Transforming Red Phosphorus Photocatalysis: Dual Roles of Pre-Anchored Ru Single Atoms in Defect and Interface...

Crystalline red phosphorus (CRP), known for its promising photocatalytic properties, faces challenges in photocatalytic hydrogen evolution (PHE) due to undesired inherent charge deep trapping and recombination effects induced by defects. This study overcomes these limitations through an innovative strategy in integrating ruthenium single atoms (Ru₁) within CRP to simultaneously repair the intrinsic undesired vacancy defects and serve as the uniformly distributed anchoring sites for a controllable growth into ruthenium nanoparticles (Ru_NP). Hence, a highly functionalized CRP with Ru₁ and Ru_NP (Ru_1-NP/CRP) with concerted effects in regulating electronic structures and promoting interfacial charge transfer has been achieved. Advanced characterizations unveil the pioneering dual role of pre-anchored Ru₁ (analogous to the "Tai Chi" principle) in transforming CRP photocatalysis. The regulations of vacancy defects on the surface of CRP minimize the detrimental deep charge trapping, resulting in the prolonged lifetime of active charges. With the well-distributed in situ growth of Ru_NP on Ru₁ sites, the constructed robust "bridge" that connects CRP and Ru_NP facilitates constructive interfacial charge transfer. Ultimately, the synergistic effect induced by the pre-anchored Ru₁ endows Ru_1-NP/CRP with an exceptional PHE rate of 3175 μmol h^-1 g^-1, positioning it as one of the most efficient elemental-based photocatalysts available. This breakthrough underscores the crucial role of pre-anchoring metal single atoms at defect sites of catalysts in enhancing sustainable hydrogen production.