Synthesis of hybrid structures based on metal phthalocyanines/graphene oxide towards nonlinear optical applications

2,9,16,23-tetra-(6-mercaptohexylthio) phthalocyanine (MPc(THdT), M = Zn, In)-graphene oxide (MPc(THdT)-GO hybrids) and 2,9,16,23-tetra-(6-hydroxyhexyloxy) phthalocyanine (MPc(THdI), M = Zn, In)-graphene oxide (MPc(THdT)-GO hybrids) have been prepared with a covalent functionalization method. A series of characterizations revealed that phthalocyanine is covalently attachment on graphene oxide sheets. The third order nonlinear optical properties were investigated using the Z-scan technique at 532 nm with 4 ns laser pulses. The four kinds of MPc-GO hybrids exhibited much larger nonlinear optical absorption effects than that GO and Pc, respectively. Energy diagrams show that the PET process from Pc molecules to GO nanosheet exists. In the process of PET/ET, thioester bond between GO and MPc(THdT) make process of PET/ET easier, and the nonlinear absorption coefficient values of MPc(THdT)-GO hybrids are higher than those of MPc(THdI)-GO hybrids.