Yang Sheng, Yuan Jing, Xie Pengpeng, Li Bo, Li Mengxuan, Zhou Daojin, Luo Liang, Sun Xiaoming
State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, China.
Nat Commun. 2025 Jul 1;16(1):5732. doi: 10.1038/s41467-025-61131-3.
To adapt fluctuating renewable energy for water splitting is challenging, since the growth of electrochemically generated nanobubbles at early stage requires high supersaturation during the repeated start-stop cycles, which can accelerate the deactivation of electrodes and cause extra energy consumption. Herein, we propose a "bubble seeding" strategy by introducing nanobubbles (NBs, ~200 nm in diameter) into electrolyte to promote the generation of macroscopic bubbles. The precursive nanobubbles can act as the beforehand nuclei with a certain supersaturation, lower the supersaturation barrier for further growth, and result in reduced overpotential as high as 130 mV for oxygen evolution reaction. The enhancement depends on nanobubble coverage and size, with higher coverage and larger sizes favoring macrobubble growth. The nanobubbles with inert gas species (e.g. N for oxygen evolution reaction) can also work as the seeds, while the interfering or consumable gas species (e.g. O for hydrogen evolution reaction) would hinder the generation of macroscopic bubbles and enlarge the overpotential. The water splitting device working at presence of nanobubbles exhibits stable operation voltage during repeated start-stop cycles in contrast to traditional electrolyte without NBs, indicating great potential of such traceless nanobubble additive strategy for stabilizing gas evolution applications.
将波动的可再生能源用于水分解具有挑战性，因为在反复的启停循环中，电化学产生的纳米气泡在早期阶段的生长需要高过饱和度，这会加速电极失活并导致额外的能量消耗。在此，我们提出一种“气泡播种”策略，通过将纳米气泡（直径约200纳米）引入电解液中来促进宏观气泡的产生。预先存在的纳米气泡可以作为具有一定过饱和度的预先核，降低进一步生长的过饱和度壁垒，并使析氧反应的过电位降低高达130毫伏。这种增强作用取决于纳米气泡的覆盖率和尺寸，覆盖率越高、尺寸越大越有利于宏观气泡的生长。含有惰性气体种类（例如用于析氧反应的氮气）的纳米气泡也可以作为种子，而干扰性或消耗性气体种类（例如用于析氢反应的氧气）会阻碍宏观气泡的产生并增大过电位。与没有纳米气泡的传统电解液相比，在纳米气泡存在下工作的水分解装置在反复的启停循环中表现出稳定的工作电压，这表明这种无痕纳米气泡添加剂策略在稳定气体析出应用方面具有巨大潜力。
