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Self-hybridized coralloid graphitic carbon nitride deriving from deep eutectic solvent as effective visible light photocatalysts
摘要： The room temperature deep eutectic solvent (DES) is demonstrated as an ideal precursor to prepare self-hybridized graphitic carbon nitride (g-C3N4) for the first time, for its special components, randomly reorganized molecules and extensive hydrogen bonds. In this work, by adjusting the proportion of urea and ammonium thiocyanate in the precursor DES, the self-hybridized coralloid g-C3N4, stacked by a mass of double-layer g-C3N4/g-C3N4 nanocages, were prepared without any templates. Compared to conventional g-C3N4 prepared using melamine, urea and AT as precursors, the improved charge transfer between the interfaces of the self-hybridized g-C3N4 has been demonstrated, which is attributed to the well-matched electronic band structures of the two g-C3N4 species, the abundant 2D/2D interfacial contact and increased photocatalytic active sites. As expected, it exhibits highly enhanced photocatalytic activity, which is among the best g-C3N4 photocatalysts without doping any other elements.
关键词： G-C3N4/g-C3N4 heterojunction,Graphitic carbon nitride,Photocatalysis,Nanocages,Deep eutectic solvents
更新于2025-09-23 15:23:52
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Sub-5 nm Ultra-Fine FeP Nanodots as Efficient Co-Catalysts Modified Porous g-C <sub/>3</sub> N <sub/>4</sub> for Precious-Metal-Free Photocatalytic Hydrogen Evolution under Visible Light
摘要： Sub-5 nm ultra-fine iron phosphide (FeP) nano-dots-modified porous graphitic carbon nitride (g-C3N4) heterojunction nanostructures are successfully prepared through the gas-phase phosphorization of Fe3O4/g-C3N4 nanocomposites. The incorporation of zero-dimensional (0D) ultra-small FeP nanodots co-catalysts not only effectively facilitate charge separation but also serve as reaction active sites for hydrogen (H2) evolution. Herein, the strongly coupled FeP/g-C3N4 hybrid systems are employed as precious-metal-free photocatalysts for H2 production under visible-light irradiation. The optimized FeP/g-C3N4 sample displays a maximum H2 evolution rate of 177.9 μmol h?1 g?1 with the apparent quantum yield of 1.57% at 420 nm. Furthermore, the mechanism of photocatalytic H2 evolution using 0D/2D FeP/g-C3N4 heterojunction interfaces is systematically corroborated by steady-state photoluminescence (PL), time-resolved PL spectroscopy, and photoelectrochemical results. Additionally, an increased donor density in FeP/g-C3N4 is evidenced from the Mott-Schottky analysis in comparison with that of parent g-C3N4, signifying the enhancement of electrical conductivity and charge transport owing to the emerging role of FeP. The density functional theory calculations reveal that the FeP/g-C3N4 hybrids could act as a promising catalyst for the H2 evolution reaction. Overall, this work not only paves a new path in the engineering of monodispersed FeP-decorated g-C3N4 0D/2D robust nanoarchitectures but also elucidates potential insights for the utilization of noble-metal-free FeP nanodots as remarkable co-catalysts for superior photocatalytic H2 evolution.
关键词： transition-metal phosphides,g-C3N4,co-catalysts,precious-metal-free,photocatalytic H2 production
更新于2025-09-23 15:23:52
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A high-performance photoelectrochemical water oxidation system with phosphorus doping g-C3N4 and simultaneous metal phosphide cocatalyst formation via a gas treatment
摘要： Graphitic carbon nitride (g-C3N4) has been widely explored as photocatalyst for water splitting. The anodic water oxidation reaction (WOR) remains the major obstacle for such process, with particular issues on low surface area of g-C3N4, poor light absorption as well as low charge transfer efficiency. In this work, such longtime concerned issues have been partially addressed with band gap and surface engineering of nanostructured graphitic C3N4. Specifically, surface area and charge transfer efficiency are significantly enhanced via architecturing g-C3N4 on nanorod TiO2 to avoid the aggregation of layered g-C3N4. Moreover, a simple phosphide gas treatment of TiO2/g-C3N4 configuration not only narrows the band gap of g-C3N4 by 0.57 eV into visible range, but also in-situ generates a metal phosphide (M=Fe, Cu) water oxidation cocatalyst. This TiO2/g-C3N4/FeP configuration significantly improves charge separation and transfer capability. As a result, our photoelectrochemical system yields outstanding visible light (> 420 nm) photocurrent: ca. 0.3 mA·cm-2 at 1.23 V and 1.1 mA·cm-2 at 2.0 V vs RHE, the highest using g-C3N4 as photoanode. We expect that our TiO2/g-C3N4/FeP configuration generating via simple phosphide gas treatment will bring in new insight for robust g-C3N4 for water oxidation.
