Mixture Of Melamine Research Articles

Up-cycling of waste paper for increased photo-catalytic hydrogen generation of graphitic carbon nitride under visible light exposure

BackgroundUp-cycling of waste papers to value-added carbon products has significant environmental and economic benefits in real life. This work aims to recycle the waste papers to construct amorphous carbon modified graphitic carbon nitride composite photocatalysts for efficient photocatalytic hydrogen generation from water under visible light. MethodsAmorphous carbon (labeled as a-C) was yielded from the office waste papers by simple sulphuric-acid treatment and then combined with graphitic carbon nitride (g-CN) to form the g-CN/a-C composite photocatalysts by the thermolysis of a-C and melamine mixture. Significant FindingsThe addition of a-C enlarges the surface area of g-CN from 11.52 m2 g−1 of pristine g-CN to 28.12 m2 g−1 of g-CN/a-C-100. In addition, the a-C incorporation can significantly separate the electrons from the photoexcited g-CN owing to the excellent conductivity of a-C. As a result, an increased photocatalytic H2 generation was realized under visible light exposure. The g-CN/a-C-100 sample with optimized a-C contents offers the highest photocatalytic H2 generation rate of up to 17.1 μmol h−1, which is ∼12 times higher than that of pristine g-CN under the same condition. The present study manifests the great potential of the recycling of office waste papers for increased photocatalytic H2 generation.

Visible light activation of photocatalysts formed from the heterojunction of sludge-generated TiO2 and g-CN towards NO removal

The feasibility of preparing TiO2/g-CN heterojunction from Ti-incorporated dried dye wastewater sludge is explored in this study. Two reaction routes of composite formation were evaluated. In the initial approach, one-step calcination of dried sludge and melamine mixture @600 °C was carried out. Detailed morphological and chemical characterizations showed that the one-step calcination route did not create TiO2/g-CN composites; instead, only N-doped anatase TiO2 composites were formed. Moreover, due to the non-uniform composition of organic content in the dried sludge, it was not easy to control the N doping level by varying melamine content (0–100%) in the precursor mix. However, successful formation of anatase TiO2 and g-CN was observed when a two-step calcination route was followed, i.e., via synthesis of anatase TiO2 from dried sludge, and later development of heterojunction by calcining (@550 °C) the TiO2 and melamine mixture. X-ray diffraction along with infrared and X-ray photoelectron spectroscopy verified the effective heterojunction. In addition, maximum atmospheric NO removal under UV and visible light were observed for the prepared composite when the melamine content in the precursor mixture was 70%. After 1 h of UV and visible light irradiation, the best TiO2/g-CN composite removed 25.71% and 13.50% of NO, respectively. Optical characterization suggested that the enhanced NO oxidation under UV/visible light was due to the bandgap narrowing and diminished photogenerated electron-hole recombination.

Facile fabrication of cobalt/nitrogen-doped graphite composites with high-performance microwave absorption

Magnetic metals are vital microwave-absorbing materials in alleviating electromagnetic (EM) pollution; however, in practical applications they are limited by their high density and relatively narrow absorption band. An effective strategy for addressing this issue is compounding magnetic metals with carbon materials. In this work, we fabricated the carbon/nitrogen-doped graphite (Co/NC) composites using a simple and low-cost method by directly calcining a dry mixture of melamine and Co powders in Ar gas. Part of Co/NC composite was calcined at 800 °C (Co/NC−800). The effects of variations in phase composition and morphology on the EM parameters and microwave-absorbing performance were investigated. Compared to pure Co, Co/NC−800 composite exhibits excellent microwave-absorbing performance such as strong absorption, better EM wave attenuation, and a lighter weight. Particularly, Co/NC−800 composite achieved the minimum reflection loss (RL) of −57.76 dB at 4.88 GHz and an effective absorption bandwidth (EABW, RL ≤ −10 dB) of 14.26 GHz (3.74–18.00 GHz) at a coating thickness d of 1.00–5.00 mm. Further, the maximum EABW of 5.50 GHz was attained at d = 1.86 mm. The optimal impedance matching, multiple scattering and reflections of EM waves on rough surfaces, and strong dielectric loss including conduction loss, interfacial and dipolar polarizations were noted as the main factors for the enhanced EM energy absorbance of Co/NC−800 composite. We believe our work may serve as a guideline for the fabrication of other light carbon-based magnetic metal composites as EM wave absorbers.

