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Facile preparation of antifouling g-C3N4/Ag3PO4 nanocomposite photocatalytic polyvinylidene fluoride membranes for effective removal of rhodamine B
摘要： A simplified strategy for facilely fabricating antifouling graphite carbon nitride/silver phosphate (g-C3N4/Ag3PO4) nanocomposite photocatalytic polyvinylidene fluoride (PVDF) porous membranes was developed for effective removal of rhodamine B (RhB). g-C3N4/Ag3PO4 heterojunction was strongly fixed to the interior of the PVDF membranes via phase inversion method. The membrane structure was analyzed by Fourier transform spectrophotometer (FT-IR). The morphology of the prepared membranes was investigated using scanning electron microscopy (SEM), EDX-mapping and atomic force microscopy (AFM), respectively. All prepared nanocomposite photocatalytic PVDF membranes exhibited a typically porous structure, and g-C3N4/Ag3PO4 nanocomposites were well dispersed inside the membranes. The obtained g-C3N4/Ag3PO4 heterojunction nanoparticle decorated PVDF membrane had a lower water contact angle of 79o and higher porosity of 85% than that of other two control membranes. The nanocomposite photocatalytic PVDF porous membranes had extremely high permeation flux over 1,083 L·m?2·h?1, and could be used for the removal of RhB. The removal efficiency of g-C3N4/Ag3PO4-PVDF membranes towards RhB solution under visible light irradiation reached 97%, higher than that of the pure PVDF membranes (41%) and g-C3N4-PVDF membranes (85%). Remarkably, the flux performance and flux recovery ratio (FRR) of membranes revealed that the g-C3N4/Ag3PO4-PVDF membranes could recover high flux after fouling, which presented better fouling resistance. Furthermore, the fabricated antifouling g-C3N4/Ag3PO4 nanocomposite photocatalytic PVDF porous membranes exhibited excellent recyclability. Therefore, it is expected that g-C3N4/Ag3PO4-PVDF membranes could provide an energy-saving strategy for effective removal of organic dyes wastewater and have a great potential for practical wastewater treatment in the future.
关键词： PVDF Membranes,Anti-fouling Properties,g-C3N4/Ag3PO4 Heterojunction,Removal RhB
更新于2025-09-23 15:22:29
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Integrating non-precious-metal cocatalyst Ni3N with g-C3N4 for enhanced photocatalytic H2 production in water under visible-light irradiation
摘要： Photocatalytic H2 production via water splitting in a noble-metal-free photocatalytic system has attracted much attention in recent years. In this study, noble-metal-free Ni3N was used as an active cocatalyst to enhance the activity of g-C3N4 for photocatalytic H2 production under visible-light irradiation (λ > 420 nm). The characterization results indicated that Ni3N nanoparticles were successfully loaded onto the g-C3N4, which accelerated the separation and transfer of photogenerated electrons and resulted in enhanced photocatalytic H2 evolution under visible-light irradiation. The hydrogen evolution rate reached ~305.4 μmol h?1 g?1, which is about three times higher than that of pristine g-C3N4, and the apparent quantum yield (AQY) was ~0.45% at λ = 420 nm. Furthermore, the Ni3N/g-C3N4 photocatalyst showed no obvious decrease in the hydrogen production rate, even after five cycles under visible-light irradiation. Finally, a possible photocatalytic hydrogen evolution mechanism for the Ni3N/g-C3N4 system is proposed.
