Harnessing the photothermal effect of PDA-mediated plasmon Ag NPs to activate fluorinated BiVO4 for enhanced solar water oxidation

The efficiency of solar-driven water splitting has long been constrained by the poor utilization of the full-spectrum solar energy by semiconductors. This study leverages the localized photothermal effect of polydopamine (PDA)-mediated plasmonic Ag nanoparticles (NPs) to activate small-polaron hopping conduction in fluorinated BiVO 4 . This activation enhances light absorption and photoelectrochemical (PEC) performance. Experimental evidence indicates that fluorination optimizes both bulk properties and surface wettability. Concurrently, the PDA acts as a multifunctional interfacial layer, ensuring robust adhesion of Ag NPs and serving as an effective hole-transport medium. The synergistic photothermal effect of the intrinsic broadband absorption from PDA and the localized surface plasmon resonance (LSPR) from Ag NPs endows the photoanode with a photocurrent density of 4.96 mA cm −2 at 1.23 V RHE , photo-stability exceeding 10 h, and enhanced light-harvesting capability. Further mechanistic studies unveil that fluorination induces the elongation of local chemical bonds, facilitating reducing the reaction energy barrier. Notably, the loading of PDA@Ag photothermal layer introduces valence band tail states, which effectively narrow the bandgap and accelerate hole transfer. This work offers a novel paradigm for pioneering utilization of photothermal materials to convert thermal energy dissipation into a valuable resource for enhancing PEC performance.