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H-bonding Effect of Oxyanions Enhanced Photocatalytic Degradation of Sulfonamides by g-C3N4 in Aqueous Solution
摘要： In this study, the effect of oxyanions on the photodegradation of sulfonamides by graphitic carbon nitride (g-C3N4) was investigated. The results showed that the presence of disilicate (DS) could substantially improve the photodegradation of sulfamethazine (SMZ) in g-C3N4 aqueous suspension. The primary mechanism for the enhancing effect of DS was hydrogen bonding (H-bonding) interaction. The hydroxyl groups (-OH) and bridging oxygen (Si-O-Si) of DS can form H-bonds with the amine groups of g-C3N4 particles and sulfonamides, therefore soluble DS can act as a bridge to enhance the transfer and adsorption of SMZ onto the surface of g-C3N4 particles. The presence of DS did not change the mechanism of photodegradation, but there was an optimal concentration for DS to achieve the strongest enhancing effect. H-bonding effect was also found for other oxyanions derived from weak acids, such as silicate, dihydrogen phosphate and borate ions, because the partial ionization of these oxyanions allowed the existence of hydroxyl groups to form H-bonds. The present study not only deepens our understanding of the interface process of the photodegradation of sulfonamides in g-C3N4 aqueous suspension, but also provides a potential method to enhance the photocatalytic degradation of antibiotics in wastewater streams.
关键词： Carbon nitride,Oxyanions,Photocatalysis,Hydrogen bonding,Sulfonamides
更新于2025-09-09 09:28:46
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Localized Surface Plasmon Resonance Enhanced Photocatalytic Hydrogen Evolution via Pt@Au NRs/C <sub/>3</sub> N <sub/>4</sub> Nanotubes under Visible-Light Irradiation
摘要： Au nanorods (NRs) decorated carbon nitride nanotubes (Au NRs/CNNTs) photocatalysts have been designed and prepared by impregnation–annealing approach. Localized surface plasmon resonance (LSPR) peaks of Au NRs can be adjusted by changing the aspect ratios, and the light absorption range of Au NRs/CNNTs is extended to longer wavelength even near-infrared light. Optimal composition of Pt@Au NR769/CNNT650 has been achieved by adjusting the LSPR peaks of Au NRs and further depositing Pt nanoparticles (NPs), and the photocatalytic H2 evolution rate is 207.0 μmol h?1 (20 mg catalyst). Preliminary LSPR enhancement photocatalytic mechanism is suggested. On one hand, LSPR of Au NRs is beneficial for visible-light utilization. On the other hand, Pt NPs and Au NRs have a synergetic enhancement effect on photocatalytic H2 evolution of CNNTs, in which the local electromagnetic field can improve the photogenerated carrier separation and direct electron transfer increases the hot electron concentration while Au NRs as the electron channel can well restrain charge recombination, finally Pt as co-catalyst can boost H+ reduction rate. This work provides a new way to develop efficient photocatalysts for splitting water, which can simultaneously extend light absorption range and facilitate carrier generation, transportation and reduce carrier recombination.
关键词： synergetic effect,plasmonic photocatalysts,carbon nitride nanotubes,Au nanorods,photocatalytic H2 evolution
更新于2025-09-09 09:28:46
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Rational Design of Graphic Carbon Nitride Copolymers by Molecular Doping for Visible-Light-Driven Degradation of Aqueous Sulfamethazine and Hydrogen Evolution
摘要： Carbon nitride is a promising metal-free visible light driven photocatalyst and sustainable material for address contaminant pollution and water splitting. However, the insufficient visible light absorption and fast charge recombination of carbon nitride have limited its practical application. Herein, the self-assembly carbon nitride (denoted as TCN) by molecular doping copolymerization of urea and 2-thiobarbitucid acid (TA) was prepared. XPS and elemental analytical results indicated that TA was doped in the framework of carbon nitride successfully. The self-assembly copolymerization would result in the change of morphology, intrinsic electron and band structure of carbon nitride. Theoretical calculations and experiments confirm that the band gap of TCN could be adjusted by changing the amount of 2-thiobarbitucid acid. Moreover, the efficiency of charge carrier transfer and separation was greatly enhanced. As a result, the optimized photocatalyst TCN-0.03 exhibited superior activity with a high reaction rate of 0.058 min-1 for the degradation of sulfamethazine under visible light irradiation, which is 4.2 times higher than that of urea based carbon nitride (U-CN). As a multifunctional photocatalyst, TCN-0.03 showed enhanced activity for hydrogen production (55 μmol h-1), which was 11 times higher than U-CN. The apparent quantum efficiency reached to 4.8% at 420 nm. A possible mechanism was proposed to explain the photocatalytic reaction process. This work provides insight into the rational design of modified carbon nitride by other organic monomers copolymerization to enhance the photocatalytic activity.