Na-Doped Graphitic Carbon Nitride for Removal of Aqueous Contaminants via Adsorption and Photodegradation

Graphitic carbon nitride (g-CN) has gained significant popularity as a visible-light-activated photocatalyst in energy and environmental applications. Most papers are dedicated to improving its photocatalytic performance; however, an investigation of its adsorption performance not only expands its application scope but also provides insight into its surface interactions. Herein, sodium-doped g-CN (Na(x)-CN) is synthesized via one-step pyrolysis of the mixture of melamine and sodium carbonate (Na2CO3). The prepared Na(x)-CN not only demonstrates superior adsorption capacities (maximum adsorption capacity of methylene blue up to 1319 mg/g, which is ∼650 times higher than that of the pristine g-CN) but also overcomes the lack of selectivity and slow adsorption kinetics of commonly used adsorbents. The extraordinary adsorption capacities are mainly attributed to π–π interactions and electrostatic interactions. Moreover, the Na2CO3-assisted synthesis route improved the optical properties and photocarrier separation efficiency, which are beneficial for further removal of contaminants via photodegradation. This work introduces a facile route for mass production of Na-doped g-CN with excellent adsorption capacities and selectivity as well as enhanced photocatalytic performance.

Facile one-pot synthesis of hierarchical N-doped porous carbon for efficient ibuprofen removal

Developing high-performance materials for the efficient removal of pharmaceutical contaminants from polluted water has gained tremendous attention but is still a huge challenge. Herein, various N-doped porous carbons (NPCs) were fabricated via a facile and solvent-free pyrolysis strategy by using a mixture of melamine, hexamethylenetetramine, Pluronic F 127, and ZnCl2 as precursor. The resulting NPCs featuring large specific surface areas (803–1002 m2/g) and high nitrogen content (3.79–5.24%) were used as efficient adsorbent for the capture of ibuprofen (IBP) from water. Due to the combination of abundant mesoporous and microporous structure as well as high nitrogen content, the adsorption equilibrium was achieved within 60 min and the adsorption capacity was calculated to be 113 mg/g. Furthermore, it was found that the adsorption capacity exhibited a good correlation with the nitrogen content. In addition, the adsorption capacity of the resulting NPC was well-maintained even after 4 cycles due to its superior stability. The study is expected to encourage the rational design and synthesis of versatile heteroatom-doped porous carbons for practical application in the field of environmental remediation.

Self-supporting Atmosphere-Assisted Synthesis of 1D Mo2 C-based Catalyst for Efficient Hydrogen Evolution.

One-dimensional materials exhibit fascinating properties in electrocatalytic applications but their fabrication faces the challenge of tedious and complicated operations. We have developed a bottom-up strategy to construct a 1D metal carbide catalyst (Mo2 C@NC) consisting of ultrafine Mo2 C nanoparticles embedded within nitrogen-doped carbon layers by simply calcining a mixture of ammonium molybdate, urea and melamine. Experimental results and thermodynamic calculations demonstrate that the retainable pyrolysis-generated self-supporting atmosphere plays a crucial role in the crystalline phase and morphology of materials. When functioned as an electrocatalyst for the hydrogen evolution reaction (HER), the achieved Mo2 C@NC presents an excellent catalytic activity as well as outstanding stability. This work could shed fresh light onto the facile synthesis of effective HER catalysts with 1D nanostructure.

Highly surface active niobium doped g-C3N4/g-C3N4 heterojunction interface towards superior photocatalytic and selective ammonia response

200 Nb-doped urea mixed melamine derived g-C3N4 (200Nb-UMCN) nanosheets were firstly synthesized from a mixture of urea, melamine, and niobium chloride at 550 °C for 3 h by pyrolysis. The crystalline phase, optical properties and morphological studies of series xNb-UMCN (x-100–300) materials were carried out by various characterization techniques, such as XRD, UV–Vis DRS, FTIR, FESEM, TEM, XPS, PL, BET, and photocurrent test. The results determined that Nb doping remarkably increased the photocatalytic and gas sensing life of urea-melamine derived g-C3N4, and the 200Nb-UMCN nanosheets reveal the highest photocatalytic and gas sensing performance with a 96% degradation rate of methylene blue (MB), 321 μmole h−1 hydrogen production through water decomposition, 76% of ammonia gas sensing compare with melamine derived g-C3N4(MCN). The 200Nb-UMCN half curled worm-like nanosheets reveal good structural stability under repeated application process. The effect of Nb and the half-curled worm-like structure led to various properties such as specific surface area, bandgap tailoring, embellished visible light-harvesting system, effective electron-hole separation, and tunable electronic configurations.

