Resonance Raman spectroscopy characterization of linear carbon chains encapsulated by multi-walled carbon nanotubes

Moura, Thiago Alves de; Neves, W.Q.; Alencar, Rafael S.; Kim, Yoong Ahm; Endo, Morinobu; Vasconcelos, Thiago L.; Costa, Débora Vargas Ferreira; Candiotto, Graziâni; Capaz, Rodrigo B.; Araújo, Paulo T.; Filho, A. G. Souza; Paschoal, Alexandre Rocha

doi:10.1016/j.carbon.2023.118123

Cited by 11 publications

(4 citation statements)

References 36 publications

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“…With the increase of carbonization temperature, the absorption peak of C═C and the overtone absorption peak of aromatic benzene at 780-900 cm −1 were weakened, indicating that aromatic compounds in porous wood carbon underwent thermal polymerization and further formed amorphous carbon materials. [18] As shown in Raman spectra (Figure 2b), the D-peak at 1350 cm −1 represents the lattice defect of carbon atoms and the G-peak at 1590 cm −1 represents the in-plane stretching vibration of sp 2 C. [19] As the carbonization temperature increased, the relative intensity of the D-peak increased, indicating that the C chain was pyrolyzed and the lattice defect of the C atoms increased, which was further demonstrated in the XRD patterns at ≈26°(Figure 2c). The diffraction peaks at 2𝜃 = 15.57°and 34.56°were respectively attributed to the (002) and (211) planes of ZnCl 2 , indicating that ZnCl 2 was attached to carbonized wood in samples CW450 and CW550.…”

Section: Resultsmentioning

confidence: 99%

A Hybrid Photocatalytic System Splits Atmospheric Water to Produce Hydrogen

He,

Zeng,

Chen

et al. 2024

Adv Funct Materials

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Large‐scale photocatalytic water‐splitting panel reactor system is developed and demonstrated its commercial feasibility. However, water scarcity is one of the leading challenges for the sustainable development of photocatalytic hydrogen generation in a well‐lit area. Here, a water harvesting form air‐photothermal water evaporation‐photocatalytic hydrogen evolution (AWPH) system is devised. The hybrid system comprising carbonized wood (CWx) combined with the hygroscopic salt ZnCl2 and Pt‐modified g‐C3N4 nanosheets (Pt‐CN) as a photocatalyst is developed, in which the carbonized wood has a vertical pore structure that can provide attachment sites for the hygroscopic salt. The water adsorbed by ZnCl2 is driven along the vertical pore channels to the photocatalyst due to the photothermal conversion effect. The bi‐phase interfaces of vapor/photocatalyst/hydrogen produced by the photothermal‐photocatalytic system significantly reduce the interface barrier and substantially lower the resistance to hydrogen transport. CW550 exhibited a water uptake of 0.56 g g−1 and hydrogen yield of 21.99 µmol cm−2 under 100 mW cm−2 illumination at a flow rate of 2 mL min−1 for 5 h and a half at atmospheric pressure.

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Section: Resultsmentioning

confidence: 99%

A Hybrid Photocatalytic System Splits Atmospheric Water to Produce Hydrogen

He,

Zeng,

Chen

et al. 2024

Adv Funct Materials

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“…The Raman spectra of chain-type materials remain well documented. [33][34][35] Considering the relative intensity, the doublet at higher frequency was ascribed to the Cu 2 (CN) 6 cluster, where CN ligands with bifurcated coordination at their C end, and the remaining four ones participating in the CuÀ C=NÀ Cd coordination. Based on the relative intensity of the two bands in the doublet, the band at 2122 cm À 1 was ascribed to the two bifurcated CN ligands and the one at higher frequency (2132 cm À 1 ) to the linear chains,À N�CÀ CuÀ C�NÀ .…”