关键词： Photocatalytic degradation,Photocatalytic hydrogen evolution,Carbon nitride,Charge carriers transfer,Molecular doping copolymerization
更新于2025-09-09 09:28:46
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Visible-light-responsive Photocatalyst of Graphitic Carbon Nitride for Pathogenic Biofilm Control
摘要： Pathogenic biofilms raise significant health and economic concerns, because these bacteria are persistent and can lead to long-term infections in vivo and surface contamination in healthcare and industrial facilities or devices. Compared with conventional antimicrobial strategies, photocatalysis holds promise for biofilm control because of its broad-spectrum effectiveness under ambient conditions, low cost, easy operation, and reduced maintenance. In this study, we investigated the performance and mechanism of Staphylococcus epidermidis biofilm control and eradication on the surface of an innovative photocatalyst, graphitic carbon nitride (g-C3N4), under visible light irradiation, which overcame the need for ultraviolet (UV) light for many current photocatalysts (e.g., titanium dioxide (TiO2)). Optical coherence tomography (OCT) and confocal laser scanning microscopy (CLSM) suggested that g-C3N4 coupons inhibited biofilm development and eradicated mature biofilms under the irradiation of white light-emitting diodes (LEDs). Biofilm inactivation was observed occurring from the surface towards the center of the biofilms, suggesting that the diffusion of reactive species into the biofilms played a key role. By taking advantage of scanning electron microscopy (SEM), CLSM, and atomic force microscopy (AFM) for biofilm morphology, composition, and mechanical property characterization, we demonstrated that photocatalysis destroyed the integrated and cohesive structure of biofilms and facilitated biofilm eradication by removing the extracellular polymeric substances (EPS). Moreover, reactive oxygen species (ROS) generated during g-C3N4 photocatalysis were quantified via reactions with radical probes, and 1O2 was believed to be responsible for biofilm control and removal. Our work highlights the promise of using g-C3N4 for a broad range of antimicrobial applications, especially for the eradication of persistent biofilms under visible light irradiation, including photodynamic therapy, environmental remediation, food industry applications, and self-cleaning surface development.
关键词： graphitic carbon nitride,mechanical properties,extracellular polymeric substances,biofilms,visible light
更新于2025-09-09 09:28:46
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Achieving efficient incorporation of Π‐electrons into graphitic carbon nitride for markedly improved hydrogen generation
摘要： The past decade has witnessed rapid advances in graphitic carbon nitride (g-C3N4) as it is metal-free and affords highly stable hydrogen (H2) generation. Notably, density functional theory calculations show that C-substitution for N in g-C3N4 can increase π-electron availability and in turn significantly the photocatalytic H2 generation. However, creating such C-incorporated g-C3N4 has proven challenging owing to the higher electronegativity of N over C. Here, we report a rapid and highly efficient strategy for introducing C into g-C3N4 by copolymerizing π-electrons-rich barbituric acid with melamine via a facile microwave-assisted heating, thereby eliminating the issues in conventional electric furnace heating, such as the severe volatilization, due to the mismatch on the sublimation temperatures of barbituric acid and melamine. The g-C3 N4 catalyst after optimizing the C-doping content actively generates increased amounts of H2 under visible light exposure with the highest H2 generation rate of 25.0 μmol h-1, nearly 20 times over that using g-C3N4 produced by conventional electric furnace heating of two identical monomers (1.3 μmol h-1). As such, the microwave-assisted heating strategy may stand out as an extremely simple route to incorporating π?electrons into g-C3N4 with markedly improved photocatalytic performance.
