A reduced graphene oxide with regulatable sp² hybrid carbon configuration/cluster structure presents significant nonlinear optical properties.

Tetracarboxylic Zn(II) phthalocyanine–amino functionalized graphene oxide (ZnPcC₄–NGO) hybrid materials have been prepared by a covalent functionalization method. The characterizations indicate that the amino-functionalization of GO has an important influence on the structure and photophysical properties of the ZnPcC₄–NGO hybrid. The ZnPcC₄–NGO hybrid exhibits enhanced photo-induced electron transfer or energy transfer (PET/ET), compared to the ZnPcC₄ covalent functionalized GO (ZnPcC₄–GO), owing to the presence of the extended sp² carbon configurations, along with the partial reduction of the NGO nanosheets and the introduction of electron-donating ethylenediamine. The nonlinear optical (NLO) properties of the hybrids were investigated using the Z-scan technique at 532 nm with 4 ns laser pulses. The results show that the efficient covalent functionalization and partial reduction of NGO cause the ZnPcC₄–NGO hybrid to possess evidently larger NLO properties than the individual NGO, ZnPcC₄ and the ZnPcC₄–GO hybrid. The enhanced NLO performance can be attributed to the increased excited state absorption from the extended sp² carbon configurations of the NGO moiety, reverse saturable absorption arising from ZnPcC₄ moiety, and the contribution of the efficient PET/ET process between the ZnPcC₄ and NGO moieties in the hybrid.

An investigation of the effects of central metals on the photophysical and nonlinear optical performance of RGO–MPc hybrids.

Both kinds of GO–ZnPc hybrid materials exhibit transformation of the NLO response from SA to RSA, and the β value of GO–ZnPc(DG) ₄ is larger than that of GO–ZnPc(TD) ₄ because of the stronger electron-donating peripheral substituents.

An ethylenediamine (EDA) gas sensor based on a composite of MoO₃ nanoribbon and reduced graphene oxide (rGO) was fabricated in this work. MoO₃ nanoribbon/rGO composites were synthesized using a hydrothermal process. The crystal structure, morphology, and elemental composition of MoO₃/rGO were analyzed via XRD, FT-IR, Raman, TEM, SEM, XPS, and EPR characterization. The response value of MoO₃/rGO to 100 ppm ethylenediamine was 843.7 at room temperature, 1.9 times higher than that of MoO₃ nanoribbons. The MoO₃/rGO sensor has a low detection limit (LOD) of 0.235 ppm, short response time (8 s), good selectivity, and long-term stability. The improved gas-sensitive performance of MoO₃/rGO composites is mainly due to the excellent electron transport properties of graphene, the generation of heterojunctions, the higher content of oxygen vacancies, and the large specific surface area in the composites. This study presents a new approach to efficiently and selectively detect ethylenediamine vapor with low power.