Multiple-heteroatom doped porous carbons from self-activation of lignosulfonate with melamine for high performance supercapacitors

A facile synthesis strategy by combination self-activation of biomass materials with heteroatom dopant in one-step is developed to fabricate porous carbons (NO-PCMs) doping with N, O, and S elements from direct carbonization of sodium lignosulfonate and melamine mixture. Two different types of active defects are constructed simultaneously through the decomposition of sodium lignosulfonate in NO-PCMs, exhibiting hierarchical porosity and abundant heteroatoms contents. The typical NO-PCMs displayed high specific capacitance (300 F g−1 at 0.1 A g−1) and outstanding cycling stability (99% capacitance retention after 10,000 charge/discharge cycles at 10 A g−1) in 6 M KOH electrolyte. Furthermore, the assembled symmetric supercapacitors exhibited high specific capacitance of 162 F g−1 at 20 A g−1, 71% capacitance retention at current density up to 20 A g−1, and possessed high specific energy density of 21.6 Wh kg−1 with an excellent power density of 92 W kg−1 operated in the wide voltage range of 1.8 V in 1 M Na2SO4 aqueous electrolyte, demonstrating the broad prospects of biomass/biowaste being used to prepare electrode materials.

Rapid Microwave Synthesis of Mesoporous Oxygen-Doped g-C3N4with Carbon Vacancies for Efficient Photocatalytic H2O2Production

Oxygen-doped g-C₃N₄ (CN) with carbon vacancies (O–CNC) was synthesized by microwave heating the mixture of melamine–cyanuric acid (MCA) supramolecular aggregates and oxalic acid for only 7 min. The as-synthesized O–CNC shows a mesoporous structure and exhibits a tunable band structure, optimized charge separation, and significantly enhanced two-electron reduction for H₂O₂ production. The photocatalytic H₂O₂ production rate reaches 2008.4 μmol h–¹ g–¹ under simulated sunlight irradiation, which is more than 4 times higher than that of pristine bulk CN. The enhanced photocatalytic performance is attributed to the synergistic effects of the mesoporous structure with a large specific surface area, doped oxygen atoms, and carbon vacancies. These results have provided a facile and efficient way for realizing the practical application of CN in photocatalytic H₂O₂ production.

Doping of graphitic carbon nitride with oxygen by means of cyanuric acid: Properties and photocatalytic applications

Bare and oxygen doped graphitic carbon nitride were synthetized by the thermal polymerization of melamine (CN-M) and the mechanical mixtures of melamine and cyanuric acid, respectively, at 550 °C for 4 h. The ratios of melamine and cyanuric acid were 1:0.5, 1:1 and 1:2 (CN-MCA1, CN-MCA2 and CN-MCA3). The content of oxygen increased from 1.88 wt% (CN-M) to 3.93 wt% (CN-MCA3) and the specific surface area increased from 14 to 41 m2 g−1. The prepared CN materials were characterized by the elemental analysis, UV-Vis diffuse reflectance, X-ray diffraction, Fourier transform infrared spectrometry, the physisorption of nitrogen, scanning electron and high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, the determination of zeta potentials, and the Mott-Schottky method.The addition of cyanuric acid led to partial changes in the CN morphology, as documented by occurrence of CN tubes, increase in the specific surface area and was a source of additional -O- and -OH moieties which modified the CN surface in addition to the spontaneous oxygenation observed in CN-M. The above effects positively influenced photocatalytic activity of the CN materials as demonstrated using Rhodamine B (RhB) and the Ofloxacin antibiotics. The photocatalytic decomposition of Ofloxacin was more efficient than that of RhB and differed in kinetics (first-order vs. zero-order reaction). The reusability and stability of the CN materials was verified by repeating batch photocatalytic decompositions of Ofloxacin experiments for five times.