关键词： doping,photoelectrochemical,cocatalyst,g-C3N4,high performance
更新于2025-09-23 15:23:52
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2D-montmorillonite-dispersed g-C3N4/TiO2 2D/0Dnanocomposite for enhanced photo-induced H2 evolution from glycerol-water mixture
摘要： Montmorillonite (MMT) dispersed g-C3N4/TiO2 hybrid nanocomposite for enhanced photo-catalytic hydrogen production from glycerol-water mixture has been investigated. The newly designed composite photo-catalysts were fabricated through a sol-gel assisted hydrothermal method and were characterized by XRD, XPS, SEM, EDX, TEM, FTIR, UV–Vis, Raman and PL spectroscopy. Well-designed g-C3N4/MMT/TiO2 heterojunction composite was obtained with 2D MMT structure, which promoted both visible light absorption and hindered charges recombination rate. The modification of 2D/0D g-C3N4/TiO2 heterojunction with 2D MMT sheets enhances H2 production due to MMT works as a mediator for effective charges trapping and transportation within the composite structure. The g-C3N4/MMT/TiO2 photo-catalyst exhibits highest H2 production of 4425 ppm h?1 g?1 at pH 7.0, which was 2.12 times higher than the pure TiO2 (2085 ppm h?1 g?1). In addition, increasing catalyst loading promotes more H2 evolution and among the different sacrificial reagents, glycerol-water mixture gave highest H2 production due to the presence of α-hydrogen atoms attached to carbon atoms. The enhanced photocatalytic efficiency can be attributed to synergistic effect of MMT with g-C3N4/TiO2 heterojunction composite, appropriate band structure and transportation of electrons–holes with their hindered recombination rate. These composite catalysts exhibited excellent photo-catalytic stability for H2 production in cyclic runs. Possible reaction mechanism for hydrogen production over g-C3N4/MMT/TiO2 composite has been explained based on the experimental results. The finding of this work would be fruitful for hydrogen production applications with all sustainable systems.
关键词： TiO2,Photo-catalysis,Montmorillonite,g-C3N4,Z-scheme,Hydrogen production
更新于2025-09-23 15:23:52
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2D MOFs enriched g-C3N4 nanosheets for highly efficient charge separation and photocatalytic hydrogen evolution from water
摘要： Here we report a D-2D heterostructure of g-C3N4/UMOFNs photocatalysts via mechanical grinding two kinds of two-dimensional nanosheets of g-C3N4 nanosheets and UMOFNs, which exhibits enhanced H2 evolution from water with simulated solar irradiation. g-C3N4 nanosheets are in close contact with UMOFNs, and there is a certain interaction between them, showing the effect of superimposition on the two-dimensional layer. The 2D-2D heterostructure offers a maximal photocatalytic hydrogen production activity of 1909.02 mmol g-1 h-1 with 3 wt% of UMOFNs, which is 3-fold higher than that of g-C3N4 nanosheets (628.76 mmol g-1 h-1) and 15-fold higher than that of bulk g-C3N4 (124.30 mmol g-1 h-1). The significant increasement of photocatalysis is due to 2D-2D heterostructure possessing a short charge transfer distance and large contact area between g-C3N4 and UMOFNs. The highly dispersed Ni-O, Co-O and p-p bonds in UMOFNs of 2D-2D structure also promote charge transfer and enhance the photocatalytic activity.
关键词： H2 evolution,Photocatalyst,g-C3N4,2D-2D heterostructure,UMOFNs
更新于2025-09-23 15:23:52
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Construction of Pt-decorated g-C3N4/Bi2WO6 Z-scheme composite with superior solar photocatalytic activity toward rhodamine B degradation
摘要： Highly efficient visible-light-driven Pt-decorated g-C3N4/Bi2WO6 hybrid photocatalysts were successfully prepared via a photodeposition method. The microstructures and optical properties of the prepared samples were characterized by transient photocurrent experiments, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-vis diffused reflectance spectra (DRS), photoluminescence (PL), electron spin resonance (ESR) spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. FESEM and TEM images show that metallic Pt particles disperse on the surface of g-C3N4/Bi2WO6 hybrid. Pt-decorated g-C3N4/Bi2WO6 compsites exhibited excellent DRS attribute to the surface plasmonic resonance (SPR) of Pt particles and g-C3N4/Bi2WO6. The PL results verified that the suitable band potential of g-C3N4 and Bi2WO6 for construction of Z-type photocatalytic system. In the photocatalytic experiment, results showed that Pt(1%)-g-C3N4/Bi2WO6 photocatalysts displayed higher photocatalytic activity than either pure g-C3N4 or Bi2WO6 for the degradation of Rhodamine B (RhB). Additionally, the free-radical trapping experiments and ESR disclose that the hole (h+), superoxide radical (·O2-) and hydroxyl radical (·OH) acted as reactive species. Based on above, a possible plasmonic Z-scheme mechanism for organics degradation over Pt-decorated g-C3N4/Bi2WO6 was proposed.
