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Long lifetime g-C3N4 photocatalyst coupled with phosphorescent material working under dark condition
摘要： Existing photocatalysts suffer from decreased photocatalytic efficiency when illuminated at wavelengths beyond the UV region or in the absence of irradiation. To overcome this disadvantage, graphitic carbon nitride (g-C3N4), which is responsive to visible light, was coupled with a phosphorescent material (SEAD) that emits green light after irradiation is discontinued. The excited electron and holes in the as-made SEAD/g-C3N4 undergo slow recombination; thus, the material exhibited better performance than g-C3N4 based on photocurrent measurement. We demonstrated the performance of the samples via photodegradation experiments using three organic dyes; methylene blue (MB), methyl orange (MO), and rhodamine B (RhB). The results show that g-C3N4 coupled with the phosphorescent material exhibited better efficiency for photocatalytic degradation of organic dyes than g-C3N4 alone under dark condition as well as light irradiation. In addition, the decomposition of the dyes continued even after irradiation was discontinued, due to phosphorescence.
关键词： graphitic carbon nitride,Photocatalyst,recombination,degradation of organic dyes,phosphorescent material
更新于2025-09-19 17:13:59
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Come to light: detailed analysis of thermally treated Phenyl modified Carbon Nitride Polymorphs for bright phosphors in lighting applications
摘要： Carbon Nitride and its polymorphs have recently gained large interests for their huge properties and applications in different fields, from lighting to photocatalysis. Further, several attempts were recently devoted to tune and control its optical and electrical properties. In this report we analyze phenyl modified Carbon Nitride structures obtained by simple thermal polymerization at different temperatures (250 to 400 °C) of the starting precursor: 2,4-diamino-6-phenyl-1,3,5-triazine. A multi-technique experimental data (XRD patterns, Raman, TGA and DTG, steady- time and time resolved Luminescence, Photoluminescence Excitation spectra, Reflectivity spectra) was applied to analyze the relationship between structural and optical properties and to give more insight on the effect of synthesis procedure on the final polymer. The optical properties evidenced an interesting shift towards the visible region of the absorption spectrum of the phenyl modified g-C3N4 polymer that, associated with the high optical quantum yield (about 60%) and to a broad emission in the green-red spectral region, makes the samples very suitable for lighting applications. Indeed, we report a first prototype of white LED emission by assembly of a commercial blue LED and the Phenyl modified g-C3N4 powders as phosphor, verifying the structural and optical stability over about 10000 working hours.
关键词： Thermal polymerization,Optical properties,Polymorphs,Carbon Nitride,White LED,Lighting applications
更新于2025-09-19 17:13:59
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Quantum-chemical calculations on graphitic carbon nitride (g-C3N4) single-layer nanostructures: polymeric slab vs. quantum dot
摘要： Graphitic carbon nitride (g-C3N4) has been the focus of enormous attention in recent years for its fantastic in-plane and surface properties. Several periodic and cluster models of g-C3N4 including a quantum dot have been investigated using density functional theory (DFT) at the HSE06/Def2-TZVP level. The quantum dot with side triazine rings in nearly perpendicular alignment to the central ring was (by 98.40 kcal/mol) more stable than any other cluster, including its planar analogue—a metastable phase of carbon nitride. The g-C3N4 quantum dot showed the largest deviation (3.27 eV, 7.9%) from the bandgap of the polymeric material. On the other hand, the unrelaxed symmetrical cluster had the smallest deviation (+ 0.03 eV, 1.0%) from the reference bandgap (and also in terms of global hardness), indicating that it could be taken as a replacement cluster for modeling of a polymeric surface in such explorations. The plots of the density of states (DOS) revealed the inherent instabilities of the planar models compared to the quantum dot. Furthermore, the g-C3N4 quantum dot showed the highest chemical hardness among the models investigated. The electronic band structures of the g-C3N4 quantum dot implied its relatively better photoabsorption ability referenced to the polymeric surface. However, the structural changes had significant effects on the orbital and charge distributions in the C3N4 models.
