Novel structure and excellent nonlinear optical performance nanocomposite derived from flower-like MOF grown on MoS2

Molybdenum disulfide (MoS 2 ) is a nonlinear optical material with graphene-like structure. In order to further improve the nonlinear optical performance of MoS 2 and expand the application fields of MoS 2 , we report a simple in-situ self-growth method to functionalize MoS 2 nanosheets with metal-organic framework (MOF) for the first time to pursuit excellent reverse saturable absorption performance and optical limiting performance. Firstly, defective MoS 2 nanosheets was obtained by chemical etching with H 2 O 2 and cysteamine was inserted into the sulfur vacancies under ultrasound to obtain MoS 2 –NH 2 . Then 5,10,15,20-Tetra (4-carbomethoxyphenyl) porphyrin (TCPP) as MOF active growth sites were grafted on MoS 2 –NH 2 by amido linkage to obtain MoS 2 -TCPP in mild conditions. Finally, flower-like porphyrin-based CuMOF was grown on MoS 2 -TCPP by solvothermal method to obtain MoS 2 -CuMOF with stable structure. The third order nonlinear optical performance of MoS 2 -CuMOF were studied by Z-scan technique. It was found that the third order nonlinear absorption coefficient of MoS 2 -CuMOF was significantly improved compared with MoS 2 . Under the same energy of laser irradiation, the third order nonlinear absorption coefficient of MoS 2 -CuMOF nanocomposite in solution was 6 × 10 −10  m/W about 2.3 times of the pristine MoS 2 (2.6 × 10 −10  m/W). After blending the above materials with polymethyl methacrylate (PMMA) to prepare a solid device, the third order nonlinear absorption coefficient of MoS 2 -CuMOF/PMMA was 18 × 10 −10  m/W about 3.6 times of the MoS 2 /PMMA (5 × 10 −10  m/W). And MoS 2 -CuMOF/PMMA had better optical limiting ability than MoS 2 /PMMA. The significant improvement in the performance of the composites can be attributed to the energy transfer between MoS 2 and CuMOF, and porphyrin aggregation was inhibited by PMMA after the preparation of devices. Energy transfer can be proved by fluorescence spectroscopy. This work not only provided an example for the covalent functionalization of MoS 2 , but also offered a new method for designing materials with excellent nonlinear optical performance.