Band gap of reduced graphene oxide tuned by controlling functional groups

Abstract

Functionalization of reduced graphene oxide with epoxide groups allows tuning its band gap energy.

Uncovering the origin of enhanced field emission properties of rGO–MnO2heterostructures: a synergistic experimental and computational investigation

“…This is consistent with experimental data that showed that the band gap of rGO can be tuned from 0.264-0.786 eV by controlling the surface concentration of epoxide groups. 67 The bulk a-MnO 2 was modelled tetragonal crystal structure (space group -I4/m, no. 87) in the antiferromagnetic AFM-C2 conguration 68 as shown in Fig.…”

Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO2 Gas Sensing Performance at Room Temperature

“…Some folds and wrinkles were also identified on edge of the surface. These corrugations on the AArGO25 surface can modify its electronic structure, mechanical, optical, and chemical properties [ 22 , 27 ].…”

“…The peak intensity of the AArGO25 carbonyl group (C=O) was found to be higher than that of GO, attributing to a higher number of carbonyl elements of the AArGO25 material. These carbonyl OFGs form the defective surface of AArGO25 [ 22 ]. These defects are the main active sites for the adsorption of the CO 2 gas molecules.…”

“…In addition, the gas sensors based on these materials have realized the longer recovery time (2–6 min). Besides these materials, graphene and its hybrids [ 15 , 19 , 20 , 21 ] are emerging as the promising contender for CO 2 detection at room temperature due to their extraordinary properties such as high surface to volume ratio, high conductivity, and high chemical reactivity [ 22 ]. Owing to its very high volume–exposure ratio, a small amount of the graphene-based material enriched with the high surface area can provide ample active sites for high adsorption of the analyte gas molecules [ 23 , 24 ].…”

Metal Organic Framework Derived MnO2-Carbon Nanotubes for Efficient Oxygen Reduction Reaction and Arsenic Removal from Contaminated Water

“…The C1s of GO plotted in bottom half of figure shows peaks centered at ~285.1 and 287.14 eV corresponding to carbonyl (C-O) and carboxyl (C=O) moieties of graphene oxide whereas the minor peak at 288.8 eV is attributed to carboxylic (O=C-O) groups [ 54 ]. However, in MnO 2 @CNT-rGO a broad peak centered at 284.5 eV corresponding to sp 2 carbon (C=C) is dominating with minor peaks at 286.4, 288.8 and 291.5 eV attributed to residual epoxides [ 55 ], carboxylic and plasmon resonance of valence electrons of rGO [ 56 ]. In order to study the ionic states of manganese moieties in Mn-H 3 BTC MOF and MnO 2 @CNT-rGO, high-resolution XPS spectroscopy was carried out and the deconvoluted Mn 2p of the two samples is plotted n Figure 2 c. In case of Mn-H 3 BTC MOF, two distinct peaks at 641.96 and 650.8 eV corresponding to Mn 2p 3/2 and Mn 2p 1/2 with a peak distance of 8.84 eV is observed whereas in MnO 2 @CNT-rGO the peaks are centered at 641.66 and 653.4 eV with a substantially higher peak distance of 11.74 eV.…”