Construction of MOF-based photocatalysts is promising work due to their considerable active sites and flexible structures. Herein, we present a facile double solvent and in-situ-growth strategy to integrate CdS NPs with MIL-101(Cr) to engineer CdS/MIL-101(Cr) composite photocatalyst. As-prepared CdS/ MIL-101(Cr) samples were characterized by TEM, SEM, BET, EPR, XPS, TPC and ESI. CdS/MIL-101(Cr) exhibited remarkable enhanced activity for conversion CO2 to CO under visible light irradiation, and the 36% CdS/MIL-101(Cr) showed the optimal performance in the all samples. The superior activity was attributed to following factors. The strong interaction between CdS and MIL-101(Cr) promoted the separation and transferring of the photogenerated charge carriers. A higher utilization efficiency of photoelectrons could be achieved with the MIL-101(Cr) possessing multiple absorptions and active sites for the photoreduction of CO2. Also, CdS/MIL-101(Cr) provided a special transferring path for photoelectrons, from CdS to MIL-101(Cr), then to photoreduction of CO2 , which could be certified by the calculation of energy-level and the survey of center dot O-2(-) of CdS and MIL-101(Cr). (C) 2019 Elsevier Inc. All rights reserved.