Molecules interface engineering derived external electric field for effective charge separation in photoelectrocatalysis

Realizing efficient charge separation and transfer is a key challenge for solar energy conversion. Here, we proposed the creation of an external electric field (EEF) by molecules interface engineering with silane grafting to form strong positive electricity on surface in semiconductor photocatalyst, driving charge separation and transfer in both bulk and surface. Forced by the EEF, WO3nanoplates anchored silane molecules (WO3-SiH2NH2) for efficient photoelectrochemical (PEC) water oxidation shows 44.8% photocurrent enhancement. Interestingly, the photocurrent onset on WO3-SiH2NH2exhibited a 0.3V negative shift from 0.5 to 0.2 VRHEcompared with pure WO3caused by the change of band edge position. The strategy of creating EEF is proven effective using other semiconductors and opens up a potential application to construct numerous high performance photoelectrodes for water splitting.