Sustainable Recovery of CO2 by Using Visible-Light-Responsive Crystal Cuprous Oxide/Reduced Graphene Oxide

A simple solution-chemistry method has been investigated to prepare crystal cuprous oxide (Cu2O) incorporated with reduced graphene oxide (designated as Cu2O-rGO-x, where x represents the contents of rGO = 1%, 5% and 10%) in this work. These Cu2O-rGO-x composites combine the prospective advantages of rhombic dodecahedra Cu2O together with rGO nanosheets which have been studied as visible-light-sensitive catalysts for the photocatalytic production of methanol from CO2. Among the Cu2O-rGO-x photocatalysts, the methanol yield photocatalyzed by Cu2O-rGO-5% can be observed to be 355.26 μmol g−1cat, which is ca. 36 times higher than that of pristine Cu2O nanocrystal in the 20th hour under visible light irradiation. The improved activity may be attributed to the enhanced absorption ability of visible light, the superior separation of electron–hole pairs, well-dispersed Cu2O nanocrystals and the increased photostability of Cu2O, which are evidenced by employing UV-vis diffuse reflection spectroscopy, photoluminescence, scanning electron microscopy/transmission electron microscopy and X-ray photoelectron spectroscopy, respectively. This work demonstrates an easy and cost-effective route to prepare non-noble photocatalysts for efficient CO2 recovery in artificial photosynthesis.

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Reduced graphene oxide supported C3N4 nanoflakes and quantum dots as metal-free catalysts for visible light assisted CO2 reduction

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.10.44 ◽

2019 ◽

Vol 10 ◽

pp. 448-458 ◽

Cited By ~ 5

Author(s):

Md Rakibuddin ◽

Haekyoung Kim

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Visible Light ◽

Reduced Graphene Oxide ◽

Hybrid Materials ◽

Photoelectron Spectroscopy ◽

X Ray ◽

Metal Free ◽

Reduced Graphene ◽

Vis Spectroscopy

The visible light photocatalytic reduction of CO2 to fuel is crucial for the sustainable development of energy resources. In our present work, we report the synthesis of novel reduced graphene oxide (rGO)-supported C3N4 nanoflake (NF) and quantum dot (QD) hybrid materials (GCN) for visible light induced reduction of CO2. The C3N4 NFs and QDs are prepared by acid treatment of C3N4 nanosheets followed by ultrasonication and hydrothermal heating at 130–190 °C for 5−20 h. It is observed that hydrothermal exposure of acid-treated graphitic carbon nitride (g-C3N4) nanosheets at low temperature generated larger NFs, whereas QDs are formed at higher temperatures. The formation of GCN hybrid materials was confirmed by powder X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy (TEM), and UV–vis spectroscopy. High-resolution TEM images clearly show that C3N4 QDs (average diameter of 2–3 nm) and NFs (≈20–45 nm) are distributed on the rGO surface within the GCN hybrid material. Among the as-prepared GCN hybrid materials, GCN-5 QDs exhibit excellent CO2 reductive activity for the generation of formaldehyde, HCHO (10.3 mmol h−1 g−1). Therefore, utilization of metal-free carbon-based GCN hybrid materials could be very promising for CO2 photoreduction because of their excellent activity and environmental sustainability.

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Reduced Graphene Oxide Supported Molybdenum Oxide Hybrid Nanocomposites: High Performance Electrode Material for Supercapacitor and Photocatalytic Applications

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.17779 ◽

2020 ◽

Vol 20 (7) ◽

pp. 4035-4046

Author(s):

Rengasamy Dhanabal ◽

Dhanasekaran Naveena ◽

Sivan Velmathi ◽

Arumugam Chandra Bose

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Hybrid Nanocomposites ◽

X Ray ◽

Supercapacitor Application ◽

Quenching Effect ◽

Reduced Graphene

Using a simple solution based synthesis route, hexagonal MoO3 (h-MoO3) nanorods on reduced graphene oxide (RGO) sheets were prepared. The structure and morphology of resulting RGO-MoO3 nanocomposite were characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). The optical property was studied using UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS) and photoluminescence spectroscopy (PL). The RGO-MoO3 nanocomposites were used as an electrode for supercapacitor application and photocatalyst for photodegradation of methylene blue (MB) and rhodamine B (RhB) under visible light irradiation. We demonstrated that the RGO-MoO3 electrode is capable of delivering high specific capacitance of 134 F/g at current density of 1 A/g with outstanding cyclic stability for 2000 cycles. The RGOMoO3 photocatalyst degrades 95% of MB dye within 90 min, and a considerable recyclability up to 4 cycles was observed. The quenching effect of scavengers test confirms holes are main reactive species in the photocatalytic degradation of MB. Further, the charge transfer process between RGO and MoO3 was schematically demonstrated.

