“Direct Injection” Bubble Growth Mediated by Nano‐Interfaced Electrodes for Efficient Chlorine Production

ABSTRACT The chlor‐alkali industry, with the chlorine evolution reaction (CER) as its core anodic process, accounts for nearly 4% of global electricity consumption. The development of energy‐efficient and stable CER system is therefore urgently needed. Nano‐interfaced electrodes exhibit superior catalytic performance, yet their mechanism for energy saving and system stability remains incompletely understood. Here, we combine a high‐speed camera and confocal laser scanning microscope Platform to visualize and digitalize the bubble evolution and the bubble‐induced overpotential ( ƞ bub ). We provide direct visual evidence that the bubble‐induced concentration gradients and fluid flow field disturbances are key regulators of overpotential, and that the nano‐interfaced electrode exhibits an ƞ bub of only approximately 49% of that of the flat‐interfaced electrode. Specifically, the nano interface not only generates a stronger interfacial electric field and enhanced bubble‐induced interfacial turbulence—which promote the Cl − migration to the electrode surface—but also induces a “direct‐injection” mode of bubble growth that mitigates the accumulation of reaction products near the electrode. Moreover, the Cl − enrichment capacity of the nano interface endows the near‐interface solution with ionic buffering capability, effectively suppressing potential fluctuations. This work demonstrates that regulating bubble dynamics is key to constructing energy‐saving and stable gas‐evolving electrochemical systems.