Abstract
Photoelectrocatalysis has attracted significant attention for water splitting and contaminant degradation. However, the lifetime of photoelectrocatalysis devices is hampered by the severe instability and photocorrosion of the photo-active nanomaterial on the photoelectrode, which is a key limitation to realizing industrialization. Typically, the conventional protection strategy of photoelectrodes usually suffers from the trade-off between the photoelectrocatalytic activity and stability. Inspired by biological cell membrane with water channels, here a highly permeable and ultrathin silica coating with ultrasmall straight nanochannels is in situ grown that stabilizes the photoelectrode. These ultrasmall channels boost photoelectrocatalysis by accelerating water transport and reducing the reaction energy within the confined nanochannels. Specifically, the ultrathin coating imparts significant mechanical and structural stability to the photo-active nanomaterial, thereby preventing its detachment, dissolution, and crystal damage without compromising performance. As a result, the protected photoelectrode exhibits enhanced water splitting activity and excellent stability over 120 h, whereas the photocurrent of the unprotected photoelectrode degrades rapidly. Meanwhile, the coated photoelectrode also exhibits superior photoelectrocatalytic degradation efficiency (>97%), even after the 10th cycle. This strategy is facile and universal and can be extended to construct other stable and high-performance electrodes for promoting photoelectrocatalysis in practical applications.