Near-UV light assisted green reduction of graphene oxide films through l-ascorbic acid

Abstract

Recent studies have highlighted the effects of various stimuli on the chemical reduction of graphene oxide (GO) through green reductant L-ascorbic acid (L-AA); however, the combination of near ultraviolet (NUV) light to increase the reduction rate has yet to be thoroughly explored. In this study, drop-casted GO films were subjected to chemical reduction through L-AA with various levels of exposure under 405 nm NUV radiation. The structure and uniformity of GO stackings that form the film were characterized through scanning electron microscopy (SEM) and wide-angle x-ray scattering (WAXS). Additionally, WAXS was used to track the removal of oxygencontaining functional groups along with Fourier-transform infrared (FT-IR) spectroscopy and x-ray photoelectron spectroscopy (XPS) as a function of L-AA and NUV light exposure times. XPS results demonstrated that the interaction between L-AA and NUV exposure has a significant effect on the reduction of films. Furthermore, the results that yielded the highest reduction (C-C bond concentration of 60.7%) were the longest L-AA and NUV light exposure times (48 hours and 3 hours, respectively). This report provides a study on the effects of NUV on the green reduction of GO films through L-AA with potential application in solar energy and chemical sensing applications.

Acoustotemplating: rapid synthesis of freestanding quasi-2D MOF/graphene oxide heterostructures for supercapacitor applications

“…, HKUST-1/GO) was achieved via a combination of ultraviolet (UV) light and chemical solution methods modified from the protocol in ref. 68. Briefly, a freestanding MOF/GO composite film formed by vacuum filtration (0.2 μm nylon membrane filter, Pall Corp., Port Washington, NY, USA) was immersed in a 20 mL solution of 4 mg mL −1 l -ascorbic acid ( l -AA) in H 2 O (99%, Sigma-Aldrich Pty.…”

“…and chemical solution methods modied from the protocol in ref. 68. Briey, a freestanding MOF/GO composite lm formed by vacuum ltration (0.2 mm nylon membrane lter, Pall Corp., Port Washington, NY, USA) was immersed in a 20 mL solution of 4 mg mL À1…”

Dynamics of reduced graphene oxide: synthesis and structural models

“…The mild heating is necessary for achieving appreciable reduction in a short time and despite this, the low temperature requirements still qualify the use of C 6 H 8 O 6 reductants as a green approach. Other reduction conditions in combination with ascorbic acid, such as stirring (rate and mode), high GO : reductant ratio, sonication, and alkaline pH, also shorten the reaction time from 48 to ∼1 h. 112 The use of biologically derived reductants is an interesting progress towards the sustainability of graphene-based materials, since both GO and RGO can also be biologically derived. [127][128][129] This is a step near the elimination of expensive, explosive, toxic and carcinogenic chemicals; 122,124 such as hydrazine (and its derivatives), 43,58 and sodium borohydride; 130 that harm the environment.…”

“…Despite these environmental limitations and also the introduction of impurities such as N moieties, hydrazine monohydrate (NH 2 NH 2 $H 2 O) is still commonly used as a reductant for aqua GO due to its high efficacy and weak reactivity with water unlike most chemical reductants (Table 3). 12,112 In general, most chemical reduction methodologies initially involve the dispersion of GO in water through ultrasonic treatment (Table 3). A common feature of the recent chemical reduction methodologies is the use of mild heating in the 80-100 °C range.…”

Graphene-Based Scaffolds: Fundamentals and Applications for Cardiovascular Tissue Engineering

“…After becoming aware of the criticality of these parameters, scientists can now devise rational bioengineering approaches to synthesize cell-friendly graphene materials and to fabricate biocompatible graphene-based biointerfaces. For example, green-chemistry synthesis methods are highly advisable ( Fernández-Merino et al, 2010 ; Khosroshahi et al, 2018 ; Regis et al, 2021 ), and graphene materials should be processed to eliminate various contaminants that might be cytotoxic on their own. Using large-surface graphene-integrated substrates could eliminate such problems as potential physical damage from sharp edges of graphene sheets.…”