Ta3N5 nanorods encapsulated into 3D hydrangea-like MoS2 for enhanced photocatalytic hydrogen evolution under visible light irradiation

Abstract

Tantalum nitride (Ta₃N₅) with an appealing band gap (∼2.1 eV) has emerged as a promising catalyst in the photocatalysis field. However, Ta₃N₅ application in the photocatalytic hydrogen evolution reaction (HER) is limited due to disadvantages such as unsatisfactory separation and transfer of photogenerated carriers. Here we utilize MoS₂ as co-catalysts to promote the kinetics of photocatalytic H₂ evolution over Ta₃N₅. The Ta₃N₅ nanorods were encapsulated into 3D hydrangea-like MoS₂ for maximizing the contact areas between Ta₃N₅ and MoS₂ and offering rich active sites. More importantly, spectroscopic analysis and theoretical calculations consistently reveal that the unique interfacial interaction, as well as the matching band alignment between Ta₃N₅ and MoS₂, accelerates the photogenerated charge extraction from Ta₃N₅ to MoS₂, reducing charge recombination losses in Ta₃N₅. Thus, the optimized Ta₃N₅/MoS₂ hybrid exhibits a substantially enhanced hydrogen evolution rate (56.5 μmol h⁻¹), over 22 times higher than that of pristine Ta₃N₅. This work may provide a general strategy to overcome the low photocatalytic activity of nitrides for hydrogen evolution.