Interplay of Bubble Dynamics and Mass Transport in Porous TiO ₂ Photoelectrode for Enhanced Solar‐Driven Hydrogen Production

Photoelectrochemical cells (PECs) are the pivotal technology for solar‐driven water splitting, converting solar energy into hydrogen fuel. However, their efficiency is often hindered by two crucial challenges: mass transport limitations and bubble formation on the electrode surface. These bubbles obstruct active sites on the photoelectrode, reducing reaction efficiency and constraining hydrogen production. Our study seeks to enhance PEC efficiency by addressing these challenges through two primary strategies: mitigating mass transport limitations and simulating bubble dynamics using a computational approach. Titanium dioxide (TiO 2 ), a highly promising photoelectrode, is at the core of this research. By employing electrochemical anodization, we enhance the porosity of TiO 2 , which is essential for reducing the blockage of active sites caused by large gas bubbles that hamper the overall electrochemical reaction. Our study focuses on elucidating bubble nucleation, growth, and detachment, as these factors significantly influence the mass transport near electrode surface and overall efficiency of PEC system. By integrating computational simulations, we explored the interplay of factors such as bubble size distribution, detachment rate, and flow patterns, which affect the accessibility of reactant to the electrode. This approach highlights the critical role of TiO 2 porosity and bubble dynamics in improving PEC performance and advancing solar‐driven hydrogen production.