Graphene oxide and graphitic carbon nitride nanocomposites assembled by electrostatic attraction forces: Synthesis and characterization

Svoboda, Ladislav; Škuta, Radim; Matějka, Vlastimil; Dvorský, Richard; Matýsek, Dalibor; Henych, Jiří; Mančík, Pavel; Praus, Petr

doi:10.1016/j.matchemphys.2019.02.077

Cited by 18 publications

(10 citation statements)

References 45 publications

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“…First, we analyzed the samples with standard gating using only negative and positive control. From Figure 4 a–e, it is clear that there was the interference of optical properties of QCDs [ 12 , 31 , 32 ] even though the viability of NM PCs was under 10%, which was correct for heat-killed cells ( Figure 4 e). Interaction of QCDs with cells resulted in the shift in the fluorescence intensity in the red detector (FL 2: ex.…”

Section: Resultsmentioning

confidence: 88%

“…Both QCDs and g-C 3 N 4 exhibited positive surface charge (+ 40 mV for QCDs and +24 mV g-C 3 N 4 ), but they had a completely different size and shape. While QCDs were very small sphere nanodots (5 nm) [ 12 ], the g-C 3 N 4 were loose agglomerates with irregular shapes with the Z-average of 880 nm (according to DLS) [ 31 , 32 ]. To have a greater awareness of the shape of NMs, we included our own TEM images, which are displayed in Figure 1 .…”

Section: Resultsmentioning

confidence: 99%

“…Having in mind a formation of agglomerates of g-C 3 N 4 and QCDs in culture media these CNMs are famous for their extraordinary fluorescence properties [ 12 , 32 ]. Logically, it was crucial to check if those agglomerates could interfere with the fluorescence probes (PI, Calcein) used in the LIVE/DEAD assay.…”

Section: Resultsmentioning

confidence: 99%

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Toxicity of Carbon Nanomaterials—Towards Reliable Viability Assessment via New Approach in Flow Cytometry

Malina

Poláková

Hirsch

et al. 2021

IJMS

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The scope of application of carbon nanomaterials in biomedical, environmental and industrial fields is recently substantially increasing. Since in vitro toxicity testing is the first essential step for any commercial usage, it is crucial to have a reliable method to analyze the potentially harmful effects of carbon nanomaterials. Even though researchers already reported the interference of carbon nanomaterials with common toxicity assays, there is still, unfortunately, a large number of studies that neglect this fact. In this study, we investigated interference of four bio-promising carbon nanomaterials (graphene acid (GA), cyanographene (GCN), graphitic carbon nitride (g-C3N4) and carbon dots (QCDs)) in commonly used LIVE/DEAD assay. When a standard procedure was applied, materials caused various types of interference. While positively charged g-C3N4 and QCDs induced false results through the creation of free agglomerates and intrinsic fluorescence properties, negatively charged GA and GCN led to false signals due to the complex quenching effect of the fluorescent dye of a LIVE/DEAD kit. Thus, we developed a new approach using a specific gating strategy based on additional controls that successfully overcame all types of interference and lead to reliable results in LIVE/DEAD assay. We suggest that the newly developed procedure should be a mandatory tool for all in vitro flow cytometry assays of any class of carbon nanomaterials.

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Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

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Toxicity of Carbon Nanomaterials—Towards Reliable Viability Assessment via New Approach in Flow Cytometry

Malina

Poláková

Hirsch

et al. 2021

IJMS

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“…Besides these positive and useful properties, the serious shortcoming of CN is fast recombination of photoinduced electrons and holes, which has been solved by the formation of heterojunction composites with metal oxides, inorganic salts noble metals, and so on [13][14][15][16]. Recently, we have investigated the heterojunction composites of CN with TiO 2 [17,18], WO 3 [19,20], SnO 2 [21], BiVO 4 [22,23], BiOIO 3 [24], ZnO [25], and graphene oxide [26]. Another possibility is the formation of heterojunction composites of pure and doped CN.…”

Section: Introductionmentioning

confidence: 99%

Post-Synthetic Derivatization of Graphitic Carbon Nitride with Methanesulfonyl Chloride: Synthesis, Characterization and Photocatalysis

et al. 2020

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Bulk graphitic carbon nitride (CN) was synthetized by heating of melamine at 550 °C, and the exfoliated CN (ExCN) was prepared by heating of CN at 500 °C. Sulfur-doped CN was synthesized by heating of thiourea (S-CN) and by a novel procedure based on the post-synthetic derivatization of CN with methanesulfonyl (CH3SO2−) chloride (Mes-CN and Mes-ExCN). The obtained nanomaterials were investigated by common characterization methods and their photocatalytic activity was tested by means of the decomposition of acetic orange 7 (AO7) under ultraviolet A (UVA) irradiation. The content of sulfur in the modified CN decreased in the sequence of Mes-ExCN > Mes-CN > S-CN. The absorption of light decreased in the opposite manner, but no influence on the band gap energies was observed. The methanesulfonyl (mesyl) groups connected to primary and secondary amine groups were confirmed by high resolution mass spectrometry (HRMS). The photocatalytic activity decreased in the sequence of Mes-ExCN > ExCN > CN ≈ Mes-CN > S-CN. The highest activity of Mes-ExCN and ExCN was explained by the highest amounts of adsorbed Acetic Orange 7 (AO7). In addition, in the case of Mes-ExCN, chloride ions incorporated in the CN lattice enhanced the photocatalytic activity as well.

