Improved Method For Synthesis Research Articles

Glutathione-Mediated Synthesis of WO3 Nanostructures with Controllable Morphology/Phase for Energy Storage, Photoconductivity, and Photocatalytic Applications.

Developing an improved synthesis method that controls the morphology and crystal phase remains a substantial challenge. Herein, we report phase and morphology-controlled hydrothermal synthesis of tungsten oxides by varying acid concentration and utilizing glutathione (GSH) as a structural directing agent, together with the exploration of their applications in supercapacitors, photoconductivity, and photocatalysis. Orthorhombic hydrated tungsten oxide (WO3·0.33H2O) with nonuniform block and plate-like morphology was obtained at 3 M hydrochloric acid (HCl). In contrast, nonhydrated monoclinic tungsten oxide (WO3) with smaller rectangular blocks was obtained at 6 M HCl. Further, the addition of GSH results in an increase in the surface area of the materials along with a narrowing of the band gap. Moreover, it plays a pivotal role in regulating the morphology through oriented attachments, Ostwald ripening, and the self-assembly of WO3 nuclei. GHTO and GTO polymorphs showed pseudocapacitive behavior with the highest specific capacitances of 450 and 300 F g-1 at 0.5 A g-1, maintaining 94 and 92% retention stability, respectively, over 1000 cycles at 2 A g-1. Also, the synthesized materials displayed favorable photoconductivity under light irradiation, implying potential utilization in photovoltaic applications. Moreover, these materials exhibited remarkable photocatalytic performance in the degradation of methylene blue (MB) dye, establishing themselves as highly effective photocatalysts. Therefore, nanostructured tungsten oxide showcases its versatility, rendering it an appealing candidate for energy storage, photovoltaic systems, and photocatalysis.

Cd doped ZnO nano-rectangles and their correlation with properties

Nowadays, the size, shapes and morphologies of zinc oxide (ZnO) can be controlled in a fascinating way by improved synthesis methods and controlled nucleation and growth processes driven by varying the experimental conditions. Nanoscience holds a particular fascination with ZnO because of its properties, which vary based on shape and how they evolve across a wide range of applications. We report here the room temperature synthesis of rectangular shaped cadmium (Cd) doped ZnO nanostructures by a wet chemical route employing surface modifications with the surfactants polyvinyl pyrrolidone, polyvinyl alcohol and biotin. A simple and general mechanism for the formation of the Cd doped ZnO nano-rectangles is discussed. The crystallographic, morphological and optical properties of the prepared nanostructures are also studied in connection with the role of surfactants and dopant, and correlated with their shape.

Thiourea modulated supercapacitive behavior of reduced graphene oxide

In this report, we investigated the role of the concentration of nitrogen and sulfur containing thiourea in modulating the electrochemical properties of reduced Graphene Oxide (rGO) by controlling the percentage of heteroatoms on the rGO surface. The synthesis route involved the preparation of Graphene Oxide (GO) using an improved method of synthesis in an economical way by reducing the volume of concentrated acids used. Furthermore, GO is reduced by using different mass proportions of thiourea via a simple reflux method. Characterization of the rGO samples by Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDAX) and elemental analysis through CHNS analyzer exhibited successful doping and impact of nitrogen and sulfur atoms on the graphene framework. The comparative electrochemical performance from Cyclic Voltammograms (CV), Galvanostatic Charge Discharge (GCD) profiles and Electrochemical Impedance Spectroscopy (EIS) measurements on the various rGO samples revealed the superiority of 1:8rGO having 15.190 wt% of nitrogen and 26.849 wt% of sulfur and S/N ratio of 1.768, in delivering highest specific capacitance of 465.21 F·g−1 at 1 mV·s−1 scan rate with a remarkable cyclic stability exhibiting a capacitive retention of 119 % and offering lowest charge transfer resistance and diffusion resistance. The study also demonstrated detrimental effect of excess thiourea on electrochemical properties of rGO. This work suggests an effective and simple approach for optimizing the nitrogen and sulfur content in rGO to enhance its electronic properties using thiourea.

