New Insights into Co-pyrolysis among Graphitic Carbon Nitride and Organic Compounds: Carbonaceous Gas Fragments Induced Synthesis of Ultrathin Mesoporous Nitrogen-Doped Carbon Nanosheets for Heterogeneous Catalysis

Sustainable Electrochemical Synthesis of Porous g-C3N4 Nanosheets via 3D-Printed Platinized Electrodes for Enhanced Photocatalytic Activity

Graphitic carbon nitride (g-C3N4), a polymeric metal-free catalyst, is extensively used to degrade industrial toxic waste that contaminates the aqueous system. However, commonly synthesized bulk g-C3N4 is prone to agglomeration, leading to low surface area with fewer effective photoactive centers, limiting its potential toward the facile separation of photo-excitons and resulting in low photocatalytic activity. This study introduces an innovative electrochemical synthesis of in situ exfoliated porous g-C3N4 nanosheets (GCN NSs) featuring a large surface area with effective separation of photo-excitons, leading to the facile production of reactive oxygen species (ROS). The GCN NSs are uniformly dispersed in an alkaline solution grown via a newly designed electrochemical process using 3D-printed platinumized titanium mesh as both anode and cathode under rigorous stirring for 40 min. The morphological study, along with surface area determination, reveals that the as-grown carbonaceous matrix is highly exfoliated with an inherent nanoporous architecture, having a high surface area of 163.73 m2 g-1 with an average pore diameter of 8.311 nm. The electrochemically synthesized GCN NSs demonstrate excellent charge transfer kinetics with low charge transfer resistance and superior photocatalytic activity of 98% degradation efficiency against various organic dyes (concentration of 10 ppm) under simulated solar irradiation for 120 min with 5 mg of catalyst. Kinetic studies of the photodegradation process indicate that the reaction follows pseudo-first-order kinetics, with the rate constant of 3.59 × 10-2 min-1, which is approximately 1.8 times higher as compared to the recent findings. A plausible mechanistic understanding reveals that photogenerated holes and hydroxyl radicals (•OH) are the primary species for the overall photodegradation process. The stability test depicts that the photocatalyst maintains its efficiency over five consecutive runs with a minimum loss of 7%. This research offers valuable insights into the design and synthesis of advanced photocatalysts with optimized architectures for enhanced industrial waste management.

Cutting-Edge Exploration of a Molecularly Imprinted Polymer-Coupled Electrochemiluminescence Mechanism Based on Organic Cation Side-Chain Construction for the Identification and Detection of Escherichia coli O157: H7

In this paper, an organic semiconductor bacterial biosensor was developed for selective detection of facultative anaerobic Escherichia coli O157: H7, which combines electrochemiluminescence (ECL) and bacterial imprinted polymer technologies. Fe2+ and Mn2+ were used to prepare irregular nanocluster ECL emitters (Fe-Mn NCs) via Cu2O, which served as excellent catalysts in the cathodic coreactant (K2S2O8) reaction system, to enhance the ECL signal intensity. Through electropolymerization, the cationic side chains of functional monomers could bind to proteins (such as cytochrome proteins) on the cell membrane of E. coli O157: H7 under aerobic conditions, and transfer to the interior of E. coli O157: H7 and participate in the cyclic regeneration of nicotinamide adenine dinucleotide, which greatly amplifies the detected ECL signal and accelerates the consumption of oxygen by the respiratory chain. When oxygen was consumed, lactic acid was produced by bacteria during the low-oxygen process, in which E. coli O157: H7 can cause a change in the direction of electron flow, resulting in a reduction in the production of SO4•- and a significant decrease in the ECL signal. And when oxygen was readded to the system, the ECL signal recovers or becomes even stronger, where the mechanism of action of cationic semiconductors in this system had been well elucidated. This sensor has a good linear relationship in the range of 101-108 CFU/mL, with a detection limit of 2.29 CFU/mL (S/N = 3), which offers a new detection method for foodborne pathogens, as well as a rapid and accessible identification tool for different types of microorganisms.