关键词： C-incorporation,microwave,carbon nitride,photocatalysis,π?electrons
更新于2025-09-09 09:28:46
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Achieving efficient incorporation of Π-electrons into graphitic carbon nitride for markedly improved hydrogen generation
摘要： The past decade has witnessed rapid advances in graphitic carbon nitride (g-C3N4) as it is metal-free and affords highly stable hydrogen (H2) generation. Notably, density functional theory calculations show that C-substitution for N in g-C3N4 can increase π-electron availability and the photocatalytic H2 generation. However, creating such C-incorporated g-C3N4 has proven challenging owing to the higher electronegativity of N over C. Here, we report a rapid and highly efficient strategy for introducing C into g-C3N4 by copolymerizing π-electrons-rich barbituric acid with melamine via a facile microwave-assisted heating, thereby eliminating the issues in conventional electric furnace heating, such as the severe volatilization, due to the mismatch on the sublimation temperatures of barbituric acid and melamine. The g-C3N4 catalyst after optimizing the C-doping content actively generates increased amounts of H2 under visible light exposure with the highest H2 generation rate of 25.0 μmol h-1, nearly 20 times over that using g-C3N4 produced by conventional electric furnace heating of two identical monomers (1.3 μmol h-1). As such, the microwave-assisted heating strategy may stand out as an extremely simple route to incorporating π?electrons into g-C3N4 with markedly improved photocatalytic performance.
关键词： C-incorporation,microwave,carbon nitride,photocatalysis,π?electrons
更新于2025-09-09 09:28:46
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A brief overview of RF sputtering deposition of boron carbon nitride (BCN) thin films
摘要： A great part of interest has been paid for fabricating new materials with novel mechanical, optical, and electrical properties. Boron carbon nitride (BCN) ternary system was applied for variable bandgap semiconductors and systems with extreme hardness. The purpose of this literature review is to provide a brief historical overview of B4C and BN, to review recent research trends in the BCN synthesizes, and to summarize the fabrication of BCN thin films by plasma sputtering technique from B4C and BN targets in different gas atmospheres. Pre-set criteria are used to discuss the processing parameters affecting BCN performance which includes the gasses flow ratio and effect of temperature. Moreover, many characterization studies such as mechanical, etching, optical, photoluminescence, XPS, and corrosion studies of the RF sputtered BCN thin films are also covered. We further mentioned the application of BCN thin films to enhance the electrical properties of metal-insulator-metal (MIM) devices according to a previous report of Prakash et al. (Opt. Lett. 41, 4249, 2016).
关键词： Radio frequency sputtering,Gas flow ratio,Boron carbon nitride,Metal-insulator-metal device
更新于2025-09-04 15:30:14
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Minireview: Selective production of hydrogen peroxide as a clean oxidant over structurally tailored carbon nitride photocatalysts
摘要： Hydrogen peroxide (H2O2) is a clean oxidant, and its demand has continuously risen in various industries for pulp/paper bleaching, chemical synthesis, wastewater treatment, etc. H2O2 is commercially produced by the anthraquinone method, which has some drawbacks, including (i) toxic solvent, (ii) explosive hydrogen gas as a precursor, and (iii) a high energy input; therefore, a new technology based on cost-effective and green processes is required. Photocatalytic production of H2O2 can be considered the most environmentally benign and economically feasible process because it requires only dissolved oxygen, water, and sunlight. Among various photocatalysts, polymeric carbon nitride (C3N4) is a promising candidate for H2O2 production by virtue of its (i) simple synthesis by a thermal polymerization, (ii) structure consisting of earth-abundant carbon and nitrogen, (iii) effective bandgap size for visible light absorption, and (iv) suitable position of conduction band for reduction of oxygen dissolved in water. In this minireview, the mechanism of H2O2 formation over C3N4 has been discussed, and the strategies to optimize the photocatalytic activity have been summarized regarding structural and surface modification techniques. This overview of diverse methodologies to selectively control electron transfer to dissolved oxygen should be in demand not only for developing new-generation C3N4-based materials, but also for commercialization of solar-light-driven photocatalytic H2O2 production system.