Key Experimental Considerations When Evaluating Functional Ionic Liquids for Combined Capture and Electrochemical Conversion of CO2.

Ionic liquids (ILs) are considered functional electrolytes for the electrocatalytic reduction of CO2 (ECO2R) due to their role in the double-layer structure formation and increased CO2 availability at the electrode surface, which reduces the voltage requirement. However, not all ILs are the same, considering the purity and degree of the functionality of the IL. Further, there are critical experimental factors that impact the evaluation of ILs for ECO2R including the reference electrode, working electrode construction, cosolvent selection, cell geometry, and whether the electrochemical cell is a single compartment or a divided cell. Here, we describe improved synthesis methods of imidazolium cyanopyrrolide IL for electrochemical studies in consideration of precursor composition and reaction time. We explored how IL with cosolvents (i.e. acetonitrile, dimethylformamide, dimethyl sulfoxide, propylene carbonate, and n-methyl-2-pyrrolidone) affects conductivity, CO2 mass transport, and ECO2R activation overpotential together with the effects of electrode materials (Sn, Ag, Au, and glassy carbon). Acetonitrile was found to be the best solvent for lowering the onset potential and increasing the catalytic current density for the production of CO owing to the enhanced ion mobility in combination with the silver electrode. Further, the ECO2R activity of molecular catalysts Ni(cyclam)Cl2 and iron tetraphenylsulfonato porphyrin (FeTPPS) on the carbon cloth electrode maintained high Faradaic efficiencies for CO in the presence of the IL. This study presents best practices for examining nontraditional multifunctional electrolytes amenable to integrated CO2 capture and conversion technologies for homogeneous and heterogeneous ECO2R.

Enhancing the thermal stability of nanostructured carbonaceous materials using an improved method of template synthesis

Enhancing the thermal stability of nanostructured carbonaceous materials using an improved method of template synthesis

Design and optimization of Ni–Fe–La based catalytic system for CO2 utilization for sustainable syngas production via dry reforming of methane

The present work aims to design a robust Ni–Fe–La catalyst for methane reforming with CO2. A series of catalysts with mesoporous pore structures were prepared using a modified constant pH co-precipitation approach. Taguchi's L16 design and multi-parameter response optimization approach provide a detailed interpretation and optimization of the catalyst composition. The control parameters for the optimization study include nickel as primary active (6–24 wt %), Fe as second metal (0–9 wt%), La2O2 as a promoter to the catalyst (0–24 wt%), and rest γ-alumina as catalyst support (52–94 wt%). Various analytical and chemical methods were used to characterize optimized catalyst recipes thoroughly. According to Study findings, the reforming catalyst quality, measured by reactant conversions, deactivation percentage, and H2/CO ratio, has dramatically increased since the basic testing. The dry reforming catalyst's sustainable activity was primarily driven by the Fe metal content (wt.%), followed by the Ni metal content and La2O3. In 100 h of time on stream study, the catalyst showed excellent stability with ∼90% CH4 conversion, and it was free of any coke deposition as well as severe metal sintering. The improved synthesis method resulted in a catalyst with good physicochemical features, promoting high activity and stability in dry reforming operations.

Photoluminescence Investigations and Band Gap Engineering in Environment Friendly ZnO Nanorods: Enhanced Water Treatment Application and Defect Model.

The inadvertent discharge of industrial effluents, mainly textile, contributes to the complex contamination load in water bodies. Textile dyes are the critical effluents and recalcitrant to traditional remediation procedures. Therefore, energy viable and environment friendly solutions are needed. In this study, we have synthesized zinc oxide nanorods (NRs) at various temperatures using modified thermal decomposition and evaluated its photocatalytic activities. Field effect scanning electron microscopy has confirmed rod-like morphology till TS = 500 °C and spherical morphology from TS = 600 °C onward. Photoluminescence spectra have shown a prominent defect peak in the synthesized ZnO, except for the NRs synthesized at 300 °C. Synthesized ZnO NRs and NPs have been employed to degrade crystal violet (CV) and congo red (CR) dyes. ZnO NRs have shown impressive photocatalytic performance with faster treatment time as compared to the earlier reports. Synthesis parameters are well correlated with the observed high efficiency and the band gap tailoring. Based on our findings, for the first time, we have proposed (i) defect model correlating synthesis parameters with defect states, (ii) systematic correlation of defect states with photocatalytic efficiency, and (iii) ZnO nanorods synthesized at 300 °C via an improved synthesis method as a promising photocatalytic solution to degrade the CV and CR dyes in contaminated water.

