Synthesis Of Nitride Research Articles

Engineering Planar Crystallinity in Nitrogen-Vacancy-Incorporated Carbon Nitride for Efficient Photoredox Catalysis.

The concurrent evolution of value-added benzimidazole compounds and hydrogen within the domain of chemical synthesis is of paramount importance. The utilization of photocatalysis enhances both the efficiency and environmental benignity of the synthetic process. However, it is profoundly challenging within a photocatalytic system to simultaneously augment the number of active sites and the internal transport rate of photogenerated charge carriers. To address this issue, a template-free, step-by-step assembly strategy has been proposed for the synthesis of planar crystalline carbon nitride (CCN) incorporated with a nitrogen vacancy (Nv). In contrast to the simultaneous assembly method, the sequential assembly process encompasses a progressive crystallization mechanism. This method is conducive to the mitigation of the incidence of structural disarray, thereby precluding the genesis of non-ordered defects throughout the whole bulk phase. The ordered in-plane arrangement facilitates the spatial segregation of electrons and holes, thereby decoupling the redox active sites. This separation minimizes the likelihood of back reactions and suppresses the recombination process, which is advantageous for the efficiency of photocatalytic coupling reactions. Certified by multiscale characterization and theoretical simulations, the incorporation of Nv enhances the energy band structure and provides sites with unsaturated coordination for the adsorption and activation of ethanol molecules. This interfacial synergistic effect of Nv and co-catalyst Pt as the Lewis site achieves efficient activation of both coupling partners. The obtained CCN demonstrates significant bifunctional photocatalytic activity, achieving a yield of benzimidazole at 5.0 mmol g-1 with a conversion and selectivity rate of 99%. Simultaneously, the hydrogen evolution rate of CCN is measured at 9.1 mmol g-1 within 4 h. The template-free, step-by-step assembled strategy utilized in this study provides new perspectives on developing highly efficient photocatalysts at the molecular level.

SYNTHESIS OF VANADIUM GRAPHITIC-CARBON NITRIDE(V/g-C₃N₄) COMPOSITE FOR BIOLOGICAL APPLICATION

The synthesis of vanadium carbon nitride (V/g-C₃N₄) composites has been explored for their potential as antimicrobial and antioxidant agents. These materials were evaluated against Escherichia coli and Staphylococcus aureus using a combination of disc diffusion, well diffusion, and biofilm inhibition assays. Antioxidant properties were assessed through DPPH free radical scavenging analysis. V/g-C₃N₄ composites demonstrated notable antimicrobial activity, exhibiting inhibition zones comparable to ciprofloxacin, the standard antibiotic. In disc and well diffusion assays, the composites significantly inhibited the growth of both bacterial strains, with Staphylococcus aureus exhibiting marginally higher sensitivity. Biofilm inhibition assays revealed effective suppression of bacterial adhesion and biofilm formation, achieving biofilm inhibition percentages of approximately 17% for E. coli and 22.6% for S. aureus. These results underscore the potential of V/g-C₃N₄ in curbing biofilm-associated infections. Antioxidant activity was quantitatively measured using the DPPH assay, with radical scavenging efficiency consistently exceeding 52%. This performance highlights the dual functionality of V/g-C₃N₄ composites as both antimicrobial and antioxidant agents. Comparatively, ciprofloxacin demonstrated superior antibacterial activity but lacked antioxidant properties, emphasizing the multifaceted advantage of V/g-C₃N₄ composites in biomedical applications. The shake-flask method further validated the biocompatibility and antimicrobial effectiveness of V/g-C₃N₄. This study indicates that vanadium carbon nitride composites hold promise as versatile agents in combating oxidative stress and bacterial infections, particularly in environments where biofilm formation exacerbates antimicrobial resistance. Future studies will focus on optimizing the composite synthesis and exploring its efficacy against a broader range of pathogens.