关键词： Hydrogen peroxide,structural modification,Photocatalysis,Carbon nitride,hybridization
更新于2025-09-04 15:30:14
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Fabrication of Perylene Tetracarboxylic Diimide-Graphitic Carbon Nitride Heterojunction Photocatalyst for Efficient Degradation of Aqueous Organic Pollutants
摘要： Metal-free g-C3N4 is the promising candidate for the next generation visible light-responsive photocatalyst, however, high recombination probability of the photogenerated charge carriers on g-C3N4 limits its photocatalytic activity. To further increase the intrinsic photocatalytic activity of g-C3N4, here perylene tetracarboxylic diimide-g-C3N4 heterojunctions (PDI/GCN) are prepared by one-step imidization reaction between perylene tetracarboxylic dianhydride (PTCDA) and g-C3N4 in aqueous solution. By the combination of various testing results it is confirmed that the surface hybridization of PTCDA and g-C3N4 in the PDI/GCN heterojunctions via O=C?N?C=O covalent bonds occurs at lower PTCDA-to-g-C3N4 weight percentage. By selecting p-nitrophenol and levofloxacin as the target organic pollutants, the visible light photocatalytic performance of the PDI/GCN heterojunctions are studied. It shows that the PDI/GCN heterojunction prepared at PTCDA-to-g-C3N4 weight percentage of 1% exhibits remarkably higher visible light photocatalytic degradation and mineralization ability towards aqueous target pollutants as compared with g-C3N4 and Degussa P25 TiO2. On the basis of the experimental results including photoelectrochemistry, indirect chemical probe and electron spin resonance spectroscopy it is verified that the surface hybridization in the heterojunctions is responsible for this enhanced photocatalytic activity via accelerating the migration and separation of the photogenerated charge carriers, causing to produce more active species like ?O2?, hVB+ and ?OH for deep oxidation of PNP or LEV to CO2 and inorganic anions.
关键词： graphitic carbon nitride,heterojunction,perylene tetracarboxylic diimide,visible light photocatalysis,organic pollutant
更新于2025-09-04 15:30:14
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Ultrathin Carbon Nitride with Atomic-Level Intra-Plane Implantation of Graphited Carbon Ring Domain for Superior Photocatalytic Activity in Visible/Near-Infrared Region
摘要： Efficient photocarrier transfer and sufficient light absorption play a crucial role in improving photocatalytic H2 evolution activity. Hence, we report a conceptual design of ultrathin carbon nitride intra-plane implanted with graphited carbon ring domain (CN-GP) via thermal polymerization of polyvinyl butyral and melamine membrane, displaying obvious disparities in the decoration type compared with the adsorption of graphene on the bulk g-C3N4 surface. This unique intra-plane heterostructural CN-GP can greatly sheathe the visible/near-infrared light range, expedite electron-hole pair separation and weaken the barrier of the photocarrier transfer through their suitable energy band structures and in-built electric felds. Consequently, the CN-GP displayed remarkable photocatalytic activity under visible/near-infrared illumination by acquiring a H2 production rate of 11.33 mmol g-1 h-1, and even showed near-infrared-drived photocatalytic activity. This work presents an effective way for the rational fabrication of g-C3N4-based materials for broad-spectrum-driven photocatalysis.
关键词： Intra-plane implantation,Hydrogen production,Vis-NIR,Graphitic carbon nitride,Inter-plane decoration
更新于2025-09-04 15:30:14