Fabrication of two-dimensional biotite nanosheets from natural biotite clay as a potent antibacterial agent

Since graphene’s exodus, layered materials’ exfoliation to two-dimensional (2D) nanosheets has attracted much attention. The primary layered materials are composed of weak van der Waals interlayer forces and strong intralayer bonds. Biotite (BTT) is one of the members of mica clays, which has stronger interlayer forces. In this study, three various procedures have been reported to exfoliate BTT. In the first method, ultrasound waves weakened the interlayer forces and so caused the exfoliation of the BTT to 2D nanosheets. In the second route, thermal and facile exfoliation of BTT intercalated compounds were combined. In the third one, a thermal exfoliation method was performed. These improved synthesis methods for producing few-layered exfoliated BTT (BTN) nanosheets, which are cost-effective, reproducible, and scalable, obtained BTNs with thicknesses of 10–50 nm, while the specific surface areas were increased by 4 times. The high specific surface area and sharp edges of BTN provide higher potentials for the decomposition of Escherichia coli and Staphylococcus aureus cells. The bactericidal effect of the BTNs against different bacteria was evaluated through the colony-forming unit (CFU) procedure and the minimum inhibitory concentration (MIC) quantities was subsequently measured. According to the results, after exfoliation, the antibacterial performance was improved about 8 times.

Bifunctional Adsorbents Based on Jarosites for Removal of Inorganic Micropollutants from Water

This paper presents a novel family of jarosites with the molecular formula MFe3(SO4)2(OH)6·xH2O; M = Na, K, NH4 that have high efficiency in the adsorption of As(V) and Pb(II) dissolved in water. The jarosites have been prepared by conventional heating at temperatures close to 95 °C for 3 h. The synthesis method was improved and optimized to reduce the time and energy consumption. The improved conventional heating method allowed for the synthesis of Na− and K−jarosites with a yield of up to 97.8 wt.% at 105 and 150 °C, respectively, in 3 h. The Na−, K−, and NH4−jarosites were synthesized at 150 °C in 5 min via a microwave-assisted method, which yielded jarosite crystalline agglomerates with more uniform topography, shape, and size than the conventional method. Both methods allowed the selective synthesis of jarosites. Chemical decomposition of jarosites suspended in water occurred at a pH less than 2 and higher than 10 and temperatures up to 150 °C. In the solid state, the jarosites were thermally stable at least to 300 °C. The Na−jarosite presented a maximum adsorption capacity (Qmax) of 65.6 mg g−1 for As(V) and 94 mg g−1 for Pb(II). The jarosites are considered promising bifunctional adsorbents for the remediation of contaminated water due to their improved synthesis method, stability, and high adsorption capacity for ions of different natures.

Liquid-Metal-Assisted Synthesis of Single-Crystalline TiC Nanocubes with Exposed {100} Facets for Enhanced Electrocatalytic Activity in the Hydrogen Evolution Reaction.

Although TiC nanostructures show promise as non-noble-metal-based electrocatalysts, improved synthesis methods are required. Herein, single-crystalline TiC nanocubes with exposed {100} facets are grown by combusting TiO2 + kMg + C reactive mixtures (k= 4-6.5mol) in argon. During the synthesis, the temperature increases to 1200-1550°C and excess Mg (2-4.5mol) forms a liquid pool. The obtained TiC nanocubes have edge lengths of 50-300nm and surface areas of 12.2-30.05 m2 g-1 . Insights into the TiC nanocube formation mechanism are obtained using density functional theory modeling of the surface energies of TiC nanocrystals and shape visualization using the Wulff construction method. During TiC nucleation and growth within the Mg melt, liquid Mg likely acts as a capping agent for {111} facets, thus promoting the formation of {100} facets. The TiC nanocubes show high electrocatalytic activity for the hydrogen evolution reaction, with a lower overpotential (0.298V at 10mA cm-2 ) than other TiC nanostructures (0.400-0.815V).

