Carbon Nitride Nanomaterials Research Articles

β-Cyclodextrin/Zn-Fe layered double hydroxides/graphitic carbon nitride nanomaterials based potentiometric sensor for paroxetine determination in environmental water samples.

Developing targeted and sensitive analytical techniques for drug monitoring in different specimens are of utmost importance. Herein, a first attempt was made for the determination of paroxetine (Prx+) in environmental water samples using a novel, sensitive, selective, stable, accurate and eco-friendly potentiometric sensor based on Zn-Fe layered double hydroxides/graphitic carbon nitride (Zn-Fe LDH/g-C3N4) nanomaterials with β-cyclodextrin (β-CD) as the sensing ionophore and dibutyl phthalate (DBP) as the plasticizer. The prepared nanomaterial was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The surface properties of the proposed sensor were characterized by electrochemical impedance spectroscopy (EIS). The sensor exhibited an excellent Nernstian slope of 59.3 ± 0.7 mV decade-1 covering a wide linear working range of 1.0 × 10-6 to 1.0 × 10-2 mol L-1, low detection limit of 3.0 × 10-7 mol L-1, low quantification limit of 9.9 × 10-7 mol L-1, long life time, sufficient selectivity, high chemical and thermal stability within a wide pH range of 2.0-9.0. This analytical method was successfully implemented for Prx+ determination in a pure form, pharmaceutical formulation and different water samples.

Highly Ordered C-Rich Carbon Nitride Nanomaterials with Pyrrole and Imidazole Moieties for Photocatalytic Overall Water Splitting through Built-In Electric Field

Highly Ordered C-Rich Carbon Nitride Nanomaterials with Pyrrole and Imidazole Moieties for Photocatalytic Overall Water Splitting through Built-In Electric Field

Enhanced biomimetic catalysis via self-cascade photocatalytic hydrogen peroxide production over modified carbon nitride nanozymes for total antioxidant capacity evaluation

The peroxidase mimics usually requires the addition of exogenous hydrogen peroxide (H2O2), which greatly hinder their practical applications. Herein, through rational co-modification of multiple elements (potassium (K), chlorine (Cl) and iodine (I)), the modified carbon nitride nanomaterials (KCl/KI-CN) could serve as efficient bifunctional catalysts. The multiple elements doping and the incorporation of cyano groups (CN) are deemed to enhance their photocatalytic and peroxidase-like activity, respectively. Based on the photocatalytic function, H2O2 can be produced continuously and steadily via two-electron oxygen reduction over modified carbon nitride under visible light irradiation. Subsequently, the KCl/KI-CN could catalyze the chromogenic substrate by the in-situ produced H2O2. Taking advantage of the bifunctional properties of modified carbon nitride, we for the first time demonstrate a self-cascade catalytic process and apply successfully for the ascorbic acid (AA) detection and versatile total antioxidant capacity (TAC) evaluation. This paper not only prepares an efficiently bifunctional catalyst but also provides a new self-cascade photocatalytic H2O2 production strategy for the peroxidase-like application.

Analysis of degradation effect of carbon nitride nanomaterials in pollutant treatment

Abstract Photocatalytic technology is known as a green technology in solving energy problems and pollution problems, which can generate clean energy and degrade pollutants. In order to study the degradation performance of carbon nitride and its composites on air pollutants and water pollutants, this paper constructs TiO2/g-C3N4 composite photocatalysts by compositing graphite-like phase carbon nitride (g-C3N4) with titanium dioxide (TiO2) using titanium tetrachloride and melamine as raw materials in a water bath method. The physicochemical properties of the prepared complexes were analytically characterized by X-ray diffraction, UV-Vis diffuse reflectance, and X-ray photoelectron spectroscopy, and their degradation activities were examined and compared. The results of all the tests showed that the prepared 5 wt% TiO2/g-C3N4 nanocomposites performed better compared to other mass percentages of nanomaterials. The degradation of pollutants also resulted in better photocatalytic performance of the 5 wt% nanomaterials, with catalytic efficiencies of 54.2% and 99.5% for NO and methylene blue, respectively, at 30 min, and the good photocatalytic activity remained after five cycles.