Recent progress in synthesis and properties of two-dimensional boron carbon nitride for application in energy storage devices

Abstract Two-dimensional (2D) Boron Carbon Nitride (BCN) has recently gained significant attention as a convoluted ternary system owing to its remarkable capability to exhibit a wide range of finely tunable physical, chemical, optical, and electrical properties. In this review, we discuss a variety of stable structure forms of BCN nanosheets. In addition, this review provides recent approaches for synthesizing BCN nanostructures, and properties of BCN derivatives. BCN is a promising material for sustainable energy and energy storage devices. Since BCN application is a challenge in the field of energy, we present potential applications of BCN in the field of energy including supercapacitors and batteries, wastewater treatment, electrochemical sensing, and gas adsorption.

Synergistic photocatalytic degradation of methylene blue and ibuprofen using Co₃O₄-Decorated hexagonal boron nitride (hBN) composites under Sun-like irradiation.

In this study, we report the synthesis and photocatalytic performance of Co₃O₄-decorated hexagonal boron nitride (hBN) composites for degrading methylene blue (MB) and ibuprofen (IBF) under sunlight irradiation. Using a dry impregnation method, the composites were prepared with varying Co₃O₄ loadings (0.5%, 1%, 2%). Comprehensive characterization confirmed the successful incorporation and uniform distribution of Co₃O₄ on the hBN matrix. Photocatalytic experiments revealed that 1% Co₃O₄-hBN composite exhibited the highest activity, achieving nearly 100% MB degradation in 60min and 90% IBF degradation in 120min. The enhanced photocatalytic efficiency is attributed to the synergistic effects between Co₃O₄ and hBN, which extend light absorption and promote charge separation. Our findings demonstrate the potential of Co3O₄-decorated hBN composites as effective photocatalysts for environmental remediation. The study provides a foundation for further exploration of these materials, including their long-term stability and application to a broader range of pollutants.

Facile vacuum annealing of thiourea-induced synthesis of graphitic carbon nitride for the efficient adsorption of anionic dyes

Facile vacuum annealing of thiourea-induced synthesis of graphitic carbon nitride for the efficient adsorption of anionic dyes

Synthesis of monolayer tungsten nitride: Rapid optical visualization and electrical impact of grain boundaries

Synthesis of monolayer tungsten nitride: Rapid optical visualization and electrical impact of grain boundaries

Preparation and Growth Mechanism of Hexagonal Boron Nitride in the Presence of Lithium Oxide

AbstractThe synthesis of hexagonal boron nitride (h‐BN) by the reaction of boron oxide (B2O3) and NH3 represents an environmentally friendly and economical preparation process. Employing a catalyst to improve the issues including low conversion and reaction rate is important to facilitate the implementation of this method. In this study, we studied the effect of adding lithium oxide (Li2O) with a mass fraction of 14%–25% on the reaction process between B2O3 and NH3 at 1000–1200 °C. During the reaction process, Li2O reacts with B2O3 to form a lithium borate melt. The lithium borate melt facilitates the diffusion of NH3, and benefits to the dissolution and precipitation of BN, thus promoting the growth of h‐BN. A nearly complete conversion to h‐BN was observed by adding Li2O with a mass fraction of 17% when heating at 1200 °C for 240 min. The products exhibit good crystallinity (graphitization index of 3.4) and a sheet structure, with a thickness of 32 nm and a diameter of 400–500 nm. These results provide a reference for optimizing the preparation process of h‐BN.

Hydrothermal Synthesis of Graphitic Carbon Nitride Nanocluster and Study of its Photoluminescence Properties

In the present scenario of modern urbanization there is an increasing demand of different opto-electronic devices that includes light emitting diodes, photo conductors or many others. From this point of view finding a cheap material with high luminescence efficiency is of extreme important. Along with possessing high radiative recombination efficiency the optoelectronic material should be cost effective as well and at the same time it should be synthesized with high yield. Keeping this in mind, this study presents the synthesis of fractal-like graphitic carbon nitride (GCN) nanostructures via a, low-temperature hydrothermal method. The synthesized material was characterized using various techniques where X-ray diffraction (XRD) confirmed proper phase formation, while field emission scanning electron microscopy (FESEM) revealed its fractal like morphology. UV-Vis reflectance spectra, along with the Kubelka-Munk plot, confirmed that the band gap of the material is around 3 eV and thus comes within the violet-blue range. Fourier-transform infrared (FTIR) spectroscopy provided insights into the different vibrational energy levels present in the sample. Photoluminescence (PL) analysis shows strong PL signal at 431 nm and thus corresponds to band to band transition. The findings indicate this fractal-like GCN has the potential to be used as optoelectronic device.

