Noble-metal-free MoS2 co-catalyst decorated UiO-66/CdS hybrids for efficient photocatalytic H2 production

A novel and highly efficient photocatalyst MoS2/UiO-66/CdS has been fabricated through dual modification of CdS with metal-organic framework (MOF) UiO-66 and MoS2. UiO-66 was firstly introduced as a matrix for the well-dispersed growth of CdS, resulting in large active surface area. Moreover, the heterojunction between UiO-66 and CdS promoted the separation of photogenerated electron-hole pairs. MoS2 as cocatalyst was further deposited on UiO-66/CdS via a facile photo-assisted approach. This technique made CdS, UiO-66 and MoS2 undergo an intimate interfacial interaction, setting a stage for rapid transfer of photogenerated electrons between the components of the composite, and hence dramatically increased the synergetic catalytic effect of UiO-66, MoS2 and CdS. Without a noble-metal cocatalyst, the obtained MoS2/UiO-66/CdS composites functioned as high-performance photocatalysts for H-2 evolution under irisible light irradiation. An unusual H-2 production rate of 650 mu mol h(-1) has been reached by the sample of MoS2/UiO-66/CdS when the content of UiO-66 is 50 wt% and MoS2 is 1.5 wt%. This is nearly 60 times higher than the H-2 evolution rate with pure CdS and also exceeds that of Pt/UiO-66/CdS under the same reaction conditions. More importantly, in sharp contrast with the obvious deterioration in photoactivity of pure CdS, the MoS2/UiO-66/CdS displayed significantly enhanced photostability. This study clearly demonstrates the benefit of using MOFs as ideal support and MoS2 as cocatalyst to work cooperatively for enhancing the photocatalytic H-2 evolution activity and stability of semiconductors. (C) 2014 Elsevier B.V. All rights reserved.