Application of Biomass‐Based Nanomaterials in Energy

The utilization of biomass as a sustainable and renewable resource for nanomaterial synthesis has received considerable attention in recent years. Through the efficient utilization of biomass waste, opportunities for energy production, energy conversion, and the fabrication of nanomaterials can be maximized. The combination of biomass‐based nanomaterials with additional nanomaterials makes the composite system have more remarkable performance, which further facilitates the transformation procedure of biomass‐based nanomaterials for applications. This comprehensive review provides an overview of the preparation and applications of biomass‐based nanomaterials. The preparation section covers a range of methods for synthesizing biomass‐based nanomaterials, including biomass‐based carbonaceous nanomaterials, biomass‐based carbon nitride nanomaterials, nanomaterials derived from biomass templates, biomass‐based nanomaterials as carriers, and the use of biomass for metal ion reduction. The applications section explores the diverse applications of biomass‐based nanomaterials, such as hydrogen production, carbon dioxide reduction, batteries, and supercapacitors. The unique properties and advantages of biomass‐based nanomaterials in each application are discussed. The conclusion summarizes the current progress and presents future perspectives for the development and utilization of biomass‐based nanomaterials. This review emphasizes the potential of biomass as a valuable and sustainable source for nanomaterial synthesis, opening up promising opportunities in various fields.

Graphitic carbon nitride nanomaterials for high‐performance supercapacitors

AbstractGraphitic carbon nitride is a promising material as an electrode material for advanced electrochemical energy storage devices because of its controllable structure, physicochemical properties, and abundant active sites. However, its intrinsic properties as electrode materials can not be fully expressed owing to limited electrical properties, which impede charge transfer and material exchange inside devices. During the past decade, the challenge has been addressed through material engineering strategies, such as exfoliation and composition, and then advanced energy devices, such as supercapacitors, have been assembled. In this regard, a timely review of graphitic carbon nitride for high‐performance supercapacitors requires to be put forward for summarizing past studies and inspiring future research works as well. This review article summarizes recent progress in material synthesis and property regulation of graphitic carbon nitride nanomaterials and their application in assembling advanced supercapacitors with high energy density and superior working stability. Finally, based on existing research and our experimental experience, a perspective for directing future research has been presented concerning material synthesis and electrochemical application of graphitic carbon nitride.

Single-Step Synthesis of Graphitic Carbon Nitride Nanomaterials by Directly Calcining the Mixture of Urea and Thiourea: Application for Rhodamine B (RhB) Dye Degradation

Recently, polymeric graphitic carbon nitride (g-C3N4) has been explored as a potential catalytic material for the removal of organic pollutants in wastewater. In this work, graphitic carbon nitride (g-C3N4) photocatalysts were synthesized using mixtures of low-cost, environment-friendly urea and thiourea as precursors by varying calcination temperatures ranging from 500 to 650 °C for 3 h in an air medium. Different analytical methods were used to characterize prepared g-C3N4 samples. The effects of different calcination temperatures on the structural, morphological, optical, and physiochemical properties of g-C3N4 photocatalysts were investigated. The results showed that rhodamine B (RhB) dye removal efficiency of g-C3N4 prepared at a calcination temperature of 600 °C exhibited 94.83% within 180 min visible LED light irradiation. Photocatalytic activity of g-C3N4 was enhanced by calcination at higher temperatures, possibly by increasing crystallinity that ameliorated the separation of photoinduced charge carriers. Thus, controlling the type of precursors and calcination temperatures has a great impact on the photocatalytic performance of g-C3N4 towards the photodegradation of RhB dye. This investigation provides useful information about the synthesis of novel polymeric g-C3N4 photocatalysts using a mixture of two different environmentally benign precursors at high calcination temperatures for the photodegradation of organic pollutants.

Electrochemiluminescence bioassays based on carbon nitride nanomaterials and 2D transition metal carbides

Electrochemiluminescence (ECL) is a powerful technique for bioassays. To meet the growing demand for bioassays, it is necessary to develop new ECL emitters and co-reaction acceleration strategies to improve detection sensitivity and expand the application scope. Carbon nitride nanomaterials and 2D transition metal carbides, as newly emerging carbon-based nanomaterials, have been increasingly used for ECL bioassays due to their attractive optical and electrochemical properties as well as diversity. In this minireview, we summarized the latest advances in ECL bioassays using carbon nitride nanomaterials and 2D transition metal carbides in the past two years. Finally, we briefly discuss the future trends and challenges of carbon-based nanomaterials for ECL bioanalysis.