Carbon-Doped Hexagonal Boron Nitride as a Catalyst for Efficient Degradation via Non-Radical Pathway

The escalating challenge of high-salinity organic wastewater has prompted the development of persulfate-based advanced oxidation processes (AOPs) for the effective degradation of pollutants. This study presents the synthesis and application of a carbon-doped hexagonal boron nitride (C-hBN) catalyst, which is designed to activate peroxymonosulfate (PMS) efficiently under high-salinity conditions. The C-hBN catalyst is prepared through a two-step process using dopamine as the carbon source, resulting in a uniform doping of carbon and the formation of B-N-C bonds. The catalyst exhibits a significantly enhanced specific surface area and superior catalytic performance towards phenol degradation, with a rate constant of 0.74 min−1. Under high-salinity conditions, the C-hBN catalyst demonstrates robust resilience against common ions, maintaining high catalytic activity. The degradation process is primarily driven by a non-radical pathway, with singlet oxygen (1O2) identified as the key reactive species. This work provides valuable insights into the development of metal-free catalysts for environmental remediation and offers a promising strategy for the treatment of organic pollutants in high-salinity wastewater.

NEW SAFETY CHALLENGES OF CEMENT-CONTAINING BUILDING MATERIALS AND PRODUCTS FROM THEM

The article considers a new problem of harmful effects of Portland cement on humans due to the possibility of releasing ammonia during hydration hardening of materials and products based on it. It notes the relationship between the analyzed problem and the intensification of energy and resource saving at modern cement plants, which allows nitrogen-containing materials to enter Portland cement: as part of raw materials; with materials utilized in high-temperature zones of rotary kilns and as part of additives introduced during grinding of cement clinker. Probable sources of ammonia release from Portland cement during its hydration are analyzed in a logical sequence and taking into account the chemical specificity of various groups of nitrogen-containing compounds. The most theoretically substantiated and experimentally confirmed hypothesis is chosen about the synthesis of iron nitrides in high-temperature zones of rotary kilns for burning cement clinker – the main sources of subsequent ammonia emission during hydration of Portland cement. A set of conditions necessary for the synthesis of iron nitrides is considered. The debatable nature of the issue of the stability of stoichiometric iron nitride Fe8N is indicated and it is proposed to consider it as a solid solution along with stoichiometric compounds Fe4N and Fe2N when analyzing chemical processes of hydration with the formation of ammonia. Possible solutions to the problem at the place of its occurrence - Portland cement plants – are discussed. The expediency of depleting sources of ammonia emission at the initial stages of hydration hardening of Portland cement is shown, which significantly reduces the risk of harmful effects on the human body. A method for eliminating the problem at large enterprises consuming Portland cement in significant quantities for the manufacture of dry building mixtures, concrete and products from them is selected. The essence of the method for proactively removing the main amount of ammonia emission sources at the initial stage of Portland cement hydration in the presence of the additive Ca(NO3)2 is described. Theoretical and practical arguments are presented about the positive effect of small amounts of Ca(NO3)2 on the formation of the microstructure and operational characteristics of cement stone, which additionally stimulates the implementation of the proposed method. The need for a comprehensive large-scale study of all possible manifestations of the analyzed problem with the involvement of specialists from sanitary and hygienic services is emphasized.

DC reactive sputtering synthesis of titanium nitride coatings on titanium for biomedical applications

DC reactive sputtering synthesis of titanium nitride coatings on titanium for biomedical applications

Molten salt-assisted synthesis of boron-doped carbon nitride for photocatalytic hydrogen evolution.

