Hydrothermal synthesis of MoS2-NiS/CdS with enhanced photocatalytic hydrogen production activity and stability

Abstract

CdS is one of the most well-known photocatalysts for hydrogen production, while proper cocatalyst is indispensable to realize high hydrogen production performance. In this work, a three-component composite MoS2-NiS/CdS with dual cocatalysts was synthesized by a relatively facile and environmentally friendly three-step hydrothermal method and characterized by series of techniques. The as-prepared MoS2-NiS/CdS possesses good photostability and excellent photocatalytic hydrogen production performance. Under visible light irradiation of a 300 W Xe lamp (λ ≥ 420 nm), the H2 production rate reached a high value of 2525.2 μmol h−1 and the total amount of H2 evolved in 22 h achieved 40.5 mmol, further confirming that the photocatalysts with dual reduction cocatalysts possess higher photocatalytic performance than those with single cocatalyst. Especially, first study about the effect of pH of lactic acid aqueous solution on hydrogen production activity was carried out and the results indicated that increasing the pH from 1.5 to 3.0 leads to an obvious increase in H2-evolving activity. More importantly, an attempt on the photocatalytic hydrogen production under the irradiation of a 30 W LED lamp demonstrated that the H2 evolved was also up to 32.1 mmol in 48 h, showing the feasibility of using cheap and long lifetime LED lamp as light source for photocatalytic hydrogen production of CdS-based photocatalysts.