Navigating the evolution of two-dimensional carbon nitride research: integrating machine learning into conventional approaches

Carbon nitride research has reached a promising point in today's research endeavours with diverse applications including photocatalysis, energy storage, and sensing due to their unique electronic and structural properties. Recent advances in machine learning (ML) have opened new avenues for exploring and optimizing the potential of these materials. This study presents a comprehensive review of the integration of ML techniques in carbon nitride research with an introduction to CN classifications and recent advancements. We discuss the methodologies employed, such as supervised learning, unsupervised learning, and reinforcement learning, in predicting material properties, optimizing synthesis conditions, and enhancing performance metrics. Key findings indicate that ML algorithms can significantly reduce experimental trial-and-error, accelerate discovery processes, and provide deeper insights into the structure-property relationships of carbon nitride. The synergistic effect of combining ML with traditional experimental approaches is highlighted, showcasing studies where ML driven models have successfully predicted novel carbon nitride compositions with enhanced functional properties. Future directions in this field are also proposed, emphasizing the need for high-quality datasets, advanced ML models, and interdisciplinary collaborations to fully realize the potential of carbon nitride materials in next-generation technologies.

Picolinamide Functionalization on Carbon Nitride Edges for Enhanced Charge Separation and Photocatalytic Hydrogen Evolution

The periodical distribution of N and C atoms in carbon nitride (CN) not only results in localized electrons in each tri-s-triazine unit, but oxidation and reduction sites are in close contact spatially, resulting in severe carrier recombination. Herein, the hydrothermal method was first employed to synthesize carbon nitride (HCN), and then picolinamide (Pic) molecules were introduced at the edge of the carbon nitride so that the photo-generated electrons of the whole structure of the carbon nitride system were transferred from the center to the edge, which effectively promoted the separation of photo-generated carriers and inhibited the recombination of carriers in the structure. The introduced picolinamide not only changed the π-conjugated structure of the entire system but also acted as an electron-withdrawing group to promote charge transfer. The photocatalytic hydrogen evolution rate (HER) of the optimized HCN-Pic-1:1 sample could reach 918.03 μmolg-1 h-1, which was 11.8 times higher than that of the HCN, and the performance also improved.

In-situ synthesis of heteroatom-doped hard carbon for sodium-ion batteries: Dual benefits for green energy and environment

Heteroatom-doped carbon has been widely investigated as anode materials for sodium-ion batteries (SIBs). However, simplifying the preparation process and precisely controlling their microstructure to achieve excellent Na+ storage performance remain significant challenges. Therefore, in this study, high-performance N, P co-doped Na+ storage carbon anode electrode materials were prepared by one-step carbonization using N, P-rich Eichhornia crassipes (EC) as raw materials and systematically tested for their Na+ storage performance. The doping levels of N and P atoms as well as the spatial structure of the carbon material were adjusted by changing the carbonization temperature during the pyrolysis process. Among them, the anode material corresponding to 1300 °C (EC-PN1300) showed an excellent Na+ storage capacity of 336 ± 4 mAh g-1 (50 mA g-1) and excellent cycling stability (99.8 % retention after 2000 cycles). In addition, the Na+ storage mechanism of EC-PN1300 was systematically analyzed using galvanostatic intermittent titration (GITT), ex-situ XPS and in-situ Raman spectroscopy, providing accurate research directions for developing carbon anode electrode materials with superior electrochemical performance. This study not only provides some insights into the preparation of carbon anode materials in alkali metal batteries and the development of carbon materials in other fields, but also realizes the interaction between environmental protection and new energy development.

Highly selective adsorption of Hg (II) from aqueous solution by three-dimensional porous N-doped starch-based carbon

For the first time, N-doped carbon materials with 3D porous-layered skeleton structure was synthesized through a one-step co-pyrolysis method, which was fabricated by co-pyrolysis of natural corn starch and melamine using metal catalysts (Ni (II) and Mn (II)). The 3D-NC possessed a heterogeneously meso-macroporous surface with a hierarchically connected sheet structure inside. Batch adsorption experiments suggested that highly selective adsorption of Hg (II) by the 3D-NC could be completed within 90 min and had maximum adsorption capacities as high as 403.24 mg/g at 293 K, pH = 5. The adsorption mechanism for Hg (II) was carefully evaluated and followed the physical adsorption, electrostatic attraction, chelation, and ion exchange. Besides, thermodynamic study demonstrated that the Hg (II) adsorption procedure was spontaneous, endothermic, and randomness. More importantly, the 3D-NC could be regenerated and recovered well after adsorption-desorption cycles, showing a promising prospect in the remediation of Hg (II)-contaminated wastewater.