In this work, B and K were introduced into the heptazine structure of carbon nitride to synthesize the catalyst kalium-boron doped carbon nitride (KBCN) with a larger light absorption range and improved photogenerated carrier separation rate. Boron atoms are introduced into the carbon nitride heptazine units to optimize the electronic structure within the carbon nitride planes, and the B-N bonds formed by the heptazine units facilitate charge transfer. Potassium atoms are introduced into the carbon nitride interlayer as charge transfer channels to synergistically promote the transfer of photogenerated electrons. This work provides a potential idea for the doping of metallic and nonmetallic elements to jointly promote the charge distribution and transfer of carbon nitride.

Efficacy of nickel doped graphitic carbon nitride as energy storage material

Abstract The current article reports the synthesis of graphitic carbon nitride (GCN), through simple thermal decomposition of urea at a moderate temperature of 550 °C and doping of as-developed material with transition element like nickel. The proper phase formation of the sample was confirmed by x-ray diffraction whereas electron microscopic images analyzed the sample morphologies. The successful doping was verified by x-ray photoelectron spectroscopy whereas thermogravimetric study predicted the stability of the material under elevated temperature. Fourier transformed infrared spectroscopy showed that after Ni doping there is a substantial change in the vibrational energy level of the sample. UV–vis reflectance spectra confirmed the reduction of optical bandgap after metal doping. The samples show promises towards supercapacitor application. Cyclic voltametric study shows that after metal doping the value of specific capacitance became 162 Fg−1 at scan rate 5 mV s−1 and when the same was calculated from galvanostatic charging–discharging characteristics the values came even higher. The energy and power density of both the samples was calculated and all these when compared with different reported results, confirmed the performance of Ni doped GCN is comparable and sometimes even far better along with the advantages of the easy, large scale and high yield synthesis approach.

Facile single-pot synthesis of Fe-doped nitrogen-rich graphitic carbon nitride (Fe2O3/g-C3N4) bifunctional photocatalysts derived from urea for white LED-mediated Aldol condensation reaction

Facile single-pot synthesis of Fe-doped nitrogen-rich graphitic carbon nitride (Fe2O3/g-C3N4) bifunctional photocatalysts derived from urea for white LED-mediated Aldol condensation reaction

Unraveling symmetric hierarchy in solid-state reactions of tungsten-based refractory metal carbides through first-principles calculations

Refractory metal carbides, usually fabricated via solid state reactions, require precise control of their reactants and temperature, especially when they enter a complex compositional space, like high-entropy (multi-component) carbides. In this work, the solid-state reactions of tungsten based refractory metal carbides M-W-C (M = Ti, Zr, Hf, V, Nb, Ta) are systematically studied through first-principles thermodynamic calculations and percolation simulations, and its relationship with symmetric principles is unraveled. Symmetric hierarchy is defined by the group-subgroup Bärnighausen tree and the gap in their space group number. It suggests MC and WC/W2C are two possible reactants to form the highest symmetric M-W-C ternary carbides, and indicates the larger the gap in their space group number, the harder the reactions. From the symmetric hierarchy, we found the reaction path from MC to M-W-C ternary carbides is the most probable, supported by the Gibbs reaction free energy. Carbon percolation within the metal framework plays another role in the solid-state reactions of tungsten based refractory metal carbides. It reveals the phase transition from M6W6C to M3W3C undergoes a transient M2W2C. The success in predicting the phase relationship of M-W-C ternary system offers a new paradigm for the design and synthesis of high-entropy carbides, nitrides, and oxides.

Developing Graphitic Carbon Nitride for Effective Treatment of Organic Pollutants in Industrial Water