Carbon Nitride Nanomaterials: Properties, Synthetic Approaches and New Insights in Fluorescence Spectrometry for Assaying of Metal Ions, Organic and Biomolecules

AbstractRecent years, carbon nitride (C3N4) nanomaterials have engraved new insights into fluorescence spectrometry for the analysis of wide variety analytes (metal ions, organic and biomolecules). This review concentrates on the properties of C3N4 nanomaterials, synthetic routes for C3N4 nanomaterials and insights in fluorescence spectrometry for the detection of various chemical species. Firstly, this review summarizes the properties (photoluminescence, electrochemical, thermal and chemical stability) of C3N4 nanostructure materials. Secondly, the recent advances on the synthetic routes for the fabrication of C3N4 nanostructures including top‐down (hydrothermal, solvothermal and exfoliation) and bottom‐up (hard and soft templet, template‐free, solvothermal, hydrothermal and microwave) are discussed. Thirdly, we describe the new insights of C3N4 nanostructures as probes for assaying of metal ions, organic and biomolecules from complex samples via fluorescence spectrometry. Finally, we have summarized the future perspectives of carbon nitride nanostructures in analytical chemistry are described.

Implementation of graphitic carbon nitride nanomaterials and laser irradiation for increasing bioethanol production from potato processing wastes.

Agricultural and agro-industrial wastes (e.g., potato peel waste) are causing severe environmental problems. The processes of pretreatment, saccharification, and fermentation are the major obstacles in bioethanol production from wastes and must be overcome by efficient novel techniques. The effect of exposing the fungi (yeast) Saccharomyces cerevisiae to laser source with the addition of graphitic carbon nitride nanosheets (g-C3N4) with different concentrations on bioethanol production was investigated through the implementation of a batch anaerobic system and using potato peel waste (PPW). Dichromate test was implemented as quantitative analysis for quantification of the bioethanol yield. The benefits of this test were the appearance of green color indicating the identification of ethanol (C2H5OH) by bare eye and the ease to calculate the bioethanol yield through UV-visible spectrophotometry. The control sample (0.0ppm of g-C3N4) showed only a 4% yield of bioethanol; however, by adding 150ppm to PPW medium, 22.61% of ethanol was produced. Besides, laser irradiations (blue and red) as influencing parameters were studied with and without the addition of g-C3N4 nanomaterials aiming to increase the bioethanol. It was determined that the laser irradiation can trigger the bioethanol production (in case of red: 13.13% and in case of blue: 16.14% yields, respectively) compared to the control sample (in absence of g-C3N4). However, by adding different concentrations of g-C3N4 nanomaterials from 5 to 150ppm, the bioethanol yield was increased as follows: in case of red: 56.11% and, in case of blue: 56.77%, respectively. It was found that using fungi and exposing it to the blue laser diode source having a wavelength of 450nm and a power of 250 mW for a duration of 30min with the addition of 150mg L-1 of g-C3N4 nanomaterials delivered the highest bioethanol yield from PPW.

Photoinduced Self‐Assembly of Carbon Nitride Quantum Dots

AbstractThe study of nanocrystal self‐assembly into superlattices or superstructures is of great significance in nanoscience. Carbon nitride quantum dots (CNQDs), being a promising new group of nanomaterials, however, have hardly been explored in their self‐organizing behavior. Here we report of a unique irradiation‐triggered self‐assembly and recrystallization phenomenon of crystalline CNQDs (c‐CNQDs) terminated by abundant oxygen‐containing groups. Unlike the conventional self‐assembly of nanocrystals into ordered superstructures, the photoinduced self‐assembly of c‐CNQDs resembles a “click reaction” process of macromolecules, in which the activated ‐OH and ‐NH2 functional groups along the perimeters initiate cross‐linking of adjacent QDs through a photocatalytic effect. Our findings unveil fundamental physiochemical features of CNQDs and open up new possibilities of manipulating carbon nitride nanomaterials via controlled assembly. Prospects for potential applications are discussed as well.

