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Fabrication of pyrimidine/g-C3N4 nanocomposites for efficient photocatalytic activity under visible-light illumination
摘要： In this work, a series of pyrimidine/g-C3N4 photocatalysts has been synthesized via a facile solvothermal method for the first time. The structure, elemental composition and morphology of the photocatalysts were characterized by FT-IR, SEM, XPS, N2 adsorption-desorption isotherms and BET characterization methods. The photocatalytic activity of the pyrimidine/g-C3N4 materials was investigated by the degradation of rhodamine solution under visible-light illumination. The pyrimidine/g-C3N4 photocatalyst with 1 wt% of pyrimidine shows the highest photocatalytic activity for the degradation of RhB, which can be mainly ascribed to the effective interfacial charge transfer within the pyrimidine/g-C3N4 photocatalyst and the cooperation effect of the excellent contact interface between g-C3N4 and pyrimidine. The main active species during the photodegradation process are determined by the radical trapping experiments, proving that the superoxide radical (?O2-) and the hydroxyl radical (?OH) play the main role in the photocatalytic reactions.
关键词： Photocatalysis,Pyrimidine,Charge transfer,g-C3N4
更新于2025-09-23 15:23:52
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Fabrication of high efficiency visible light Z-scheme heterostructure photocatalyst g-C3N4/Fe0(1%)/TiO2 and degradation of rhodamine B and antibiotics
摘要： We have prepared and studied a novel low cost catalyst of g-C3N4/Fe0(1%)/TiO2, using a simple process involving the formation of zero valence iron by chemical reduction. This ternary catalyst g-C3N4/Fe0(1%)/TiO2 was characterized using XRD (X-Ray diffraction), UV–vis spectrum, EDS (Energy Dispersive spectrum) and TEM (transmission electron microscopy), it demonstrated high-visible-light activity in a wide range of pH condition, it can photo-catalytically degraded Rhodamine B (RhB), Tetracycline (TC), and Berberine hydrogen chloride (BH) (～98% in 90 min) under visible light. The high activity arises from the increased harvest of more visible light and the improved separation of photo-excited electrons and holes via Z-scheme and heterojunctions mechanism. Also, the time required to remove 100% RhB, TC, and 96% BH can be shortened from 90 min to 60 min by introducing 3.18 mM Na2SO3 to this photocatalysis system that assisted the generation of reactive oxidizing species and pollutant degradation. The results showed promising application prospect for this developed catalyst and the tested photocatalysis pollutant degradation system.
关键词： Antibiotics,z-scheme heterostructure,Rhodamine B,g-C3N4/Fe0(1%)/TiO2 photocatalyst,Visible-light
更新于2025-09-23 15:23:52
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Facile fabrication of phosphorus-doped g-C3N4 exhibiting enhanced visible light photocatalytic degradation performance toward textile dye
摘要： Phosphorus-doped graphitic carbon nitride (P-g-C3N4) was facilely fabricated by in situ thermal copolymerization of urea and triphenylphosphine source materials. The P-g-C3N4 exhibited an enhanced photocatalytic performance than pristine g-C3N4 counterpart for the degradation of rhodamine B and acid blue D-2BR textile dye under visible light irradiation. X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption isotherms, X-ray photoelectron spectra (XPS), and diffuse reflection spectroscopy (DRS) techniques were used to characterized the structure and property of P-g-C3N4 photocatalyst. The phosphorus doping enhanced visible light harvesting and surface area, but also substantially changed the electronic property of g-C3N4 material that could suppress the recombination of photogenerated charge carriers, and thus improved photocatalytic performance.
关键词： Textile dye,Porous photocatalyst,Visible light,Degradation,Phosphorus-doped g-C3N4
更新于2025-09-23 15:23:52
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The superior photocatalytic activity of Nb doped TiO2/g-C3N4 direct Z-scheme system for efficient conversion of CO2 into valuable fuels
摘要： In this study, we firstly aimed to use Nb as dopant to dope into the TiO2 lattice in order to narrow band gap energy or enhance photocatalytic activity of the Nb-TiO2. Then, the prepared Nb-TiO2 was combined with g-C3N4 to establish Nb-TiO2/g-C3N4 direct Z-scheme system for superior reduction of CO2 into valuable fuels even under visible light. The obtained results indicated that the band gap energy of the Nb-TiO2 (2.91 eV) was lower than that of the TiO2 (3.2 eV). In the successfully established Nb-TiO2/g-C3N4 direct Z-scheme system, the photo-excited e- in the CB of the Nb-TiO2 combined with the photo-excited h+ in the VB of the g-C3N4 preserving the existence of e- in the CB of the g-C3N4 and h+ in the VB of Nb-TiO2, and thereby, the system produced numerous amount of available e-/h+ pairs for the reduction of CO2 into various valuable fuels. In addition, the produced e- of the Nb-TiO2/g-C3N4 existing in the CB of the g-C3N4, which the potential energy is approximately - 1.2 V, would be strong enough for the reduction of CO2 to generate not only CH4 and CO but also HCOOH. Among established Nb-TiO2/g-C3N4 materials, the 50Nb-TiO2/50g-C3N4 material was the best material for the CO2 reduction.
