Localized NiS2 Quantum Dots on g‐C3N4 Nanosheets for Efficient Photocatalytic Hydrogen Production from Water

Abstract Developing high‐efficiency yet low‐cost photocatalyst for solar hydrogen production by avoiding the use of noble metals has received adequate interest but remains a great challenge to date. This work reports a seed‐mediated hydrothermal approach for the synthesis of NiS 2 quantum dots (QDs) anchored two‐dimensional graphitic carbon nitride (g‐C 3 N 4 ) nanosheets. This hybrid shows superior performance toward photocatalytic H 2 evolution from water. The highest H 2 evolution rate reaches 4.841 μmol h −1 , with an apparent quantum efficiency of 2 % at 425 nm, which is even much higher than that of Pt‐modified g‐C 3 N 4 photocatalyst (2.865 μmol h −1 ). Moreover, the composite presents good stability without notable activity decay after several cycled tests. It is found that NiS 2 QDs are essential for this improvement. These small nanoclusters not only benefit rapid and vectorial diffusion of photogenerated electrons from g‐C 3 N 4 to NiS 2 , but also promote H 2 evolution by decreasing the thermodynamic overpotential for proton reduction. This work thus marks an important step toward designing good‐performance and low‐cost photocatalytic materials for solar H 2 conversion.