Photoreactivity of graphene oxide in aqueous system: Reactive oxygen species formation and bisphenol A degradation

Adeleye, Adeyemi S.; Wang, Xinzhe; Wang, Fanglu; Hao, Runlong; Song, Weihua; Li, Yao

doi:10.1016/j.chemosphere.2017.12.095

Cited by 39 publications

(31 citation statements)

References 38 publications

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“…Several studies have reported reduction in the particle size of GO when GO undergoes photoreduction reactions [48,49]. The photoreduction reactions significantly decrease the oxygen-containing functional groups (mostly epoxy and carbonyl groups) under UV irradiation, thereby producing defects in the basal planes of GO and forming holes and breakage of the nanosheets [48,49]. These studies are consistent with the observation in GO samples exposed to UV irradiation ( Figure 1C).…”

Section: Analysis Of Electrical Resistance Of Go-cnt Nanocomposite Thsupporting

confidence: 89%

“…This in turn, would decrease the electrostatic repulsions between the GO colloids and lead to an increase in aggregation of these colloids, increasing the particle size measurements over time. Several studies have reported reduction in the particle size of GO when GO undergoes photoreduction reactions [48,49]. The photoreduction reactions significantly decrease the oxygen-containing functional groups (mostly epoxy and carbonyl groups) under UV irradiation, thereby producing defects in the basal planes of GO and forming holes and breakage of the nanosheets [48,49].…”

Section: Analysis Of Electrical Resistance Of Go-cnt Nanocomposite Thmentioning

confidence: 99%

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Physicochemical Characteristics of Nanocomposites under Environmental Exposure Conditions for Space Applications

Hee¹,

S²,

M³

et al. 2019

Int J Nanoparticles Nanotech

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Despite well-perceived advancements of nanotechnology for space applications, application of nanotechnology in the aerospace industry has potential challenges in the perspectives of monitoring and accurately measuring types and levels of pollution. Nanomaterials applied for chemical nanosensors should be well characterized and designed to detect contaminant levels different from Earth's. However, a few studies have investigated the transformation and efficacy of aged nanomaterials in sensor development. The present study explored the aging effect of oxygenation, UV irradiation, and heat treatment on selected nanomaterials (i.e., GO, CNTs, ZnO nanowire, TiO 2 , and ZnO) in the perspective of sensing performance to detect trace contaminants. Further, GO-CNT nanocomposite thin films deposited on electrode chips were exposed to the CO 2 gas contaminant, and their electrical resistance was measured. Results indicate significant changes in physicochemical properties (particle size, zeta potential, and absorbance) of the model nanomaterials under oxygenation and UV irradiation, which was further investigated on their electric resistance upon exposure to gaseous contaminants. The assessment of changes to the CO 2-sensing ability of carbon-nanotube or graphene-oxide hybrid thin films suggests decreasing sensitivity under both UV irradiation and oxygenation.

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Section: Analysis Of Electrical Resistance Of Go-cnt Nanocomposite Thsupporting

confidence: 89%

Section: Analysis Of Electrical Resistance Of Go-cnt Nanocomposite Thmentioning

confidence: 99%

Physicochemical Characteristics of Nanocomposites under Environmental Exposure Conditions for Space Applications

Hee¹,

S²,

M³

et al. 2019

Int J Nanoparticles Nanotech

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“…Moreover, the I D /I G ratio increased with irradiation time (Table S4, Supporting Information), further confirming the gradual disordering of the carbon layer, as revealed by the XRD analysis. [72] The oxidation rates of the Ti 3 C 2 T x flakes under light irradiation observed in this study were much higher than those reported for the complete oxidation under darkness for over 15 d, [21,22,43] particularly under UV light. This suggests that dispersed MXene flakes may be vulnerable to photochemical degradation in the environment; thus, surface modification is warranted to improve their photochemical stability.…”

Section: Transformation Of Ti 3 C 2 T X Flakescontrasting

confidence: 61%

“…To detect O 2 − , both NBT 2+ and XTT were used. [72,82] NBT 2+ and XTT are two of the most widely used probes for detecting O 2 − as their reaction with O 2 − produces a product that absorbs light at 530 and 470 nm, respectively. But unlike NBT 2+ , XTT has the advantage that its reaction with O 2 − can be completely quenched and its reduction production was more soluble in water, making quantitative assessment less problematic.…”

Section: N I K T a Bmentioning

confidence: 99%

Dispersibility and Photochemical Stability of Delaminated MXene Flakes in Water

Shen

Tao

Rajavel

et al. 2020

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The environmental stability of 2D MXene flakes must be systematically studied before their further application. Herein, the colloidal dispersibility and photochemical stability of delaminated Ti3C2Tx MXene flakes modified with hydrazine (HMH) and KOH and with water as the control (HMH‐Ti3C2, KOH‐Ti3C2, and H2O‐Ti3C2, respectively) are experimentally and theoretically studied. Modification greatly increases the dispersibility of Ti3C2Tx flakes. Their critical coagulation concentrations are 28.7, 106, and 49.1 mm NaCl, and their Hamaker constants are 23.7 × 10−21, 19.1 × 10−21, and 37.7 × 10−21 J, respectively; the colloidal interaction follows the classical Derjaguin–Landau–Verwey–Overbeek theory. HMH‐Ti3C2 and KOH‐Ti3C2 exhibit higher photochemical stability, as indicated by their stronger resistance to oxidation under UV and visible light irradiation. Changes in their physicochemical properties and the generation of reactive oxygen species (ROS) are assayed. Spin‐polarized density functional theory calculations and molecular dynamics simulations are used to determine the mechanisms underlying the differences in the photochemical stability of Ti3C2Tx flakes. K+ ions protect the flakes from oxidation by acting as a middle layer to reduce the coupling between Ti3+ and ROS, while HMH provides stronger protection by absorbing photoelectrons or reacting with ROS. These findings provide new insight into the environmental transformation and design of functional MXenes.

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“…10 The reported value is uncertain, however, due to coexistence of direct photolysis and HO˙reaction. GO itself may generate 1 O 2 via photolysis 23,27,28 or by catalytic decomposition of H 2 O 2 , 29 a ubiquitous ROS species in natural waters. While 1 O 2 was reported to mediate the photooxidation of graphene, 30 reactivity of GO with 1 O 2 is not yet confirmed.…”

Section: Introductionmentioning

confidence: 99%

Reactivity of graphene oxide with reactive oxygen species (hydroxyl radical, singlet oxygen, and superoxide anion)

Hsieh

Zepp

2019

Environ. Sci.: Nano

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Photoreactivity of graphene oxide in aqueous system: Reactive oxygen species formation and bisphenol A degradation

Cited by 39 publications

References 38 publications

Physicochemical Characteristics of Nanocomposites under Environmental Exposure Conditions for Space Applications

Physicochemical Characteristics of Nanocomposites under Environmental Exposure Conditions for Space Applications

Dispersibility and Photochemical Stability of Delaminated MXene Flakes in Water

Reactivity of graphene oxide with reactive oxygen species (hydroxyl radical, singlet oxygen, and superoxide anion)

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