Construction of multi-interfacial charge transfer paths in the NiS/CdS@CuS composite for efficient and broadband visible light photocatalytic H2 production

Abstract

Broad-spectrum response and high charge separation are two important prerequisites and also challenges for a photocatalyst to achieve excellent activity. Herein, we developed a closely-contacted NiS/CdS@CuS hybrid photocatalyst to construct multi-interfacial charge transfer paths to address these two challenges. Different from previously reported, limited charge transfer for the CdS system, the synergy between photoinduced interfacial charge transfer (IFCT) at the intimate CdS/CuS interface and the superior H2 production cocatalyst (NiS) enables a multi-interfacial charge transfer, which greatly accelerates charge separation and achieves broadband H2 production. The optimal NiS/CdS@CuS composite exhibits the high H2 production activity of 25.02 mmol g−1 h−1 with an apparent quantum efficiency of 27.21% at 420 nm. This activity is even higher than that of the optimized Pt/CdS system. The creation of photoinduced IFCT allows the photocatalytic H2 production of CdS extended to 610 nm. Multiple comparison systems are constructed to understand the reaction mechanisms and highlight the importance of synergy between the three components. This work supplies a paradigm for fabricating efficient H2 production photocatalyst with both enhanced charge transfer dynamics and expanded light response range.