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Reduced Graphene Oxide–Epoxy Grafted Poly(Styrene-Co-Acrylate) Composites for Corrosion Protection of Mild Steel

Coatings ◽

10.3390/coatings9100666 ◽

2019 ◽

Vol 9 (10) ◽

pp. 666

Author(s):

Xinchuan Fan ◽

Yue Hu ◽

Yijun Zhang ◽

Jiachen Lu ◽

Xiaofeng Chen ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Photoelectron Spectroscopy ◽

X Ray Diffraction ◽

Corrosion Properties ◽

X Ray ◽

Transmission Electron ◽

Reduced Graphene ◽

Scanning Electron

Reduced graphene oxide–epoxy grafted poly(styrene-co-acrylate) composites (GESA) were prepared by anchoring different amount of epoxy modified poly(styrene-co-acrylate) (EPSA) onto reduced graphene oxide (rGO) sheets through π–π electrostatic attraction. The GESA composites were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion properties of rGO/EPSA composites were evaluated by electro-chemical impedance spectroscopy (EIS) in hydroxyl-polyacrylate coating, and the results revealed that the corrosion rate was decreased from 3.509 × 10−1 to 1.394 × 10−6 mm/a.

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Facile Synthesis of Modified MnO2/Reduced Graphene Oxide Nanocomposites and their Application in Supercapacitors

NANO ◽

10.1142/s179329202050099x ◽

2020 ◽

Vol 15 (08) ◽

pp. 2050099

Author(s):

Lijun Chen ◽

Hongfeng Yin ◽

Yuchao Zhang ◽

Huidong Xie

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Specific Capacitance ◽

Reduced Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Electrode Materials ◽

Normal Pressure ◽

X Ray ◽

Assembly Method ◽

Reduced Graphene

Herein, KH-550 was used as surface modifier to prepare modified MnO2/reduced graphene oxide (M-MnO2/rGO) composite electrode materials by utilizing electrostatic interaction at low temperature and normal pressure. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were adopted to characterize the material’s phase, morphology, and valence state of elements. The electrochemical properties of the material were measured using a three-electrode system. The results indicate a decrease in the size of the modified MnO2 particles, and that they were uniformly distributed on the rGO sheets. The M-MnO2/rGO composite attained a specific capacitance of 326[Formula: see text]F[Formula: see text]g[Formula: see text] in a solution of 1[Formula: see text]mol[Formula: see text]L[Formula: see text] Na2SO4 at a current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text]. The specific capacitance of the material was 92.4% after 1000 cycles. The electrostatic self-assembly method effectively solved the problem of reducing the cycling stability while improving the specific capacitance of the composite materials, and further improved the possibility of applying MnO2/rGO in the field of supercapacitors.

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Incorporation of reduced graphene oxide into faceted flower-like {001} TiO 2 for enhanced photocatalytic activity

Royal Society Open Science ◽

10.1098/rsos.180613 ◽

2018 ◽

Vol 5 (8) ◽

pp. 180613 ◽

Cited By ~ 3

Author(s):

Haijin Liu ◽

Peiyao Li ◽

Haokun Bai ◽

Cuiwei Du ◽

Dandan Wei ◽

...