关键词： Hydrogen evolution,g-C3N4,Cocatalyst,Ni3N,Photocatalysis
更新于2025-09-23 15:22:29
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In situ derived Ni2P/Ni encapsulated in carbon/g-C3N4 hybrids from metal–organic frameworks/g-C3N4 for efficient photocatalytic hydrogen evolution
摘要： Tightly coupling multiple cocatalysts into semiconductors for efficient charge separation is a promising way to enhance photocatalytic H2 production. In this work, Ni2P/Ni nanoparticles (NPs) encapsulated in carbon/g-C3N4 hybrids derived from in situ pyrolysis and phosphidation of Ni-based metal-organic frameworks/g-C3N4 (Ni-MOF/g-C3N4) precursor were used as photocatalysts for H2-evolution under visible-light irradiation. The highest H2-evolution rate over optimized Ni2P/Ni@C/g-C3N4-550 was 18.04 mmol g?1 h?1 with 1.0 mmol L?1 of Eosin Y (EY)-sensitization (compared to 0.21 mmol g?1 h?1 without EY-sensitization), 13 times higher than that of pristine g-C3N4 (1.33 mmol g?1 h?1). The apparent quantum efficiency at 420 nm was 58.1%. This enhanced photocatalytic activity can be attributed to an efficient and rapid separation of the photo-generated charges from excited EY and g-C3N4 to Ni2P/Ni with carbon as an electron transport bridge, intimate contact of each components, staggered band alignment among g-C3N4, Ni and Ni2P, as well as accelerated proton reduction reaction by Ni2P/Ni NPs. This work provides new insights into the construction of MOFs-derived cocatalyst for photocatalytic H2 production.
关键词： H2 evolution,g-C3N4,Ni-MOF-derived,carbon materials,Ni2P/Ni
更新于2025-09-23 15:22:29
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Introduction of Nitrogen Defects into a Graphitic Carbon Nitride Framework by Selenium Vapor Treatment for Enhanced Photocatalytic Hydrogen Production
摘要： Graphitic carbon nitride (g-C3N4) is a metal-free semiconductor photocatalyst that has attracted significant attention due to its promising application in photocatalytic hydrogen production. However, pristine g-C3N4 suffers from a high recombination rate of photo-generated charge carriers and also has a limited visible-light absorption range, resulting in low photocatalytic activity. Herein, we report on the preparation and testing of a g-C3N4 photocatalyst with tunable nitrogen defects that delivered improved photocatalytic activity. The nitrogen defects were gradually introduced into the g-C3N4 framework by a selenium vapor treatment of pure g-C3N4, which resulted in improved, stable catalytic activity for photocatalytic hydrogen production. Based on the experimental results and DFT calculations, we proposed that the enhanced photoactivity is attributed to the defect state (DS) formed by the nitrogen vacancy (VN) in the unit cell of g-C3N4 and a small widening of visible light absorption. This nitrogen-based photocatalyst with nitrogen deficiencies was found to deliver an average hydrogen generation rate of 1.16 mmolg-1h-1 at room temperature (25 oC), which was 3.4 times greater than pristine g-C3N4. This process of introducing nitrogen defects into the graphitic carbon provides a promising way for enhancing the photocatalytic activity of g-C3N4-based materials for hydrogen production.
关键词： nitrogen vacancies,photocatalytic hydrogen production,g-C3N4,bandgap
更新于2025-09-23 15:22:29
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Gaseous bubble-assisted in-situ construction of worm-like porous g-C3N4 with superior visible light photocatalytic performance
摘要： Metal-free graphitic carbon nitride (g-C3N4) displays benign photocatalytic properties for contaminants photodegradation under visible photoirradiation. Devising a simple modification strategy for the improved photocatalytic activity of g-C3N4 has always been desired. Herein, we report a spherical worm-like g-C3N4 nanostructure via facile ammonium lauryl sulfate (ALS) gaseous bubbles templating approach. This strategy employing ALS as gaseous bubbles templating agent bestowed not only g-C3N4 with improved specific surface areas, a porous structure with more exposed photocatalytic reactive sites and mass diffusion of reactants molecules, but also rendered extended optical absorption range and suppression of the photoinduced charge carriers recombination. As a result, the ALS-mediated g-C3N4 photocatalysts unfolded excellent photocatalytic performance regarding photodegradation of rhodamine B (RhB) and phenol under visible photoirradiation. Additionally, the quenching effects of various scavengers proved that the holes (h+) and superoxide anions (?O2-) radicals were the main active species responsible for ameliorated photocatalytic performance for rhodamine B and phenol photodegradation. Our work offers a straightforward approach for developing high-performance metal free photocatalysts with great potential for environmental remediation.