Enabling Aqueous Processing of Prussian White Cathodes for Sodium Ion Cells By Understanding the Effect of Structural Water

Sodium-ion batteries (SIBs) have been identified as one of the most promising alternative technologies for future stationary large-scale storage and light electromobility applications. Indeed, the potential cost decrease with respect to the lithium-ion technology, and the sustainability provided by using Earth abundant elements lead to lower economic and geopolitical impact.[1,2] Great achievements in terms of materials development have been reported in the recent years. However, further work is still needed to fully understand the structure-function correlation in several SIB materials. Easy-synthesis Prussian blue analogues (PBAs) have attracted much attention as potential cathode material in SIBs. Their open framework structure with large interstitial spaces allows a range of different compositions and enables fast Na+ insertion/extraction. However, a key factor affecting the electrochemical performance of PBAs is the crystal water in the structure arising from aqueous synthesis environments.[3] Thus, many have investigated improved synthesis methods aiming at reducing crystal water and associated structural defects.[4] Goodenough et al[5] firstly reported the improved electrochemical stability of PBAs through dehydration converting Na-rich monoclinic Na2MnFe(CN)6 to a rhombohedral structure. More recent studies, including Zhou et al[6] and Chou et al[7], further highlighted the negative impact of structural water on electrochemical performance. So far, the water sensitivity of PBAs has hindered aqueous electrode processing as demonstrated by the several studies conducted on N-methyl pyrrolidone-based electrodes. A more comprehensive understanding of the effect of crystal water and the induced degradation processes is necessary for obtaining high-performance electrode materials produced through environmentally friendly aqueous processing.Herein, we investigate the electrochemical behaviour of an aqueous-processed Fe-based Prussian white (PW) cathode material (Na2-x Fe[Fe(CN)6]1-y·zH2O).[8] The use of such material and processing matches the requirements for low toxicity, cost, and resource abundance in large-scale applications. We uniquely show that, by carefully tuning the water content in the PW structure, the electrochemical performance can be significantly improved. As structural water is removed by tuning the temperature and vacuum conditions during the electrode preparation, the crystallinity of the structure can be controlled, and optimal electrochemical behaviour can be achieved. Moreover, with the combination of cyclic voltammetry, impedance spectroscopy, X-Ray diffraction, X-ray absorption spectroscopy and scanning electron microscopy, we elucidate the activity of the low spin/ high spin Fe2+/3+redox reactions, the Na+ transport properties and the electrode’s structural and morphological changes. This allows to understand holistically the effect of crystal water on the electrochemical performance of PW cathodes. We then demonstrate that our approach is scalable and can be applied to different cell formats representing a step forward in the upscale of sustainable and low-cost sodium-ion cells.

Well-defined Co-N-C catalyst based on ZIF-67 in mixed solvents with low amount of ligands for efficient oxygen reduction reaction

Non-precious metal nitrogen-carbon composites (M-N-C) derived from ZIFs are an excellent non-precious metal catalyst for use in energy conversion and storage devices such as fuel cells and metal-air batteries. Herein ZIF-67 precursor with good dispersion, perfect crystal structure and size of below 270 nm was synthesized by consuming low amount of 2-methylimidazole ligand using a mixture of ethanol (EA) and methanol (MT) as the reaction medium. Compared with the traditional method of reducing the size of ZIF-67 by increasing the amount of ligands in methanol, this method avoids the waste of raw materials and saves the cost. The Co-N-C-MT/EA catalysts derived from ZIF-67 exhibits good ORR activity in alkaline media (0.1 M KOH) with a half-wave potential of 0.81 V vs RHE. After 5000 cycles, the initial potential and half-wave potential basically remain no change, showing excellent long-term stability. And remarkable methanol resistance is also displayed comparing with commercial Pt/C. The present experimental result shows that the improved synthesis method of ZIF-67 precursors has far-reaching implications for the field of catalyst research.