Organic pollutants, including pesticides and industrial waste, have become a significant environmental challenge due to their persistence and difficulty in decomposition, posing serious threats to both environmental health and water quality. This issue is particularly pressing in regions like Penang, where rapid industrial development and urbanization have exacerbated water pollution. In response, various research efforts have explored potential solutions, with graphite emerging as an effective adsorbent for removing toxic compounds from water. Building on this, our study focuses on the synthesis of graphitic carbon nitride (g-C3N4), a material recognized for its high-performance photocatalytic properties. g-C3N4's unique structure and ability to harness solar energy make it a promising candidate for catalyzing the breakdown of organic pollutants into less harmful molecules. Our project aims to develop a cost-effective and scalable method for producing g-C3N4 using readily available materials, with the goal of mitigating organic pollution in Penang. Through a straightforward synthesis process, we seek to make this technology accessible for widespread adoption in water treatment practices. The successful synthesis of g-C3N4 has already been demonstrated, with the process being effectively shared with students from the School of Chemical Science at USM. While further refinements are needed to maximize results, our findings suggest that g-C3N4 can play a crucial role in reducing organic pollution and improving water quality, contributing to the long-term sustainability of Penang's environment.

One pot synthesis of donor-acceptor carbon nitride with distinct thiophene rings accelerate photocatalytic hydrogen evolution

Graphitic carbon nitride (g-CN) with a donor-acceptor structure was synthesized by urea and cross-linking thiophene precursors at the terminal sites, achieved through calcination of urea with four different thiophene-based precursors under atmospheric conditions. Among these, UDB-2-1, which incorporates dibenzothiophene-2-carboxyaldehyde (DB-2) 1 mg, demonstrated a hydrogen evolution activity of 650 μmol/g·h, approximately six times higher than pristine graphitic carbon nitride (U). The apparent quantum yield (AQY) was measured to be 4.01 %, 4.89 %, and 3.72 % at 400 nm, 420 nm, and 450 nm, respectively, in the presence of potassium hydrogen phosphate (KPH). This enhanced performance is attributed to increased visible light absorption from the n-π∗ transition introduced by the thiophene ring and enhanced charge separation due to the donor-acceptor (DA) structure, with DB-2 acting as an electron donor. Prepared photocatalysts were characterized by XRD, XPS, FTIR, SEM, TEM, BET, ESR, EIS, Mott-Schottky, DRS, PL, and TRPL measurement. This study provides a simple and effective strategy to improve carbon nitride performance and underscores the importance of functional group positioning and structural isomers in molecular design for solar-energy applications.

Synthesis, characterization and anti-corrosion property of graphitic carbon nitride for carbon steel in acid medium

The present study involved the synthesis of a 2D material known as graphitic carbon nitride (g-C3N4) using solvothermal method and characterized using Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Gravimetric and electrochemical methods, including electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), electrochemical frequency modulation (EFM), and potentiodynamic polarization (PDP), in combination with surface analysis techniques such as SEM, EDS, optical profilometry (OP), and atomic force microscopy (AFM) are used to confirm its anti-corrosive properties. The findings revealed that the effectiveness of g-C3N4 increased proportionally with higher concentrations, reaching its peak potency of 85.0 % at a concentration of 100 ppm. Remarkably, the effectiveness of inhibition increased as the temperature rose until it reached 40 °C, but then decreased as the temperature continued to increase up to 60 °C. Density function theory and molecular dynamic simulation were used to correlate the experimental data to explain the intrinsic properties of g-C3N4 and the adsorption mechanism. The primary mechanism of corrosion inhibition was found to be the adsorption of g-C3N4 onto the steel surface. This was confirmed through surface analysis using SEM, EDS, AFM, OP and computational study.

Direct Surface Sulfidation of Layered Metal Hydroxides Using Bis(trimethylsilyl) Sulfide