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Graphene Oxide ◽

Visible Light ◽

Reduced Graphene Oxide ◽

Theoretical Calculations ◽

X Ray ◽

Transmission Electron ◽

Reduced Graphene ◽

Photocatalytic Activities

Anatase TiO 2 with {001} facets is much more active than that with {101} facets, which has been verified via experiments and theoretical calculations. Graphene has garnered much attention since it was initially synthesized, due to its unique properties. In this study, reduced graphene oxide (RGO)/{001} faceted TiO 2 composites were fabricated via a solvothermal method. The composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectrophotometry, photoluminescence and Raman analysis. The results revealed that the graphene oxide was reduced during the preparation process of the {001} faceted TiO 2 , and combined with the surface of {001} TiO 2 . The photocatalytic activities of the composites were evaluated through the degradation of basic violet, under both white light ( λ > 390 nm) and visible light ( λ = 420 nm) irradiation. The results indicated that the photocatalytic activities of the {001} faceted TiO 2 were significantly improved following the incorporation of RGO, particularly under visible light irradiation. Theoretical calculations showed that the band structure of the {001} faceted TiO 2 was modified via graphene hybridization, where the separation of photoinduced electron–hole pairs was promoted; thus, the photocatalytic activity was enhanced.

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A highly photoactive, visible-light-driven graphene/2D mesoporous TiO2 photocatalyst

Green Chemistry ◽

10.1039/c5gc00641d ◽

2015 ◽

Vol 17 (7) ◽

pp. 3972-3978 ◽

Cited By ~ 65

Author(s):

Kyeong Min Cho ◽

Kyoung Hwan Kim ◽

Hyung Ouk Choi ◽

Hee-Tae Jung

Keyword(s):

Graphene Oxide ◽

Visible Light ◽

Reduced Graphene Oxide ◽

Surface Area ◽

Charge Separation ◽

Mesoporous Tio2 ◽

Tio2 Photocatalyst ◽

Enhanced Absorption ◽

Reduced Graphene ◽

Visible Light Driven

In this paper, we have reported a new, visible-light-driven photocatalyst composed of 2D mesoporous TiO2 on reduced graphene oxide, which enables enhanced absorption of visible light, showing outstanding charge separation ability, and a large surface area.

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Ce2O3/BiVO4 Embedded in rGO as Photocatalyst for the Degradation of Methyl Orange under Visible Light Irradiation

J ◽

10.3390/j4020013 ◽

2021 ◽

Vol 4 (2) ◽

pp. 154-168

Author(s):

Damian C. Onwudiwe ◽

Boitumelo M. Phadi ◽

Opeyemi A. Oyewo

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Graphene Oxide ◽

Methyl Orange ◽

Visible Light ◽

Reduced Graphene Oxide ◽

Visible Light Irradiation ◽

Light Irradiation ◽

Reduced Graphene ◽

Degradation Of Methyl Orange

A p–n heterojunction semiconductor structure composed of Ce3O4 and BiVO4 has been synthesized and then incorporated into reduced graphene oxide (rGO) by the hydrothermal method. The ternary composites were characterized by X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), and UV–vis spectroscopy. The efficiency of the composites as photocatalysts was determined by studying the oxidative degradation of methyl orange in aqueous solution under visible light irradiation. The effect of parameters such as pH, catalyst loading, and concentration of the dye solution was examined in order to determine their influence on the photocatalytic activity of the composites. The composite incorporated into reduced graphene oxide presented the highest percentage (above 90%) in 2 h time, attributed to the effect of the increased surface area. The process of the enhanced photocatalytic activity has been discussed based on the energy band positions of the nanoparticles within the composite.

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Reduced Graphene Oxide/TiO2 Nanocomposite: From Synthesis to Characterization for Efficient Visible Light Photocatalytic Applications

Catalysts ◽

10.3390/catal8120598 ◽

2018 ◽

Vol 8 (12) ◽

pp. 598 ◽

Cited By ~ 19

Author(s):

Elena Rommozzi ◽

Marco Zannotti ◽

Rita Giovannetti ◽

Chiara D’Amato ◽

Stefano Ferraro ◽

...