Photoinduced Self-Assembly of Carbon Nitride Quantum Dots.

The study of nanocrystal self-assembly into superlattices or superstructures is of great significance in nanoscience. Carbon nitride quantum dots (CNQDs), being a promising new group of nanomaterials, however, have hardly been explored in their self-organizing behavior. Here we report of a unique irradiation-triggered self-assembly and recrystallization phenomenon of crystalline CNQDs (c-CNQDs) terminated by abundant oxygen-containing groups. Unlike the conventional self-assembly of nanocrystals into ordered superstructures, the photoinduced self-assembly of c-CNQDs resembles a "click reaction" process of macromolecules, in which the activated -OH and -NH2 functional groups along the perimeters initiate cross-linking of adjacent QDs through a photocatalytic effect. Our findings unveil fundamental physiochemical features of CNQDs and open up new possibilities of manipulating carbon nitride nanomaterials via controlled assembly. Prospects for potential applications are discussed as well.

Highly fluorescent g-C3N4 nanobelts derived from bulk g-C3N4 for NO2 gas sensing

The fluorescent emission wavelengths of nanostructures derived from bulk graphitic carbon nitride were commonly lower than those of their bulk due to the quantum confinement effect, which are disadvantageous for bioimaging and sensing applications. Herein, a new strategy to engineer graphitic carbon nitride nanomaterials with tunable fluorescent wavelength and intensity was proposed via thermal treatment of bulk graphitic carbon nitride at high temperature and then hydrolysis in alkali solution. Highly fluorescent g-C3N4 nanobelts with emission peak at 494 nm, 19 nm higher than that of bulk graphitic carbon nitride and 23.6% quantum yield were successfully obtained by controlling the heating temperature at 750 °C for 2 h and the hydrolysis in 4 mol L−1 NaOH solution for 8 h. Finally, a home-made portable gas sensor for reversibly sensing of toxic NO2 gas at room temperature was designed by utilizing graphitic carbon nitride nanobelts as the fluorescent nanoprobe, which can overcome the disadvantages of high operation temperature or the interference of humidity resulting from the common chemiresistive sensors.

Fabrication of highly sensitive anticancer drug sensor based on heterostructured ZnO-Co3O4 capped on carbon nitride nanomaterials

Flutamide (FLT) is a nonsteroidal and antiandrogen drug with an explicit anti-androgenic behavior. Due to this reason, they are employed to treat prostate cancer. Also, they are utilized to cure superfluous androgen echelons. In recent days, zeolitic-imidazolate frameworks (ZIF) based metal–organic frameworks (MOFs) have grasped more consideration in the synthesis and preparation of MOFs based nanocomposite. Similarly, electrochemical detection of anti-cancer drugs are much needed. Herein, we report a novel preparation of zinc oxide-cobalt oxide capped on carbon nitride nanocomposite using a hydrothermal assisted sonochemical synthesis for detecting anti-cancer drug flutamide (FLT). The as-prepared ZnO-Co3O4@C3N4 NC was physically characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, and transmission electron microscope. Then, an as-prepared sample was electrochemically analyzed to detect anti-cancer drug FLT. Electrochemical impedance spectroscopy (EIS) was studied, and the ZnO-Co3O4@C3N4 NC modified electrode has displayed a lower Rct value. ZnO-Co3O4@C3N4 NC modified electrode shows a respectable linear range (0.01–98.6 µM) with a low detection limit (0.00373 µM) and good sensitivity (5.331 μA.μM−1.cm−2) towards FLT detection by differential pulse voltammetry (DPV) technique. Similarly, the ZnO-Co3O4@C3N4 NC sensor exhibits good selectivity, repeatability, and reproducibility towards FLT. Also, for real sample analysis, biological samples like urine and blood serum were investigated, and the results show reasonable practicability.

Porous graphitic carbon nitride nanomaterials for water treatment

This review summarizes the application of porous g-C3N4 in water treatment and modification to enhance its catalytic performance, showing the potential of porous g-C3N4 for the actual treatment of water bodies.

Photopolymerization performed under dark conditions using long-stored electrons in carbon nitride.

