designing future electrocatalytic interfaces.
These advances provide optimism for addressing significant obstacles facing clean hydrogen production. "Our findings reveal the potential of modulating bubble nucleation to significantly boost the performance metrics for hydrogen production," Zhang and his colleagues concluded, highlighting the transformative impact of this research initiative.