Keyword(s):

Graphene Oxide ◽

Visible Light ◽

Reduced Graphene Oxide ◽

Photoelectron Spectroscopy ◽

Thermal Reduction ◽

Alizarin Red S ◽

Alizarin Red ◽

Force Microscopy ◽

Reduced Graphene ◽

Visible Light Photocatalytic

In this study, a green and facile thermal reduction of graphene oxide using an eco-friendly system of d-(+)-glucose and NH4OH for the preparation of reduced graphene oxide was described. The obtained reduced graphene oxide dispersion was characterized by SEM, Dynamic Light Scattering, Raman and X-Ray Photoelectron Spectroscopy. TiO2 nanoparticles and reduced graphene oxide nanocomposites were successively prepared and used in the preparation of heterogeneous photocatalysts that were characterized by Atomic Force Microscopy and Photoluminescence Spectroscopy and subsequently tested as visible light photocatalysts for the photodegradation of Alizarin Red S in water as target pollutant. Obtained results of photocatalytic tests regarding the visible light photocatalytic degradation of Alizarin Red S demonstrated that the use of reduced graphene oxide in combination with TiO2 led to a significant improvement for both adsorption of Alizarin Red S on the catalyst surface and photodegradation efficiencies when compared to those obtained with not doped TiO2.

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Enhanced photocatalytic performance of Nb doped TiO2/reduced graphene oxide nanocomposites over rhodamine B dye under visible light illumination

Sustainable Environment Research ◽

10.1186/s42834-021-00110-x ◽

2021 ◽

Vol 31 (1) ◽

Author(s):

Neradabilli Prabhakarrao ◽

Tirukkovalluri Siva Rao ◽

Kapuganti Venkata Divya Lakshmi ◽

Gorli Divya ◽

Genji Jaishree ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Visible Light ◽

Reduced Graphene Oxide ◽

Rhodamine B ◽

Photocatalytic Performance ◽

Diffuse Reflectance Spectroscopy ◽

Light Exposure ◽

Light Illumination ◽

Reduced Graphene

AbstractThe present study discusses the synthesis of Nb doped TiO2/reduced graphene oxide (rGO) intercalated nanocomposites via sol-gel route at a lower temperature by using different loading amounts of graphene oxide (GO) (1 to 10 wt%). The synthesized composite materials were further characterized by copious instruments such as X-ray Diffractometer, UV-Vis Diffuse Reflectance Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, Brunauer-Emmett-Teller surface area analysis, Raman and Fourier Transform-Infrared Spectroscopy. The experimental results stated that the Nb doped TiO2 nanoparticles uniformly distributed on the surface of rGO with an interfacial linking bond between TiO2 and rGO. Later, the photocatalytic degradation of Rhodamine B (RhB) dye using produced materials under visible light irradiation was examined. These results revealed that Nb doped TiO2/rGO nanocomposites exhibited better photocatalytic performance than Nb doped TiO2 for the removal of RhB dye. However, among all, the nanocomposite having 5 wt% of GO content achieves the highest degradation efficiency for RhB dye approximately 98% under visible light exposure. Altogether, the unique properties such as electron accepting and transporting properties of GO in the nanocomposite is caused to enhance photocatalytic activity by minimizing the charge carrier’s recombination rate.

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Synthesis of MgFe2O4/Reduced Graphene Oxide Composite and Its Visible-Light Photocatalytic Performance for Organic Pollution

International Journal of Photoenergy ◽

10.1155/2018/7082785 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Fengmin Wu ◽

Wenlu Duan ◽

Mei Li ◽

Hang Xu

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Visible Light ◽

Reduced Graphene Oxide ◽

Photocatalytic Performance ◽

Light Response ◽

Organic Pollution ◽

Reduced Graphene ◽

Potential Applications ◽

Electron Hole Pair

Recently, binary metal oxides have been proven to be the most investigated semiconductors due to their high activity for the removal of organic pollutants. In this paper, to improve the photocatalytic efficiency of MgFe2O4, a MgFe2O4/reduced graphene oxide (MFO/rGO) photocatalyst was synthesized by a facile generalized solvothermal method. The morphology, structure, and photocatalytic activities in the degradation of methyl orange (MO) reaction were systematically characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and UV-vis absorption spectroscopy, respectively. The results showed that the MFO/rGO composite exhibited enhanced photocatalytic performance in the photodegradation of MO under visible-light irradiation and reached a maximum degradation rate of 99% within 60 min of irradiation. This excellent photocatalytic performance is attributed to the introduction of rGO in the composite, which can effectively reduce the photoproduction of the electron-hole pair recombination rate. The excellent photocatalytic activity reveals that the MFO/rGO composite photocatalyst is a promising photocatalyst with good visible-light response and has potential applications in the field of water treatment.

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