关键词： Nb dopant,CO2 reduction,Nb-TiO2,g-C3N4,direct Z-scheme
更新于2025-09-23 15:23:52
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Organic/inorganic nitride heterostructure for efficient photocatalytic oxygen evolution
摘要： Given the four-electron water oxidation reaction as the rate-limiting step for water splitting, highly efficient photocatalysts for oxygen evolution have been receiving increasing research attentions. In this study, an organic/inorganic g-C3N4/CoN nitride heterostructure was developed by a facile precipitation-nitridation two-step process. With the CoN loading amounts optimized, the obtained g-C3N4/CoN composite achieves more than 4-fold increase in photocatalytic activity for oxygen evolution, as compared to the pristine g-C3N4, with a highest oxygen evolution rate reaching 607.2 μmol h?1 g?1 under visible light (λ > 420 nm). It was demonstrated that the formed g-C3N4/CoN heterostructure could promote the interfacial charge carrier separation and the loaded CoN acting as an effective cocatalyst could accelerate the water oxidation reaction kinetics, which synergistically contributes to the great enhancement in photocatalytic activity for oxygen evolution. Interestingly, by physically mixing g-C3N4/CoN and g-C3N4/Ni, acting as oxygen and hydrogen production photocatalysts, respectively, the obtained composite could stably produce oxygen and hydrogen in the stoichiometric ratio from pure water under visible light (λ > 420 nm). Although the photocatalytic overall water splitting activity is still very low, this study demonstrates a facile and promising approach to develop visible-light active photocatalysts for simultaneous hydrogen and oxygen production from water, from the perspective of surface modification and bifunctional cocatalyst loading.
关键词： Oxygen evolution,g-C3N4,Photocatalytic water splitting,Heterostructures
更新于2025-09-23 15:23:52
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Enhanced photo-catalytic performance by effective electron-hole separation for MoS2 inlaying in g-C3N4 hetero-junction
摘要： The MoS2/g-C3N4 heterojunction composite (marked as MoS2/g-C3N4-H) was successfully prepared via calcining the melamine coated MoS2 nano-sphere, where the thin g-C3N4 nano-sheets were tightly grown on the surface of MoS2 nano-sphere to form MoS2 inlaying in g-C3N4 heterostructure. The detailed charge transfer mechanism was discussed by combining theoretical calculation and experiments, in which the intrinsic cause of photo-generated charge separation and transfer was determined as the directional built-in electric field driven by different Fermi levels of MoS2 and g-C3N4. Comparatively, the enhanced photo-catalytic performance and stability of the sample were assessed by degrading the Rhodamine (RhB) and reducing the Dichromate (Cr6+) solutions under the irradiation of the simulated sunlight, which could be attributed to the widened spectral absorption range and improved electron-hole separation rate. Based on above results, the photo-catalytic mechanism involving redox reactions was also clearly proposed.
关键词： MoS2,Built-in electric field,Photocatalyst,Heterojunction,g-C3N4
更新于2025-09-23 15:23:52
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Facile assembly of g-C3N4/Ag2CO3/graphene oxide with a novel dual Z-scheme system for enhanced photocatalytic pollutant degradation
摘要： In this study, ternary catalyst g-C3N4/Ag2CO3/graphene oxide was synthesized through a simple chemical precipitation method at room temperature. The CN/AC/GO composite was employed to degrade antibiotics under visible light irradiation. And the results indicated that the composite possessed excellent photocatalytic performance, which could remove 81.6% tetracycline (TC) after 60 min of irradiation. The PL, EIS, PC and UV–vis DRS tests demonstrated that enhanced photocatalytic e?ciency could be attributed to rapid charge transfer, low recombination rate of photo-induced electron-hole pairs, as well as superior light absorption capability. Moreover, three-dimensional excitation-emission matrix ?uorescence spectra (3D EEMs) were employed to further grasp the behaviors of TC molecules in the process of degradation reaction. In addition, the liquid chromatography-mass spectrometry (LC-MS) was carried out to explore the intermediates during the photocatalytic reaction. Meanwhile, the in?uences of initial TC concentration, light source, supporting electrolytes and water sources were explored from the perspective of practical application. Furthermore, the appearance of a small amount of Ag nanoparticles (NPs) not only accelerated the charge transfer, but also improved the stability of catalyst. The composite also possessed high stability and reusability, which were essential in practical application.
