Constructed CdS/Mn-MOF heterostructure for promoting photocatalytic degradation of Rhodamine B

A new 3D Mn-MOF was prepared with the ligand H2L (H2L = 5-(pyrazin-2-yl) isophthalic acid) by solvothermal method. Then the Mn-MOF was used as a precursor to synthesize CdS/Mn-MOF composites. The degradation efficiency of Rhodamine B (RhB) by CdS/Mn-MOF (theoretical mass ratio of CdS to Mn-MOF is 1:1) is 98.7% in 60 min, which is 19.7 times and 2.3 times that of Mn-MOF and CdS, respectively. The outstanding performance is owed to the loading of CdS, which significantly broadens the photoresponsive range of Mn-MOF and improves the utilization of visible light. Meanwhile, the heterojunction formed between Mn-MOF and CdS can effectively inhibit the recombination of photogenerated electrons and holes. Furthermore, the photocurrent intensity of CdS/Mn-MOF(50) is higher than that of Mn-MOF and CdS. The photocatalytic performance of CdS/Mn-MOF(50) also exhibits excellent stability and reusability. In addition, the enhanced mechanism of photocatalytic activity was investigated systematically.