关键词： Semiconductor,Graphitic carbon nitride,Band structure,Sensor,DFT,Quantum dot
更新于2025-09-16 10:30:52
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Enhanced CH4 selectivity in CO2 photocatalytic reduction over carbon quantum dots decorated and oxygen doping g-C3N4
摘要： Graphitic carbon nitride (g-C3N4, CN) exhibits inefficient charge separation, deficient CO2 adsorption and activation sites, and sluggish surface reaction kinetics, which have been recognized as the main barriers to its application in CO2 photocatalytic reduction. In this work, carbon quantum dot (CQD) decoration and oxygen atom doping were applied to CN by a facile one-step hydrothermal method. The incorporated CQDs not only facilitate charge transfer and separation, but also provide alternative CO2 adsorption and activation sites. Further, the oxygen-atom-doped CN (OCN), in which oxygen doping is accompanied by the formation of nitrogen defects, proves to be a sustainable H+ provider by facilitating the water dissociation and oxidation half-reactions. Because of the synergistic effect of the hybridized binary CQDs/OCN addressing the three challenging issues of the CN based materials, the performance of CO2 photocatalytic conversion to CH4 over CQDs/OCN-x (x represents the volume ratio of laboratory-used H2O2 (30 wt.%) in the mixed solution) is dramatically improved by 11 times at least. The hybrid photocatalyst design and mechanism proposed in this work could inspire more rational design and fabrication of effective photocatalysts for CO2 photocatalytic conversion with a high CH4 selectivity.
关键词： carbon quantum dot,photocatalytic,graphitic carbon nitride (g-C3N4),oxygen doping,CO2 reduction
更新于2025-09-12 10:27:22
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Interfacial Engineering in Functional Materials for Dye‐Sensitized Solar Cells || Graphitic Carbon Nitride Based Nanocomposites as Photoanodes
摘要： Owing to their unique properties, nanocomposites, nanostructures, and nanomaterials are playing a key role in energy conversion and in energy storage applications. In recent years, carbon-based nanostructures are used to meet the future energy demands. Nanostructured carbon nitrides (C3N4) are very attractive candidates for energy-based devices due to its high hardness, low friction coefficient, and steadfast chemical inertness. It has a great potential in solving the issues related to energy and environmental applications. Graphitic carbon nitride (g-C3N4) is one among the carbon-based nanostructures which has attracted enormous attention in green technologies for arresting solar energy, energy storage, supercapacitor, fuel cells, electrocatalysis, and environmental remediation as well as for electronic and composite industry. g-C3N4 is a well-known polymeric materials mainly consisting of carbon, nitrogen, and is also one of the oldest material discovered in 1843. It is considered as an artificial polymer in the scientific literature [1]. Its structure is shown in Figure 12.1.
关键词： Nanocomposites,Energy Storage,Energy Conversion,Photoanodes,Graphitic Carbon Nitride
更新于2025-09-12 10:27:22
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5 nm NiCoP nanoparticles coupled with g-C3N4 as high-performance photocatalyst for hydrogen evolution; 负载5 nm磷化钴镍纳米颗粒的石墨相氮化碳高效光催化产氢催化剂;
摘要： Graphitic carbon nitride (g-C3N4) coupled with NiCoP nanoparticles with sizes around 5 nm have been fabricated via a controllable alcohothermal process. NiCoP is an excellent electron conductor and cocatalyst in photocatalytic reactions. The coupling between tiny NiCoP nanoparticles and g-C3N4 through in-situ fabrication strategy could be a promising way to eliminate the light screening effect, hinder the recombination of photo-induced charge carriers, and improve the charge transfer. The NiCoP/g-C3N4 nanohybrids exhibit an excellent photocatalytic activity in the hydrogen generation, with a significantly improved performance compared with original g-C3N4, CoP/g-C3N4 and Ni2P/g-C3N4, respectively. This study paves a new way to design transition metal phosphides-based photocatalysts for hydrogen production.
关键词： nanohybrids,photocatalytic hydrogen generation,carbon nitride,transition metal phosphides
更新于2025-09-12 10:27:22
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Fabrication of a ternary heterostructure BiVO4 quantum dots/C60/g-C3N4 photocatalyst with enhanced photocatalytic activity
摘要： The BiVO4/C60/g-C3N4 ternary heterostructure composite was synthesized by a simple hydrothermal method by loading BiVO4 quantum dots (QDs) onto the surface of C60/g-C3N4, which has excellent photocatalytic activity under visible light irradiation (λ > 420 nm). The BiVO4/C60/g-C3N4 composite oxidatively degraded the organic pollutant Rhodamine B (Rh B) under visible light irradiation, due to the enhanced visible-light harvesting and the increased specific surface area after the addition of BiVO4 QDs. The composite material can effectively inhibit photoinduced electron-hole recombination, improve charge transfer efficiency, and significantly improve photocatalytic efficiency as compared with other single or binary components.
