Accelerating photocatalytic hydrogen production by anchoring Pt single atoms on few-layer g-C3N4 nanosheets with Pt–N coordination

Abstract

Graphitic carbon nitride (g-C₃N₄) has gained considerable attention as a promising photocatalyst for hydrogen production through water splitting. However, its catalytic efficiency remains severely limited due to the rapid recombination of charge carriers and poor charge-transfer properties. Here, g-C₃N₄ is subjected to modification through the introduction of well-isolated Pt single atoms using a low-temperature incipient wetness impregnation method. The Pt single atoms exhibit a maximum weight ratio of 1.26%, resulting in a giant enhancement of the photocatalytic H₂ evolution rate (336.8 μmol h⁻¹), approximately two orders of magnitude higher than that of pristine g-C₃N₄ (1.8 μmol h⁻¹) during a 22-h-long test with an apparent quantum yield (AQY) of 13.5% at 405 nm. The improved performance and excellent stability in photocatalytic H₂ evolution can be attributed to the formation of Pt–N bonds between Pt single atoms and g-C₃N₄, which creates a new energy level of the N 2p–Pt 5d hybrid orbital for remarkably inhibiting the recombination of photogenerated electron–hole pairs and reducing interfacial charge-transfer resistance.