关键词： Ammonium lauryl sulphate,g-C3N4,Photocatalytic activity,Porous,Gaseous bubbles
更新于2025-09-23 15:22:29
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A facile synthesis of nano-layer structured g-C3N4 with efficient organic degradation and hydrogen evolution using a MDN energetic material as the starting precursor
摘要： The construction of a high-performance g-C3N4 photocatalyst through a facile and green synthesis method remains a great challenge for H2 production and organic pollutants degradation. In this work, we developed a nano-layer structured g-C3N4 (NL-CN) photocatalyst with a 230 m2/g surface area via the thermal polymerization method using melaminium dinitrate (MDN), which is one of the more energetic materials, as the precursor. The energy coming from the drastic decomposition of nitrate anions in MDN caused the thick layers of bulk CN to be exfoliated to produce many much-thinner nano-layers when at 500 °C for 2 h, which obviously elevated the surface area of the g-C3N4. The resultant NL-CN displays a superior visible-light H2-generation and rhodamine B (RhB) photo-degradation efficiency (λ > 420 nm) compared to those of bulk g-C3N4 (CN) prepared through heating melamine because of the nano-layered structures, which lead to higher specific surface areas, a rapid charge transfer efficiency and a higher redox potential. These results demonstrate that the utilization of MDN as a starting material provides a new opportunity for the facile and green synthesis of high-efficiency nanostructured g-C3N4 photocatalysts with lower energy consumption and environmental pollution levels.
关键词： H2 production,Nano-layers,Melaminium dinitrate,g-C3N4,Photocatalyst,RhB degradation
更新于2025-09-23 15:22:29
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A high-performance fluorescent probe for dopamine detection based on g-C3N4 nanofibers
摘要： A novel fluorescent sensor based on g-C3N4 nanofibers for the sensitive detection of dopamine (DA) has been proposed. We synthesized g-C3N4 nanofibers by directly hydrolyzing bulk g-C3N4 in the alkaline atmosphere (3 M NaOH). The obtained ultrathin g-C3N4 nanofibers were verified by characterizations of Transmission electronic microscope (TEM), X-ray diffractometer (XRD), Fourier transformation-infrared (FT-IR) and X-Ray photoelectron spectroscopy (XPS). It was found that the fluorescence intensity of g-C3N4 nanofibers was obviously quenched by DA. Fluorescence resonance energy transfer (FRET) between DA and g-C3N4 nanofibers led to the fluorescence reduction of g-C3N4 nanofibers. The fluorescent probe based on g-C3N4 nanofibers exhibits linear responses to the concentration of DA in the range from 0 to 4 μM and 4 to 20 μM, the limit of detection is 17 nM. The fluorescent probe shows excellent stability, good selectivity with its application in serums.