关键词： g-C3N4/Bi2WO6,Visible light irradiation,Z-scheme heterojunction,Pt-decorated
更新于2025-09-23 15:23:52
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Facile preparation of KBiO <sub/>3</sub> /g-C <sub/>3</sub> N <sub/>4</sub> composites with microwave irradiation for photocatalytic hydrogen production
摘要： BACKGROUND: KBiO3/g-C3N4 composites were prepared under microwave irradiation to different weight ratio of KBiO3 (5, 10, 20, 30, 40, 50, 60, 70 80, 90 %wt) using a Mars-6 for 30 min at 100 W. The samples were characterization by XRD, FT-IR, SEM, EDS-Mapping, N2 physisorption and DRS. The photocatalytic activity of the samples was evaluated in the hydrogen evolution reaction. RESULTS: The composites were confirmed by XRD, where was observed that the samples up to 60% of KBiO3 it is easy to identify the characteristic peak of g-C3N4. Composites show that KBiO3 was homogeneously dispersed on g-C3N4 according to what was observed by EDS-Mapping. In the photocatalytic tests was observed that when the concentration of g-C3N4 is greater than KBiO3 but up to a certain limit, there is a higher production of hydrogen. CONCLUSIONS: KBiO3/g-C3N4 composites were prepared successfully with microwave irradiation reaching a good synergy between both materials for hydrogen production reaction. This synergy was improved to the use of microwave that facilitates the dispersion and binding of both materials. The sample with best hydrogen production was 40%KBiO3/60%C3N4 with 698 μmol H2/g, which is about 3 times higher than g-C3N4 and 7 times higher than KBiO3.
关键词： KBiO3/g-C3N4,photocatalysis,hydrogen production,microwave method
更新于2025-09-23 15:23:52
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Photocatalysis removing of NO based on modified carbon nitride: The effect of celestite mineral particles
摘要： Atmospheric NO is one of the toxic and hazardous gases. Its’ levels are continually rising in recent years. As we known, mineral particles contained in the atmosphere may affect the photocatalytic NO removal process. In this study, we found that celestite modification could greatly improve the activity (about 3.8 times) and stability of g-C3N4 for the photocatalytic NO removal. In our system, celestite particles embed in the N vacancies of g-C3N4. The synergistic effect of celestite and N vacancy is the origin of improved NO removal activity. During the light irradiation, photogenerated electrons can be captured and confined by N vacancy. Meanwhile, celestite can transfer these confined electrons to O2 and produce more ·OH, which could oxidize NO to nitrate. These findings can help us to understand the influence of mineral particles in the photocatalytic NO removal and design highly efficient NO removal phtocatalysts.
关键词： NO removal,g-C3N4,Photocatalysis,Celestite,Mineral particles
更新于2025-09-23 15:23:52
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Graphitic Carbon Nitride with Carbon Vacancies for Photocatalytic Degradation of Bisphenol A
摘要： Photocatalysis is intensely employed to remove refractory organic pollutants in water, but suffers from low efficiency due to rapid recombination of photogenerated electrons and holes. Here, carbon vacancies modified g-C3N4 (VC-C3N4) is prepared via a handy two-step calcination method and firstly applied in the photocatalytic removal of bisphenol A (BPA). Compared to pristine g-C3N4, the photocatalytic degradation activity of VC-C3N4 for BPA is largely enhanced, whose kinetic constant (k) of BPA degradation is 1.65 times as that of pristine g-C3N4. The enhanced photocatalytic performance of VC-C3N4 is ascribed to critical role of carbon vacancies: On the one hand, carbon vacancies serve as the reservoir of photogenerated electrons to inhibit the recombination of photogenerated holes and electrons. On the other hand, carbon vacancies as conversion centers transfer trapped photogenerated electrons to absorbed O2 for generation of abundant superoxide radical (?O2-), which takes a dominant effect in the photocatalytic degradation process.
关键词： ?O2- species,bisphenol A,carbon vacancies,g-C3N4,photocatalytic degradation
更新于2025-09-23 15:23:52
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MgO/g-C3N4 nanocomposites as efficient water splitting photocatalysts under visible light irradiation
摘要： A series of MgO/g-C3N4 nanocomposites was prepared by calcination of the mixture of magnesium nitrate hexahydrate and g-C3N4, and applied as photocatalysts for hydrogen evolution from water splitting. The results demonstrate that the MgO/g-C3N4 nanocomposites can effectively harvest sunlight to produce hydrogen from water with higher photocatalytic efficiency than the bare g-C3N4. A high hydrogen evolution rate (HER) of 30.1 μmol h-1 was achieved under visible light for the MgO/g-C3N4 composite loaded with 1 wt% MgO, which is much higher than that of the bare g-C3N4 (5.76 μmol h-1). The enhanced photocatalytic activity of the MgO/g-C3N4 composite could be attributed to the formation of heterojunction between g-C3N4 and MgO that promotes the photo-induced charge carriers' transmission and separation.
关键词： photocatalysis,MgO/g-C3N4 nanocomposite,heterojunction,hydrogen evolution
更新于2025-09-23 15:23:52