关键词： Photocatalysis,Carbon nitride,C60,Heterostructure,BiVO4
更新于2025-09-11 14:15:04
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Improving Photovoltaic Performance by Using Perovskite/Surface Modified Graphitic Carbon Nitride Heterojunction
摘要： Passivation strategies were considered as one of the most efficient methods to suppress non-radiative recombination of organic-inorganic lead halide perovskite solar cells (PSCs), then, as well as, were widely employed as passivation agents, according to the previous reports. Anchoring g-leading to tremendous photovoltaic performance. An innovative 2D polymer, graphitic carbon nitride (g-C3N4), as well as various organic groups (amino, sulfonic, nitrato and hydroxy group) leading to tremendous photovoltaic performance. C3N4 and the aforementioned organic groups as additives in perovskite could both heal charged defects around the grain boundaries by passivating the charge recombination center. Besides, the crystalline quality could also be enhanced by the incorporation of g-C3N4, leading to improved conductivity of perovskite light absorber films that is beneficial for benign charge extraction efficiency. Inspiring of the underlining mechanisms, we designed a series of novel passivation molecules, functionalized g-C3N4 (F-C3N4) with assorted organic groups, yielding to champion power conversion efficiency (PCE) of 20.08% for NO3-C3N4 based p-i-n structure PSC, in comparison with that of PSC without passivation (17.85%). These findings presented an efficient strategy to understand and design multiple facets of applications of novel passivation molecules to further improve the PCE of PSCs.
关键词： passivation,graphitic carbon nitride,perovskite solar cells,organic groups,photovoltaic performance
更新于2025-09-11 14:15:04
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Nanocomposites based on 3D honeycomb-like carbon nitride with Cd0·5Zn0·5S quantum dots for efficient photocatalytic hydrogen evolution
摘要： Honeycomb-like graphitic carbon nitride (HeC3N4) with unique morphology has been studied as a promising polymer photocatalyst. Herein, a novel binary metal sulfide constructed with HeC3N4 (Cd0·5Zn0·5S/HeC3N4) was prepared though the facile in situ precipitation method. The characterization data suggest that Cd0·5Zn0·5S quantum dots (QDs) are well dispersed on the macroporous structure of HeC3N4 (156 m2 g?1), which can provide higher surface area, more catalytic active sites and larger interface contact area with accelerating the migration and separation of charge carriers. By taking advantage of 0D/3D heterojunction structure, the Cd0·5Zn0·5S/HeC3N4 dramatically boosts the photocatalytic H2 evolution rate with the visible-light illumination. The Cd0·5Zn0·5S/HeC3N4-3 yields the highest photocatalytic activity of 5145 mmol h?1 g?1, which is 4.3 times as high as that of pure Cd0·5Zn0.5S. Furthermore, Cd0·5Zn0·5S/HeC3N4 composite presents high stability after four recycles. The enhanced visible-light-driven photocatalytic H2 production is attributed to the construction of n-n type heterojunction as well as the large surface area, which can inhibit the agglomeration of Cd0·5Zn0·5S nanoparticles, and efficiently transfer the photo-excited electron-hole pairs in Cd0·5Zn0.5S. Therefore, this work provides a potential way for designing advanced 0D/3D heterojunction.
关键词： Heterojunction,Honeycomb-like graphitic carbon nitride,Cd0·5Zn0·5S,Photocatalytic hydrogen generation
更新于2025-09-11 14:15:04
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Single titanium-oxide species implanted in 2D g-C3N4 matrix as a highly efficient visible-light CO2 reduction photocatalyst
摘要： A visible-light-response, efficient and robust photo-catalyst for CO2 reduction is highly desirable. Herein, we demonstrate that single titanium-oxide species implanted in two-dimensional (2D) graphitic carbon nitride (g-C3N4) matrix (2D TiO-CN) can efficiently photo-catalyze the reduction of CO2 to CO under the irradiation of visible light. The synergistic interaction between single titanium oxide species and g-C3N4 in 2D TiO-CN not only enhances the separation of photo-excited charges, but also results in visible light response of single titanium-oxide species, realizing high activity of CO2 photo-reduction with extremely high CO generation rate of 283.9 μmol·h?1·g?1, 5.7, 6.8 and 292.2 times larger than those of TiO2/CN hybrid material, CN and commercial TiO2, respectively. Time-resolved fluorescence and electron spin resonance spectroscopy revealed the catalytic mechanism of the fabricated 2D TiO-CN photocatalysts for CO2 reduction.
关键词： two-dimensional (2D) photocatalysts,graphitic carbon nitride,visible-light,single atom catalyst,CO2 reduction
更新于2025-09-11 14:15:04