关键词： dopamine,g-C3N4 nanofibers,quenching,fluorescent probe
更新于2025-09-23 15:22:29
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Facile two-step synthesis of porous carbon nitride with enhanced photocatalytic activity using a soft template
摘要： In this study, we successfully synthesized a thin-slice layer of graphitic carbon nitride (g-C3N4) with abundant irregular holes by a facile two-step way using Pluronic P123 as a template (CN-P123-x, where x represents the mass ratio of melamine to Pluronic P123). The characterization data suggest that the introduction and removal of Pluronic P123 altered the chemical material structure of the carbon nitride. The CN-P123-x presented lamellar structure with irregular holes, whereas H-g-C3N4 (g-C3N4 prepared using a mild hydrothermal and calcination method without Pluronic P123 or HCl) has a dense blocky structure. Additionally, the prepared CN-P123-x exhibited an effective Rhodamine B (RhB) degradation rate of 98.7% within 40 min of illumination. The optimal photocatalytic activity of CN-P123-6 for degrading RhB was 13.9 times greater than that of H-g-C3N4 in terms of the kinetic constant. Furthermore, the H2 evolution rate of CN-P123-6 can reach 1074.9 μmol?g?1?h?1, whereas that of H-g-C3N4 is only 3.1 μmol?g?1?h?1. It is worth noting that the adoption of HCl (H-g-C3N4-HCl) and Pluronic P123 (CN-P123-6 without HCl) alone has no insignificant effect on photocatalytic performance. The intensive activities are on account of the irregular pores in the thin slice, which increase the specific surface area of the sample and provide additional active sites for reaction. This work provides an excellent basis for improving the performance of the photocatalytic degradation and hydrogen production of carbon nitride.
关键词： Rhodamine B (RhB),H-g-C3N4,hydrogen production,photocatalytic degradation,CN-P123-x
更新于2025-09-23 15:22:29
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Recent Development of Photocatalysts Containing Carbon Species: A Review
摘要： Undoubtedly, carbon-based (nano)composites can be promising photocatalysts with improved photocatalytic activity due to the coupling effect from the incorporation of carbon species. In this mini-review, we focus on the recent development of photocatalysts based on carbon-based (nano)composites. TiO2 is well-known as a typical photocatalyst. Special attention is paid to the various types of carbon–TiO2 composites such as C-doped TiO2, N–C-doped TiO2, metal–C-doped TiO2, and other co-doped C/TiO2 composites. Various synthetic strategies including the solvothermal/hydrothermal method, sol–gel method, and template-directed method are reviewed for the preparation of carbon-based TiO2 composites. C/graphitic carbon nitride (g-C3N4) composites and ternary C-doped composites are also summarized and ascribed to the unique electronic structure of g-C3N4 and the synergistic effect of the ternary interfaces, respectively. In the end, we put forward the future perspective of the photocatalysts containing carbon species based on our knowledge.
关键词： (nano)composites,synergistic effect,g-C3N4,C-doped,photocatalysts,TiO2
更新于2025-09-23 15:22:29
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Ag3PO4 modified phosphorus and sulphur co-doped graphitic carbon nitride as a direct Z-scheme photocatalyst for 2, 4-dimethyl phenol degradation
摘要： Very recently, hybrid photocatalysts are gaining importance due to their unique and enhanced photocatalytic activity. In precedent study, we have successfully prepared Ag3PO4 (AP) and P and S co-doped g-C3N4 (PSGCN) based AP/PSGCN photocatalyst via facile deposition-precipitation method. The P and S co-doped g-C3N4 was prepared via thermal poly-condensation using hexachlorotriphosphazene (HCCP) and thiourea as precursors. The photocatalysts were characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). The thickness of AP/PSGCN was less than 9.0 nm. The zeta potential and Tyndall effect experiments validated the formation of well dispersed suspension of AP/PSGCN in water. The co-doping resulted in lowering of optical band gap of g-C3N4. The Tyndall effect experiments ascertained the formation of well dispersed suspension of AP/PSGCN. The photoluminescence and electrochemical impedance analysis confirmed reduction in recombination of photogenerated electron and hole pairs. The photodegradation of 2,4-dimethyl phenol (DMP) followed pseudo first order kinetics. The enhanced photocatalysis was due to direct Z-scheme mechanism. Hydroxyl and superoxide radicals were the two main reactive species during DMP degradation. The COD, HPLC and LC-MS investigations ascertained mineralization of DMP. AP/PSGCN displayed high stability and recycle efficiency significant for ten catalytic cycles.
关键词： DMP,Ag3PO4,P and S Co-doped g-C3N4,Nanocomposite,Z-scheme photocatalysis
更新于2025-09-23 15:22:29