Integrating Pt@Ni(OH)2nanowire and Pt nanoparticle on C3N4with fast surface kinetics and charge transfer towards highly efficient photocatalytic water splitting.

• All-in-one Pt·Ni(OH) 2 /C 3 N 4 photocatalyst realizes one-step overall water splitting. • Pt·Ni(OH) 2 /C 3 N 4 achieves a prominent AQE of 4.2% at 420 nm and excellent stability. • Both H 2 O activation and charge transfer are dramatically enhanced. • The backward recombination of H 2 and O 2 is suppressed. Overall water splitting is vital in solar-hydrogen conversion. In addition to charge separation, the regulation of surface kinetics and suppression of backward reaction become particularly crucial. Herein, an all-in-one Pt·Ni(OH) 2 /C 3 N 4 photocatalyst is proposed by integrating Pt@Ni(OH) 2 composited nanowires and isolated Pt clusters on C 3 N 4. In this heterostructure, Pt@Ni(OH) 2 with rich coordinatively unsaturated sites effectively boost O 2 evolution, and Pt-O-Ni interaction retards O O bond cleavage thus inhibiting backward H 2 O regeneration. Meanwhile isolated Pt forms an Schottky junction with C 3 N 4 for electron transfer and proton reduction. Consequently, Pt·Ni(OH) 2 /C 3 N 4 achieves stoichiometric water splitting with H 2 /O 2 evolution of 1330/632 μmol g−1 h−1, and an outperforming AQE of 4.2% at 420 nm. Our work manifests that accelerating charge migration, inhibiting backward reaction and tuning surface kinetics are dominant in water splitting, for which a rational design of robust redox pathways is necessary. [ABSTRACT FROM AUTHOR]