Metal-organic framework as nanoreactors to co-incorporate carbon nanodots and CdS quantum dots into the pores for improved H2 evolution without noble-metal cocatalyst

Avoiding the utilization of noble-metal cocatalyst and the aggregation of nano photocatalysts in the preparation and photocatalytic reaction are two important aspects in the area of photocatalytic H-2 evolution. In this work, for the first time, CdS quantum dots and carbon nanodots (CDs) were successfully co-immobilized in the cages of MIL-101 by one-step double solvents method followed by heating treatment. The optimum photocatalytic H-2 evolution rate of CD/CdS@MIL-101(50) composite with CDs content of 5.2 wt% exhibits a H-2 evolution rate of 14.66 mu mol h(-1) without noble metal assisted under visible-light irradiation, which is 8.5 and 18.6 times higher than that of CdS@MIL-101 and bare CdS, respectively. The improved photocatalytic H-2-production activity of CD/CdS@MIL-101 ternary composite is predominantly attributed to the effect of CDs, which mainly serves as an electron collector to efficiently prolong the lifetime of the photogenerated charge carriers from CdS@MIL-101 heterostructure. This work provide a new strategy of one-step double solvents method to co-incorporate two functional species to the pores of metal-organic frameworks (MOFs) to improve the photocatalytic H-2 evolution activity of host photocatalyst.