| 1. |
- Liu, Qing, et al.
(författare)
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Unraveling the unique role of brown graphitic carbon nitride in robust CO2 photoreduction
- 2023
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Ingår i: Applied Surface Science. - : ELSEVIER. - 0169-4332 .- 1873-5584. ; 615
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Tidskriftsartikel (refereegranskat)abstract
- Photocatalytic CO2 reduction is one of the important means to alleviate the energy crisis. In this work, an oxygen linked and brown graphitic carbon nitride (GACN) was successfully prepared by thermal polymerization after oil bath method. GACN introduced oxygen atoms on surface of BulkCN. Various characterizations of the material show that the prepared GACN has a different structure and higher photoelectronic activity compared to BulkCN. GACN possessed strong photocatalytic CO2 reduction capacity, and the photocatalytic activity was significantly improved compared with BulkCN. In view of density functional theory calculations, it is proved that the oxygen atoms introduced by GACN increase CO2 photoreaction reactivity, enhance electronic activity and reduce the reaction energy barrier. This work can have a positive effect on the photocatalytic application of g-C3N4 with the existence of oxygen atoms.
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| 2. |
- Zhu, Xingwang, et al.
(författare)
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Stacking Engineering of Heterojunctions in Half-Metallic Carbon Nitride for Efficient CO2 Photoreduction
- 2023
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Ingår i: Advanced Science. - : WILEY. - 2198-3844.
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Tidskriftsartikel (refereegranskat)abstract
- Enhancing charge separation in semiconductor photocatalysts is a major challenge for efficient artificial photosynthesis. Herein, a compact heterojunction is designed by embedding half-metallic C(CN)(3) (hm-CN) hydrothermally in BiOBr (BOB) as the backbone. The interface between hm-CN and BOB is seamless and formed by covalent bonding to facilitate the transmission of photoinduced electrons from BOB to hm-CN. The transient photocurrents and electrochemical impedance spectra reveal that the modified composite catalyst exhibits a larger electron transfer rate. The photocatalytic activity of hm-CN/BOB increases significantly as indicated by a CO yield that is about four times higher than that of individual components. Density-functional theory calculations verify that the heterojunction improves electron transport and decreases the reaction energy barrier, thus promoting the overall photocatalytic CO2 conversion efficiency. The half-metal nitride coupled semiconductor heterojunctions might have large potential in artificial photosynthesis and related applications.
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| 3. |
- Shen, Xiaozhi, et al.
(författare)
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Plasma diagnostic potential of 2p4f in N+ : accurate wavelengths and oscillator strengths
- 2015
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Ingår i: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 801:2
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Tidskriftsartikel (refereegranskat)abstract
- Radiative emission lines from nitrogen and its ions are often observed in nebula spectra, where the N2 + abundance can be inferred from lines of the 2p4f configuration. In addition, intensity ratios between lines of the 2p3p-2p3s and 2p4f-2p3d transition arrays can serve as temperature diagnostics. To aid abundance determinations and plasma diagnostics, wavelengths and oscillator strengths were calculated with high precision for electric dipole (E1) transitions from levels in the 2p4f configuration of N+. Electron correlation and relativistic effects, including the Breit interaction, were systematically taken into account within the framework of the multiconfiguration Dirac-Hartree-Fock method. Except for the 2p4f-2p4d transitions with quite large wavelengths and the two-electron-one-photon 2p4f-2s2p 3 transitions, the uncertainties of the present calculations were controlled to within 3% and 5% for wavelengths and oscillator strengths, respectively. We also compared our results with other theoretical and experimental values when available. Discrepancies were found between our calculations and previous calculations due to the neglect of relativistic effects in the latter.
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| 4. |
- Zhou, Xin, et al.
(författare)
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Simultaneous manipulation of scalable absorbance and the electronic bridge for efficient CO2 photoreduction
- 2022
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 10:48, s. 25661-25670
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Tidskriftsartikel (refereegranskat)abstract
- Highly active, low-cost, and stable photocatalysts are the key point for the development of photocatalysis technology, which is one of the most promising advanced approaches to a greener future. As a nonmetallic polymer with high performance, graphitic carbon nitride (g-C3N4) has a notable effect on photocatalytic CO2 reduction. However, the narrow light absorption limits its photocatalytic efficiency. In this work, we prepared red g-C3N4 with the oxygen bridge structure (CSCN) using a grinding thermal polymerization method. The oxygen bridge structure provides more active sites, broadens the light absorption range, and improves the charge separation efficiency. Benefiting from the combined above advantages, CSCN exhibited a rate of photocatalytic reduction of CO2 to CO of 28.5 mu mol g(-1) h(-1). This work proposes a way to enhance the light absorption efficiency and CO2 reduction properties of g-C3N4.
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