An improved method for synthesis of non-symmetric triarylpyridines

The optimization of a multicomponent reaction, to prepare triarylpyridines (triphenylpyridine), and which includes 17 examples where each aryl substituent is distinct (non-symmetric pyridine) is reported. The non-symmetric triarylpyridine aqrar forming reaction involves the sequential addition of two different acetophenones to a benzylamine in DMF in the presence of copper (I) iodide (20 mol %), methanolic ammonia (2 equiv.), and oxygen. The optimized method was used to give twenty five different triarylpyridines in 43–91% yield, including products with a thiophene substituent and bipyridines.

Facile and Rapid Synthesis of Porous Hydrated V2O5 Nanoflakes for High-Performance Zinc Ion Battery Applications.

Hydrated V2O5 with unique physical and chemical characteristics has been widely used in various function devices, including solar cells, catalysts, electrochromic windows, supercapacitors, and batteries. Recently, it has attracted extensive attention because of the enormous potential for the high-performance aqueous zinc ion battery cathode. Although great progress has been made in developing applications of hydrated V2O5, little research focuses on improving current synthesis methods, which have disadvantages of massive energy consumption, tedious reaction time, and/or low efficiency. Herein, an improved synthesis method is developed for hydrated V2O5 nanoflakes according to the phenomenon that the reactions between V2O5 and peroxide can be dramatically accelerated with low-temperature heating. Porous hydrated V2O5 nanoflake gel was obtained from cheap raw materials at 40 °C in 30 min. It shows a high specific capacity, of 346.6 mAh/g, at 0.1 A/g; retains 55.2% of that at 20 A/g; and retains a specific capacity of 221.0 mAh/g after 1800 charging/discharging cycles at 1 A/g as an aqueous zinc ion battery cathode material. This work provides a highly facile and rapid synthesis method for hydrated V2O5, which may favor its applications in energy storage and other functional devices.

An Improved Synthesis Method Based on ILPP and Colored Petri Net for Liveness Enforcing Controller of Flexible Manufacturing Systems

Petri nets are used to design deadlock control strategies for flexible manufacturing systems (FMS), which typically involve the addition of monitors and the associated arcs to the FMS. The addition of several monitors and associated arcs to first constructed Petri net model significantly complicates the Petri net controller. This paper develops a two-step method for preventing deadlocks based on a colored Petri net and a structurally minimal approach that significantly reduces the number of monitors. In the first step, a vector covering technique is applied to generate a minimal covered sets of first-met bad markings (FBMs) and legal markings that are respectively smaller than the sets of FBMs and legal markings. At one iteration, place invariants (PIs) corresponding to monitors are constructed by solving an integer linear programming problem (ILPP) to prohibit the maximum number of FBMs, while allowing all legal markings in the minimal covering set. The purpose of the ILPP is to maximize the number of FBMs forbidden by the PIs. Then, based on a colored Petri net, all generated monitors are combined into a global control place. Therefore, a supervisor with minimal structural complexity can be constructed. The obtained net model is controlled after the addition of the designed supervisor. Two instances from the literature are considered to illustrate the proposed approach.

Generation Method of Target Power Spectral Density for Seismic Design of Nuclear Power Plant Equipment

The input ground motion for the seismic design of nuclear power plant (NPP) equipment is required to envelop both the required response spectrum (RRS) and target power spectral density (PSD). However, no unified algorithm exists to generate the target PSD, whether at home or abroad. Based on the generation methodology for target PSD suggested in Section 3.7.1 of the Standard Review Plan (SRP) of U.S. Nuclear Regulatory Commission, this paper proposes an improved method for target PSD synthesis with the original iteration process optimized. The proposed method is applied successfully to the two RRS cases for nuclear equipment. The result shows that the improved method for target PSD generation is highly compatible with RRS and provides simple and rapid calculation, while its convergence accuracy is similar to the calculations by random vibration theory (RVT). This method is considered as the target PSD test basis for the input artificial ground motion (AGM) for the seismic design of NPP equipment.