Conjugated polymer coated MIL-125(Ti) as an efficient photocatalyst for selective oxidation of benzylic C[sbnd]H bond under visible light

Selective oxidation of saturated CH bonds to value-added chemicals under mild conditions is of great importance in chemical community. In this work, conjugated polymer (PMPTA) coated MIL-125(Ti) composites with type I heterojunction structure were obtained from the mixture of MIL-125(Ti), melamine and terephthalaldehyde via a solvent-free hydrothermal method. The MP-30 with optimal composition has excellent photocatalytic activity for the selective oxidation of benzylic CH bonds to their corresponding aldehydes and ketones under the illumination of 420 nm light using O2 as oxidant and N-Hydroxyphthalimide (NHPI) as co-catalyst. The conversions of fluorene catalyzed by MIL-125(Ti) and PMTPA are 32% and 65%, respectively, while the conversions of fluorene over MP-20, MP-30 and MP-40 are significantly improved, which are 86%, 99% and 77%, respectively. The characterization results from photoluminescence spectroscopy, photocurrent and band gap positions demonstrate that the one-way transfer of electrons and holes between the MIL-125(Ti) and PMTPA through the heterojunction structure allows the substrate to react rapidly on the outer layer of heterostructured MIL-125(Ti)/PMTPA, resulting an increase in photocatalytic efficiency. Moreover, the introduced heterojunction structure reduces the recombination of photo-generated electrons and holes and improves the efficiency of the conversion of holes into reaction intermediates.

Mixture of Graphene Oxide/Phosphoric Acid/Melamine as Coating for Improved Fire Protective Performance and Enhancement of Surface Electrical Properties on Wood Chipboard.

Looking for multifunctional materials, an assessment of the performances both as fire retardant and generator of electrically conductive surfaces for a three component mixture of graphene oxide, phosphoric acid and melamine applied on wood chipboard was performed. A simple approach was used to investigate the intumescent char formation and quantify the loss mass during vertical burning tests, in which the prepared samples were exposed for a certain time interval to a flame generated by an ethanol lamp in ambient conditions. Moreover, mass loss evolution and structural changes that occur during the burning process were more comprehensive investigated by differential thermal and thermogravimetric (DTA/TGA) techniques. By comparing the performances between the wood chipboard samples without any coverage and those covered with one or multiple component mixture, an increase of protection against the fire action was noticed when the three component mixture was used. Also, an improvement of the electrical properties was observed, after flame exposure of the samples covered with multiple layers (i.e., two and three), when the three component mixture was used. Morphological and structural investigations by microscopy (optical and electronic-SEMEDX), X-ray diffraction (XRD) and spectral (Raman, FTIR) methods are described. An assessment of market potential is also discussed.

Boosting the Catalytic Performance by Confining Rich Carbon Atoms over Graphite Carbon Nitride Structure

In this study, the porous ultrathin graphitic carbon nitride (CN) nanosheets with rich C and nitrogen defects were prepared by one-step calcining the mixture of melamine and glucose (Glu) in air atmosphere (Glu-CN). Introducing simultaneously rich C atoms and nitrogen defects into CN structures continuously modulates the bandgaps from 2.67 to 1.81 eV of CN photocatalysts. Due to large surface area, more active sites, remarkably longer lifetime of charge carriers and adjustable band gap structure, the prepared ultrathin porous CN nanosheets show the enhanced photocatalytic performance for the degradation of methyl orange (MO) under visible light. The degradation efficiency of optimal CN nanosheet photocatalyst for MO is 5.75 times that of bulk CN. This work provides a facile and universal relevance approach to engineer the band structures of CN by introduction of rich C and porous morphology for high-performance photocatalytic, which can provide informative principles for the design of efficient photocatalysis systems for solar energy conversion.

On P-doping of graphitic carbon nitride with hexachlorotriphosphazene as a source of phosphorus

The synthesis of P-doped graphitic carbon nitride (PCN) by in situ doping via co-pyrolysis of melamine and hexachlorocyclotriphosphazene (HCCP) is being investigated. The amount of HCCP varies between 2 and 40 wt% and the results show continuous enrichment of graphitic carbon nitride (CN) by phosphorus. The detailed characterization of prepared samples leads to the proposition of the occurrence of phosphorus in synthesized samples as well as to the proposition of a P-doping mechanism. The results of the characterization techniques used indicate that with up to 1.2 wt% of phosphorus in final PCN, phosphorus predominantly substitutes carbon in the structure. An increase of the phosphorus content to 2.44 wt% causes its incorporation into substitutional positions and part of the phosphorus occurs in other forms. PCN with 2.44 wt% of phosphorus obtained from the mixture of melamine with 20 wt% of HCCP thermally treated at 525 °C shows the highest photodegradation activity under VIS irradiation.