关键词： g-C3N4,Double Z-scheme mechanism,Sewage treatment,Photocatalysis
更新于2025-09-23 15:23:52
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Vis-NIR light-responsive photocatalytic activity of C3N4-Ag-Ag2O heterojunction-decorated carbon-fiber cloth as efficient filter-membrane-shaped photocatalyst
摘要： C3N4-decorated carbon-fiber (CF) cloth has been demonstrated to be a filter-membrane-shaped photocatalyst for degrading flowing wastewater, but it can be excited only by visible light (λ < 450 nm). To extend the photoresponse range to NIR region, herein we have designed and prepared C3N4-Ag-Ag2O heterojunctions on CF cloth. The growth of C3N4 nanosheets (thickness: 20-30 nm) on CF cloth is realized by a thermal condensation method, and then Ag/Ag2O nanoparticles (10-20 nm) are deposited on CF/C3N4 cloth by a chemical precipitation method. CF/C3N4/Ag/Ag2O cloth exhibits excellent flexibility and strong photoabsorption in a broad Vis-NIR region (400-1400 nm), wider than CF/C3N4 (absorption edge: 450 nm). Under the irradiation of 808 nm or 980 nm laser, CF/C3N4/Ag/Ag2O cloth can remove 83%/41% AO7 and 72%/38% 4-CP in 140 min respectively, significantly higher than those (33%/13% AO7 and 31%/10% 4-CP) by CF/Ag/Ag2O cloth and those (3%/1% AO7 and 0%/1% 4-CP) by CF/C3N4 cloth. Interestingly, when CF/C3N4/Ag/Ag2O cloth is used as the filter-membrane to photo-degrade the flowing wastewater (AO7, 20 mg L-1, rate: 1.5 L h-1), the removal efficiency of AO7 reaches up 97% after 8 grade reactors. Therefore, CF/C3N4/Ag/Ag2O cloth can be used as an efficient filter-membrane-shaped photocatalyst with NIR photoresponse.
关键词： CF/C3N4/Ag/Ag2O cloth,nanosheets,photocatalysis,nanoparticles,Vis-NIR
更新于2025-09-23 15:22:29
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An Effective Approach to Improve the Photocatalytic Activity of Graphitic Carbon Nitride via Hydroxyl Surface Modification
摘要： In this work, we have developed a hydrothermal method to modify g-C3N4 with hydroxyl surface modification. Modified g-C3N4 has exhibited higher photocatalytic activity in the removal of phenolic compounds under visible light. The improvement may be due to the following merits: (1) Tuning of the hydrophobic surface of g-C3N4 to be hydrophilic; (2) improved adsorption energy, and (3) narrowed band gap for g-C3N4 after hydroxyl surface modification. This method is easy-to-operate, very effective in adding hydroxyl groups on the surface of C3N4, and may be extended to other systems to promote their photocatalytic activities in water treatment.
关键词： water treatment,photocatalysis,hydroxyl,surface modification,g-C3N4
更新于2025-09-23 15:22:29
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Fabricating nano-sized BiVO <sub/>4</sub> /InVO <sub/>4</sub> /g-C <sub/>3</sub> N <sub/>4</sub> photocatalysts for efficient degradation of Acid Blue 92 azo dye
摘要： BiVO4/InVO4 and BiVO4/InVO4/g-C3N4 were prepared by hydrothermal and ultrasonic-assisted hydrothermal methods respectively. All prepared samples were characterised by X-ray diffraction, scanning electron microscopy and UV-Vis diffuse reflectance spectroscopy. The photocatalytic activity of the prepared catalysts was determined by degradation of Acid Blue 92 (AB92) under visible light. The rate constant and efficiency of AB92 degradation over BiVO4/InVO4/g-C3N4 was higher than that over BiVO4/InVO4 which indicates better photocatalytic activity of BiVO4/InVO4/g-C3N4. This enhancement can be attributed to the suitable dispersion of BiVO4 and InVO4 particles on the g-C3N4 surface. Furthermore, the conduction band and valence band edge potentials of InVO4, BiVO4 and g-C3N4 extend the life-time of electron–hole pairs which is beneficial for the improvement of photocatalytic efficiency.
关键词： ternary composites,photocatalysis,dye degradation,materials characterisation,g-C3N4,vanadates
更新于2025-09-23 15:22:29