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“…In recent years, g-C 3 N 4 was also successfully tested for the degradation of pharmaceuticals, such as sulfamethazine [36] or ciprofloxacin [37], which has become a worldwide issue. In particular, in our previous work, thermally exfoliated carbon nitride already showed very good photocatalytic efficiency in the degradation of dyes and phenol under visible light irradiation [38,39]. To enhance its photocatalytic activity, g-C 3 N 4 can also be combined with other photocatalytic materials such as TiO 2 , NiFeP, MnO 2 or Bi 12 TiO 20 to obtain synergic effect.…”

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confidence: 99%

Design and Performance of Novel Self-Cleaning g-C3N4/PMMA/PUR Membranes

et al. 2020

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In the majority of photocatalytic applications, the photocatalyst is dispersed as a suspension of nanoparticles. The suspension provides a higher surface for the photocatalytic reaction in respect to immobilized photocatalysts. However, this implies that recovery of the particles by filtration or centrifugation is needed to collect and regenerate the photocatalyst. This complicates the regeneration process and, at the same time, leads to material loss and potential toxicity. In this work, a new nanofibrous membrane, g-C 3 N 4 /PMMA/PUR, was prepared by the fixation of exfoliated g-C 3 N 4 to polyurethane nanofibers using thin layers of poly(methyl methacrylate) (PMMA). The optimal amount of PMMA was determined by measuring the adsorption and photocatalytic properties of g-C 3 N 4 /PMMA/PUR membranes (with a different PMMA content) in an aqueous solution of methylene blue. It was found that the prepared membranes were able to effectively adsorb and decompose methylene blue. On top of that, the membranes evinced a self-cleaning behavior, showing no coloration on their surfaces after contact with methylene blue, unlike in the case of unmodified fabric. After further treatment with H 2 O 2 , no decrease in photocatalytic activity was observed, indicating that the prepared membrane can also be easily regenerated. This study promises possibilities for the production of photocatalytic membranes and fabrics for both chemical and biological contaminant control.Polymers 2020, 12, 850 2 of 20 aqueous solutions [11][12][13][14]. Adsorption by activated carbon is the most used method of dye removal due to good removal efficiency of a wide variety of dyes. Performance is dependent on the type of carbon used and the characteristics of the wastewater. The removal rate can be improved using massive doses of activated carbon. However, the re-use of regenerated activated carbon results in a steep reduction in adsorption capacity and the efficiency of dye removal becomes unpredictable and dependent on massive doses of such re-used activated carbon. Activated carbon is also very expensive and its reactivation results in 10%-15% loss of the sorbent [15][16][17].A promising method in order to overcome issues such as limited sorption capacity and regeneration is the use of materials with photocatalytic activity. Carbon nitride (g-C 3 N 4 ) is a metal-free organic semiconductor. This material is an attractive candidate in the field of photocatalysis due to its chemical stability, non-toxicity, straightforward preparation procedure and ability to absorb light efficiently in the visible range due to a narrow band gap (2.7 eV) [18][19][20]. g-C 3 N 4 has been used in photocatalytic applications such as water splitting [21,22], the photocatalytic degradation of air pollutants, such as NOx [23,24], water pollutants such as the dyes, rhodamine B [25][26][27], methyl orange [28], and methylene blue [29][30][31], and other industrial pollutants such as antibiotics [32] or phenols [33][34][35]. In recent years, g-C 3 N 4 was also successfully tes...

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Graphene oxide and graphitic carbon nitride nanocomposites assembled by electrostatic attraction forces: Synthesis and characterization

Cited by 18 publications

References 45 publications

Toxicity of Carbon Nanomaterials—Towards Reliable Viability Assessment via New Approach in Flow Cytometry

Toxicity of Carbon Nanomaterials—Towards Reliable Viability Assessment via New Approach in Flow Cytometry

Post-Synthetic Derivatization of Graphitic Carbon Nitride with Methanesulfonyl Chloride: Synthesis, Characterization and Photocatalysis

Design and Performance of Novel Self-Cleaning g-C3N4/PMMA/PUR Membranes

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