A robust bifunctional electrocatalyst for rechargeable zinc-air batteries: NiFe nanoparticles encapsulated in nitrogen-doped carbon nanotubes

Developing high-efficiency, low-cost, and stable bifunctional oxygen electrocatalysts is essential for the commercialization of rechargeable metal-air batteries. Herein, three-dimensional self-assembled microspheres via in situ encapsulation of NiFe alloy nanoparticles (NPs) into N-doping carbon nanotubes (NiFe@NCNTs) have been achieved through pyrolyzing a mixture of nickel-iron alkoxide and melamine. The as-prepared electrocatalyst exhibits outstanding oxygen reduction reaction (ORR) performance with a half-wave potential of 0.79 V and oxygen evolution reaction (OER) activity with a low overpotential of 330 mV at 10 mA cm−2. The eminent activity of NiFe@NCNTs is ascribed to high dispersion of active sites (zero-dimensional core-shell structure of NiFe@NC) and one-dimensional conductive network (NCNTs). Accordingly, the zinc-air battery assembled with NiFe@NCNTs as the air cathode exhibits a long cycling life of 200 h with a high energy efficiency of 65.6%. This work may shed new light on the design of advanced bifunctional electrocatalysts toward metal-air batteries.

The pathologic lesions of liver caused by melamine alone or in combination with cyanuric acid in mice

The toxicity of melamine (MA) and its analogue cyanuric acid (CA) in multiple organs has been widely investigated. The purpose of this study was to characterize the pathological lesions of the liver caused by melamine alone or in combination with CA. Mice were oral administered 0, 25, 50, or 100 mg/kg/day MA and CA mixture (MC), or 25, 50, and 100 mg/kg/day MA alone for 7 days. We found MC caused increase of liver weight index and elevations of the serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine (Cr). Histopathologically, both MA and MC caused scattered necrosis and inflammation cell infiltration in liver. Notably, at 100 mg/kg/day MC, melamine-related crystals were observed in hepatic sinusoid. The liver at high-dose MA and MC groups were further examined by TEM. There were marked degeneration of the mitochondria, and crystal deposition in the Disse space or cytoplasm of hepatic cells and Kupffer cells. TUNEL staining revealed that MA and MC caused apoptosis of hepatocytes and Kupffer cells. Western blotting showed the expression of Bcl-2 decreased, and Bax and caspase-3 increase in liver. The analysis of oxidative stress showed that the expression and activities of two key antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) decreased, and the concentration of malondialdehyde (MDA) elevated in MA- and MC-treated mice. These results from this study demonstrated that both MA and MC caused pathological damage to the liver in mice, especially when ingested in high concentration.

Effect of particle size of vermiculite on the microstructure and photocatalytic performance of g-C3N4/vermiculite composite

g-C3N4/vermiculite composites were synthesized by calcining the wet-mixed mixture of melamine and pre-expanded vermiculite, which pre-heated from different particle size of vermiculite (30–60, 60–100, 100–200 and 200 mesh). Pre-heating destroyed the crystal structure of vermiculite and enlarged its interlayer space, which was beneficial to the synthesis of g-C3N4 nano-sheets or nano-particles. With the decrease of the particle size of vermiculite, the dispersity of vermiculite and g-C3N4 in g-C3N4/vermiculite composite improved and the specific surface area of the composites increased gradually, but the agglomeration of g-C3N4 enhanced a little due to the lowered expanding degree of vermiculite. The photocatalytic performance of the g-C3N4/vermiculite composite enhanced firstly, and then dropped down as vermiculite particles were smaller than 100 mesh. g-C3N4/vermiculite composite synthesized from vermiculite of 60–100 mesh exhibited the optimum photocatalytic activity. It degraded 95.68% of Rhodamine B molecules in aqueous solution (100 mL, 10 mg/L) after photocatalysis for 90 min, and its reaction rate constant was about 2.7 times as large as that of the pure g-C3N4. The weakened agglomeration, the closely contacted interface between g-C3N4 and vermiculite, the enhanced separation efficiency of photo-generated carriers and the narrowed the band gap were responsible for the excellent photocatalytic performance of this g-C3N4/vermiculite composite.