Layered transition metal hydroxides have been extensively researched for applications such as electrodes and electrocatalysts owing to their tunable redox properties based on various cation compositions. To control critical physical properties such as chemical adsorption and conductivity in these applications, topochemical control of anion compositions will be effective. While many reports have demonstrated the synthesis of nitrides and sulfides by reacting layered metal hydroxides with different anion sources, the existing methods often result in the formation of microcrystalline aggregates.1 Even under mild conditions, core-shell structures are formed through dissolution and reprecipitation.2 Hence, it is necessary to develop a new approach that allows direct reaction of anionic species with metal species in the crystal framework. In this study, we propose a reaction using bis(trimethylsilyl) sulfide ((Me3Si)2S), commonly used for preparation of metal sulfide nanoparticles,3 as a sulfur source for the direct sulfidation of layered metal hydroxides.Layered nickel hydroxide nanocrystals (Ni(OH)2nc) were reacted in a liquid phase with a desired amount of (Me3Si)2S. The product is denoted as S_Ni(OH)2nc. X-ray diffraction (XRD) patterns of S_Ni(OH)2nc shows that all peaks corresponded to β-Ni(OH)2, and no new peaks appeared. The original Ni(OH)2nc was an aggregate of hexagonal plate-shaped nanocrystals with sizes of 80 to 200 nm and thicknesses of 15 to 25 nm, and no significant changes in crystal morphology after the reaction were observed after the reaction. In contrast to the blue-green color of Ni(OH)2nc, S_Ni(OH)2nc was obtained as a blue-gray powder. X-ray photoelectron spectroscopy (XPS) spectra of S_Ni(OH)2nc revealed new photoelectron peaks attributed to S2p, which were within the range of sulfide compounds. Scanning transmission electron microscopy with energy dispersive X-ray spectroscopy (STEM-EDS) mapping detected sulfur species at locations corresponding to plate-like crystals. Furthermore, quantitative analysis by EDS estimated the atomic ratio of sulfur to nickel in S_Ni(OH)2nc to be 5.0%, which corresponded well to the proportion of anion sites on the outer surface of Ni(OH)2nc. These results suggest that (Me3Si)2S reacts with Ni on the outer crystal surface of Ni(OH)2nc to form nickel sulfide compounds. Thus, sulfidation of layered metal hydroxides by (Me3Si)2S is effective in controlling the anion composition on crystal surfaces.(1) Y. Guo, T. Park, J.W. Yi, J. Henzie, J. Kim, Z. Wang, B. Jiang, Y. Bando, Y. Sugahara, J. Tang, and Y. Yamauchi, Adv. Mater., 2019, 31, 1807134. (2) B. Wang, C. Tang, H.-F. Wang, X. Chen, R. Cao, Q. Zhang, Adv. Mater., 2019, 31, 1805658. (3) R. García-Rodríguez, M. P. Hendricks, B. M. Cossairt, H. Liu, and J. S. Owen, Chem. Mater., 2013, 25,1233.

Tunable Absorption and Photochromism in Polyheptazine Imides Via a Solvent Mediated Synthetic Pathway

Layered, two dimensional metal containing polyheptazine imides (M-PHI) offer a complex playground for structure variation resulting in fascinating optoelectronic properties for several energy conversation and storage applications and beyond.1,2,3 Ionothermal or high temperature synthesis using both bottom-up molecular precursor routes and top-down approaches from melon have been used to synthesize M-PHI.4,5 A pressing problem for M-PHIs and infact for most polymeric carbon nitrides (PCN) is their insufficient visible light absorption arising from their symmetry forbidden n-π* electronic transition and fast charge recombination.4 Varying precursor ratios during thermal condensation of urea and oxamide, low pressure-high temperature melamine polymerization, urea pyrolysis, salt-melt synthesis using amino tetrazoles and many other methods have been successfully applied to synthesize red carbon nitrides with extended vis-absorption. These methods are majorly cumbersome and since each synthetic pathway is unique to one final material, structural relations between red carbon nitrides vs. their poor light-absorbing counterparts does not exist.7 In this work, we show the first solvent mediated route for red carbon nitride synthesis by a post-synthetic modification of yellow K-PHI via polymeric self-assembly. A competition between the solvent mediator bulkiness and its basicity, reaction temperature and time is shown to tailor KPHI absorption spectra, according to need. A combination of solid-state NMR, p-XRD, thermogravimetric analysis, with ground and excited state photophysical characterizations offer structural insights into red PHI. Variation in the long-ranged stacking order and pore content seem to have an impact on light absorption but does not limit their charge storage behavior as seen from electron paramagnetic resonance data upon illumination and time-delayed H2 production from water-splitting, experiments. In fact, this spectrally modified red PHI acts as a photochromic switch by a complete disappearance of the n-π* electronic transition during the formation of a stable photo-reduced state.