Activating a Semiconductor–Liquid Junction via Laser‐Derived Dual Interfacial Layers for Boosted Photoelectrochemical Water Splitting

The semiconductor–liquid junction (SCLJ), the dominant place in photoelectrochemical (PEC) catalysis, determines the interfacial activity and stability of photoelectrodes, whcih directly affects the viability of PEC hydrogen generation. Though efforts dedicated in past decades, a challenge remains regarding creating a synchronously active and stable SCLJ, owing to the technical hurdles of simultaneously overlaying the two advantages. The present work demonstrates that creating an SCLJ with a unique configuration of the dual interfacial layers can yield BiVO4 photoanodes with synchronously boosted photoelectrochemical activity and operational stability, with values located at the top in the records of such photoelectrodes. The bespoke dual interfacial layers, accessed via grafting laser‐generated carbon dots with phenolic hydroxyl groups (LGCDs‐PHGs), are experimentally verified effective, not only in generating the uniform layer of LGCDs with covalent anchoring for inhibited photocorrosion, but also in activating, respectively, the charge separation and transfer in each layer for boosted charge‐carrier kinetics, resulting in FeNiOOH–LGCDs‐PHGs–MBVO photoanodes with a dual configuration with the photocurrent density of 6.08 mA cm−2 @ 1.23 VRHE, and operational stability up to 120 h @ 1.23 VRHE. Further work exploring LGCDs‐PHGs from catecholic molecules warrants the proposed strategy as being a universal alternative for addressing the interfacial charge‐carrier kinetics and operational stability of semiconductor photoelectrodes. Dual interfacial layers, composed of a top covalent anchored carbon dots layer and a Mo:BiVO4 shallow layer with enriched oxygen vacancies, are constructed to synchronously boost charge‐carrier kinetics and inhibit photocorrosion, which results in a BiVO4 photoanode with a photocurrent density of 6.08 mA cm−2, and operational stability up to 120 h at 1.23 VRHE.