In nature, the chemical energy and electrons stored in ATP and NADPH generated during irradiation can facilitate biochemical reactions under dark conditions. However, in artificial photoreaction systems, it is still very difficult to perform photoreactions under dark conditions due to the fact that the photogenerated charge pairs can recombine immediately upon ceasing the irradiation. Preventing the recombination of photogenerated charge pairs still constitutes a major challenge at present. Here, it is reported that functionalized carbon nitride nanomaterials having many heptazine rings with a positive charge distribution, which can tightly trap photogenerated electrons, efficiently prevent the recombination of photogenerated charges. These stored charges are exceedingly long-lived (up to months) and can drive photopolymerization without light irradiation, even after one month. The system introduced here demonstrates a new approach for storing light energy as long-lived radicals, enabling photoreactions under dark conditions.

Elucidating the structure of the graphitic carbon nitride nanomaterials via X-ray photoelectron spectroscopy and X-ray powder diffraction techniques.

By using the most popular method of thermal condensation of dicyandiamide in a semi-closed system, graphitic carbon nitrides (gCNs) were synthesized at 500, 550, and 600 °C. The resulting materials were comprehensively analyzed via X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD)techniques. We show that the use of routine analytical methods provides an insight into the structure of the carbon nitride materials. The analysis of geometric linear structures and fully condensed structure of polymeric carbon nitrides was performed and the ranges within which the contents of different nitrogen species (pyridine, amine, imine and quaternary nitrogen) can change were determined. This analysis, in combination with quantitative XPS studies, permits to state that the carbon nitride structure prepared by the thermal condensation of dicyandiamide is closer to the structure in which poly(aminoimino)heptazine subunits are linked into chains rather than the structure involving fully-condensed polyheptazine network. The XRD analysis proved that the 3D crystal structure of carbon nitride is described more correctly by the orthorhombic cell and space group P21212 applied to condensed chains of poly(aminoimino)heptazine (melon) and not by the hexagonal cell with the space group P6m2.

New nitrides: from high pressure–high temperature synthesis to layered nanomaterials and energy applications

We describe work carried out within our group to explore new transition metal and main group nitride phases synthesized using high pressure-high temperature techniques using X-ray diffraction and spectroscopy at synchrotron sources in the USA, UK and France to establish their structures and physical properties. Along with previously published data, we also highlight additional results that have not been presented elsewhere and that represent new areas for further exploration. We also describe new work being carried out to explore the properties of carbon nitride materials being developed for energy applications and the nature of few-layered carbon nitride nanomaterials with atomically ordered structures that form solutions in polar liquids via thermodynamically driven exfoliation. This article is part of the theme issue 'Fifty years of synchrotron science: achievements and opportunities'.

High-pressure behavior and Hirshfeld surface analysis of nitrogen-rich materials: triazido-s-triazine (TAT) and triazido-s-heptazine (TAH)

Triazido-s-triazine (TAT) and triazido-s-heptazine (TAH) are two kinds of effective nitrogen-rich precursors for carbon nitride nanomaterials and potential high-energy density materials. In this work, the high-pressure behavior (0–500 GPa) and Hirshfeld surface of crystalline TAT and TAH were studied in details to better compare and reveal their stabilities. Crystal and molecular structures of TAT and TAH largely changed with the increase in pressure. The distortion of rings happens at 171 GPa for TAT and 483 GPa for TAH. The azide/tetrazole (AZ/TZ) isomerization happens in crystalline TAT, and the tetrazole ring forms at 266 GPa for the first time, while this phenomenon has not been observed in crystalline TAH during the whole process. Hirshfeld surface analyses intuitively show that: (1) both compounds possess the planar conjugated molecular structures; (2) N…N nonbonding interactions contribute a lot to stabilize their crystal packings; and (3) TAH is much more resistant to high pressure and more stable than TAT. The systematic investigation gives a guidance to understand the physical and chemical behaviors of nitrogen-rich azidoheterocyclic materials.

Controllable synthesis of graphitic carbon nitride nanomaterials for solar energy conversion and environmental remediation: the road travelled and the way forward

This review discusses advances in the synthesis and design of g-C3N4-based nanomaterials and their various photocatalytic and photoredox applications.