Section: Raman Spectramentioning

confidence: 99%

Atypical Metal‐Center Coordination in Two Cyanide‐Based Coordination Polymers

Vázquez,

Avila,

Mojica

et al. 2023

ChemistrySelect

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This contribution reports the crystal structure, solved and refined from single crystal XRD data, of two cyanide‐based coordination polymers, with K[Cu2(CN)3] ⋅ H2O (1) and [Cd(H2O)]2Cd(H2O)2[Cu(CN)3Cu(CN)2]2 ⋅ 8H2O (2) as formula units. These coordination polymers are characterized by metal‐metal bonds between copper atoms. In 1, the framework is formed by Cu−Cu(CN)3 pseudo tetrahedral blocks linked by planar Cu2(CN)3 units. In this material, a defined Cu−Cu bond was identified, which is congruent with the corresponding Raman spectrum. The K atom and water molecule occupy the framework cavities. In 2, the Cu−Cu bond is observed in Cu2(CN)6 blocks which remain linked to Cd(NC)2(H2O)4 and Cd(NC)4(H2O)2 units occupying their axial and equatorial coordination positions, respectively. The solid framework is completed by the −N=C−Cu−C=N− chains linked to Cd(NC)4(H2O)2 moieties. The crystal structure for 2 contains two different sites for the metal centers. The structural study was complemented by recording IR, Raman, and UV/Vis spectra. These two coordination polymers behave as semiconductor materials with a band gap of 2.79 and 3.43 eV, respectively, as derived from the Tauc plot of the corresponding UV/Vis spectrum. Band structure calculations properly supported these values. 1 is a material of an indirect band gap, while 2 has a direct band gap.

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“… , The successful introduction of CNTs can also be evidenced by the existence of the D-band and G-band, and two peaks at 2183 and 2200 cm –1 suggest the presence of Co–CN–Co (Figure S8). , …”

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confidence: 99%

“…23,34 The successful introduction of CNTs can also be evidenced by the existence of the D-band and G-band, and two peaks at 2183 and 2200 cm −1 suggest the presence of Co−C�N−Co (Figure S8). 35,36 Nitrogen adsorption−desorption isotherms are used to assess the surface area and porosity properties of CNTs/ CoHCC nanoboxes. As shown in Figure 1j, the Brunauer− Emmett−Teller surface area of the CNTs/CoHCC nanoboxes is 448.9 m 2 g −1 , which is significantly larger than that of CoHCC nanocubes (65.3 m 2 g −1 ).…”

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confidence: 99%

Ultrathin Cobalt-Based Prussian Blue Analogue Nanosheet-Assembled Nanoboxes Interpenetrated with Carbon Nanotubes as a Fast Electron/Potassium-Ion Conductor for Superior Potassium Storage

Xu,

Yuan,

Song

et al. 2023

Nano Lett.

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Rechargeable potassium-ion batteries (PIBs) are regarded as potential substitutes for industrial lithium-ion batteries in large scale energy storage systems due to the world’s abundant potassium supplies. Althogh cobalt hexacyanocobaltate (CoHCC) exhibits broad potential as a PIB anode material, its performance is currently unsatisfactory. Herein, novel 5 nm scale ultrathin CoHCC nanosheet-assembled nanoboxes with interspersed carbon nanotubes (CNTs/CoHCC nanoboxes) are fabricated to realize a highly reactive PIB anode. The ultrathin CoHCC layers substantially accelerate electron conduction and provide numerous active sites, while the connected CNTs provide fast axial electron transport. Consequently, the optimized anode exhibits a remarkable discharge capacity of 580.9 mAh g–1 at 0.1 A g–1 and long-term stability with 71.3% retention over 1000 cycles. In situ and ex situ characterizations and density functional theory calculations are further employed to elucidate the K+ storage process and the reason for the enhanced performance of the CNTs/CoHCC nanoboxes.

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Resonance Raman spectroscopy characterization of linear carbon chains encapsulated by multi-walled carbon nanotubes

Cited by 11 publications

References 36 publications

A Hybrid Photocatalytic System Splits Atmospheric Water to Produce Hydrogen

A Hybrid Photocatalytic System Splits Atmospheric Water to Produce Hydrogen

Atypical Metal‐Center Coordination in Two Cyanide‐Based Coordination Polymers

Ultrathin Cobalt-Based Prussian Blue Analogue Nanosheet-Assembled Nanoboxes Interpenetrated with Carbon Nanotubes as a Fast Electron/Potassium-Ion Conductor for Superior Potassium Storage

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