Controlling the charge transfer flow at the graphene/pyrene–nitrilotriacetic acid interface

Abstract

Tuning of the charge flow direction at the SAM–graphene interface by coordination of the SAM with a nickel cation.

Role of Metal Centers in Tuning the Electronic Properties of Graphene-Based Conductive Interfaces

“…The second important parameter to consider is the CT contribution ΔΦCT, which is substantial, and which has different sign for the different metal centers. As observed in our previous work, 23 the CT is not confined to the graphene/SAM interface ligated with various M 2+ cations (i.e. interaction between graphene and pyrene) but increases until the end of the molecular backbone (Figure 2).…”

“…The work function analysis has been carried considering the methodology reported in our previous study. 23 Briefly, the averaged electrostatic potential along the axis normal to the interface (i.e. z-axis) is used to directly estimate the work function shift, comparing the potential on the bare side and on the SAM-covered side of the surface.…”

“…in agreement with our previous study. 23 7B). On the other hand, the highest anodic photocurrent densities were recorded for the samples with Ni 2+ and imidazole (18.1 nA·cm -2 ), confirming that Ni 2+ cation promotes the charge transfer from SAM to graphene, as already observed in [23].…”

“…23 7B). On the other hand, the highest anodic photocurrent densities were recorded for the samples with Ni 2+ and imidazole (18.1 nA·cm -2 ), confirming that Ni 2+ cation promotes the charge transfer from SAM to graphene, as already observed in [23]. Nevertheless, the redox behaviour of the assemblies is more complex in the presence of Ni 2+ cation compared to the other metal centers investigated in this study, as this cation seems to promote generation of also cathodic currents at a negative bias of at least -200 mV (see Figure 7B).…”

Molecular mechanism of direct electron transfer in the robust cytochrome-functionalised graphene nanosystem

“…The FTO electrode was covered with SLG according to the procedure described previously. 20,25 The quality and the number of graphene layers on FTO was examined using Raman scattering spectroscopy (WITec Alpha300 Raman microscope). The morphological structure of the SLG monolayer on the FTO surface and cross-sectional imaging of the FTO/SLG/pyr-NTA-M 2+ electrodes was obtained by Field Emission Scanning Electron Microscope (FE-SEM, Zeiss Supra 55).…”