Modulation of Electrochemical Properties of Graphene Oxide by Photochemical Reduction Using UV-Light Emitting Diodes

Abstract

Electrodes that were chemically modified by reduced graphene oxide have properties that dependent on the synergy between the level of restoration of the sp2 structure and the functional groups. Because of this, the challenge in the chemistry of graphene is how to reach the equilibrium between electrical conductivity and specific interactions between the surface and molecular targets and how to tune it. In this work, a simple and effective method to modulate the electrochemical properties of reduced graphene oxide by photoreduction using UV‐light emitting diodes is reported. Moreover, we also succeeded in controlling the percentage of oxygenated groups and electrical conductivity, which reflects directly on the electrochemical behavior. The influence of the reduction extent is explored using photochemically reduced graphene oxide generated as a potential sensor for trace detection of dopamine, proving the efficiency and importance of this tunable reduction approach for device‐design development, mainly for the synergistic effect among electrical conductivity, π‐interaction and the amount of oxygenate functional groups.

Improvement in Efficiency of the Electrocatalytic Reduction of Hydrogen Peroxide by Prussian Blue Produced from the [Fe(CN)5(mpz)]2– Complex

“…Another important point in reversible processes is the value of Δ E , which is expected to be between 60–65 mV, but Δ E = 81 mV was obtained for PCF‐mpz. This increase in the separation of potential peaks represents a decrease in the heterogeneous electron‐transfer rate (HET), which can be assigned to the passivation of the electrode by non‐electroactive materials, and thus the HET decreases. This evidences a problem in the control of the surface composition when a glassy carbon electrode is freshly polished, for example .…”

Nanocomposite Materials Based on Electrochemically Synthesized Graphene Polymers: Molecular Architecture Strategies for Sensor Applications

“…As mentioned, the reduction of graphene sheets plays a significant role in the deposition mechanism. Additionally, the conductivity of graphene oxide has a direct relationship with the number of oxygen species present in its sheets, and this step can be strategically used to modulate or achieve certain desired characteristics in the material (Figure 6) [71][72][73][74]. In this sense, in electrochemical sensors, the common aim of the presence of graphene oxide is to guarantee good charge transfer in the system [25,75,76].…”

Assembly of Low-Cost Lab-Made Photoreactor for Preparation of Nanomaterials

“…Graphite oxide was synthesized using a modified Hummer's method 6 and graphene oxide (GO) was obtained by exfoliation of graphite oxide using an ultrasonic bath during 10 minutes. Photochemical reduction of graphene oxide was performed under UV-A and UV-C lamps in the lab-made photoreactor by irradiation of GO (1.0 mg mL -1 ) for 12 h and 24 h in quartz cuvettes.…”

“…On the other hand, the holes produced by light contribute to the oxidation of the C skeleton to CO 2 , but in minor proportion than the reduction. 6,14 The excitation with highly energetic light (UV-C) leads to the formation of a greatly reduced material and reduction level of GO can be controlled by setting the parameter such as time of irradiation, power of the lamp and wavelength.…”

“…5 Another example of the application of UV-light in materials is the modulation of the electrochemical properties of the graphene oxide through the control of reduction level which can be adjusted by the intensity and time of irradiation. 6 Thereby, it is possible to make a fine and planned adjustment in the final properties of the graphene oxide, which is sometimes difficult to control using chemical methods. An overview of the main uses of light to produce or modulate properties of (nano) materials is found in the Figure 1.…”