Особенности измерения температурных зависимостей электрического сопротивления углеродных материалов, полученных термолизом смесей фенолфталеина с меламином

Carbon materials with high nitrogen content show great potential for modern electronics. To obtain such materials, it is convenient to use melamine as a source of nitrogen, since during its thermal decomposition a significant amount of nitrogen-containing groups is formed, which can be incorporated into the structure of the carbon material. The study of the temperature de-pendence of resistance for the obtained materials has made it possible to establish the effect of nitrogen atoms on the band structure of the samples. The article describes a method for obtaining single-phase nitrogen-containing solid solutions, based on amorphous carbon, by thermolysis of molten mixtures of melamine with phenolphthalein under heating to 500 °C. This method has made it possible to achieve the nitrogen content of 21 wt. %. The results of the study of new materials by the X-ray phase analysis are presented, confirming the chaotic structure of solid solutions and the absence of long-range order in the arrangement of carbon or nitrogen atoms. The morphology of the obtained samples with various concentrations of phenolphthalein varies from loosely bound powders to solid foam. The complexity of measuring the temperature dependences of resistivity is associated with the difficulty of preparing standard rectangular samples. To measure the temperature dependences of resistance, the samples were ground to a powder of the given granulometric composition, and a vacuum measuring cell was constructed, as well as measurement technique was developed in the range of 30–300 °C. The paper describes the experimental setup and sample preparation, and also presents the results of measurements of samples of solid solutions of nitrogen in amorphous carbon with a high nitrogen content. A monotonical decrease in the band gap of solid solutions from 1.07 to 0.61 eV with an increase in the nitrogen content in them has been shown.

Preparation of iron and nitrogen co-doped carbon material Fe/N-CCM-T for oxygen reduction reaction

In this paper, iron and nitrogen co-doped carbon material with nanotube structure (Fe/N-CCM-T) was synthesized by pyrolyzing a mixture of Fe salt, chitosan and melamine and displayed high electrocatalytic performance for oxygen reduction reaction (ORR). The structure of the Fe/N-CCM-T was characterized and their ORR performance in alkaline media was investigated by linear sweep voltammetry, cyclic voltammetry and chronoamperometry. Fe/N-CCM-T displayed better ORR performance than other carbon materials like Fe/N-CC-800. The Fe/N-CCM-800 with a large surface area (302.5 m2/g) especially exhibited the best ORR electrocatalytic performance among the prepared carbon materials, which was also proved by its similar Tafel slope (76 mV decade−1) to Pt/C catalyst (74 mV decade−1). Fe/N-CCM-800 showed similar ORR activity as commercial Pt/C catalyst, but superior tolerance to methanol and stability. Such high ORR performance of the Fe/N-CCM-T can be attributed to its nanotube structure, high specific surface area (SSA), high graphitic-N and pyridinic-N contents.

The effect of ammonium polyphosphate:melamine:pentaerythritol ratio on the efficiency of fire protection of reactive coatings

In order to optimize the formulation of fire protective coatings for metal constructions, the effect of the ratio of main components in an intumescent system "ammonium polyphosphate–melamine–pentaerythritol" on the thermal destruction of the coating under conditions of fire (200–8000C) has been investigated. Thermal transformations of coatings were studied both by thermogravimetry with stepwise determination of the expansion coefficient by temperature variation and by IR spectroscopy. It was established for the first time that the ratio of ammonium polyphosphate, melamine and pentaerythritol as well as their content in the intumescent system is a factor determining the limit of the fire resistance of steel constructions, which a fire protective coating can ensure. Intumescent coatings with an ammonium polyphosphate:melamine:pentaerythritol ratio of 2:1:1 were shown to be more effective ones to provide the fire resistance of a steel construction during 30 minutes (R30). In turn, the use of the above ratio of 3.5:1:1.5 can provide the limit of the fire resistance of steel construction during 60 minutes (R60). The mixture of melamine and dicyandiamide in the intumescent system causes a synergistic effect, which leads to a non-additive increase in the fire protective efficiency of the coating. The results of this study have been confirmed by full-scale fire tests; they may be used to develop effective means of fire protection of steel constructions.