Amide-functionalized graphene-assembled monoliths with high adsorption capacity of Cd2+

Three-dimensional graphene-assembled monoliths (GAs) are emerging materials used in supercapacitors, catalysis, etc. However, GAs prepared by mainstream reduction methods (reduced GAs, RGAs) have fewer functional groups and display poor adsorption capacity of heavy metals. In this paper, we developed a new method of preparing amide-functionalized GAs (AGAs) with high degree of modification by the reaction of carboxyl-functionalized graphene oxides and ethylenediamine. AGAs contained multiple functional groups and exhibited dendritic structure at micron scale. Benefiting from these properties, the maximum adsorption capacities Cd 2 + on AGAs at T = 303 K were about 56.6 mg/g, which was twice that of RGAs and higher than that of graphene ( ∼ 10 mg/g) and biochar ( ∼ 18 mg/g) at the same conditions. By calculating the Gibbs free energies ( Δ G), the adsorption of Cd 2 + on AGAs was proved a spontaneous process, while the adsorption of Cd 2 + on RGAs was not spontaneous X-ray photoelectron spectroscopy analysis demonstrated that AGAs contained more adsorption sites and Cd 2 + adsorbed on AGAs through coordination bond. Thus, AGAs exhibited good application potentials as adsorbents for the removal of Cd 2 + from contaminated water. • GAs with rich functional groups were successfully prepared. • The three-dimensional structure was constructed by forming amide groups. • Compared with RGAs, AGAs had more potential adsorption sites for heavy metals. • Compared with RGAs, AGAs had higher adsorption capacity for Cd 2+ at 30 °C. • The improved synthesis method makes the adsorption of Cd 2+ by AGAs spontaneous.

Synthesis and bioconjugation of alkanethiol-stabilized gold bipyramid nanoparticles

Gold bipyramid (GBP) nanoparticles are promising for a range of biomedical applications, including biosensing and surface-enhanced Raman spectroscopy, due to their favorable optical properties and ease of chemical functionalization. Here we report improved synthesis methods, including preparation of gold seed particles with an increased shelf life of ∼1 month, and preparation of GBPs with significantly shortened synthesis time (< 1 h). We also report methods for the functionalization and bioconjugation of the GBPs, including functionalization with alkanethiol self-assembled monolayers (SAMs) and bioconjugation with proteins via carbodiimide cross-linking. Binding of specific antibodies to the nanoparticle-bound proteins was subsequently observed via localized surface plasmon resonance sensing. Rabbit IgG and goat anti-Rabbit IgG antibodies were used as a model system for antibody-antigen interactions. As-synthesized, SAM-functionalized, and bioconjugated bipyramids were characterized using scanning electron microscopy, UV–vis spectroscopy, zeta potential, and dynamic light scattering.

High electrical conductivity and breakdown current density of individual monolayer Ti3C2Tx MXene flakes

High electrical conductivity and breakdown current density of individual monolayer Ti3C2Tx MXene flakes

Impacts sur l’activité biologique de surfaces d’implants métalliques chimiquement différents couverts d’un composite de facteur de croissance des fibroblastes-2 (FGF-2) et d’apatite

BackgroundImplants coated with fibroblast growth factor-2 (FGF-2) – apatite composite layers were previously reported to enhance soft-tissue formation, bone formation, and angiogenesis around the implants owing to the biological activity of FGF-2. However, it is unclear whether the chemistries of the material and surface of implants have some impact on the retention of the biological activity of FGF-2 in FGF-2 – apatite composite layers on them. Since magnitude of the impact should be evaluated for extensive application of the composite layer to coat various implants, following items were examined: (1) surface chemistries of six implants; (2) mitogenic activities of FGF-2 in FGF-2 – apatite composite layers on the implants; and (3) improved synthesis method of the composite layer for retention of the mitogenic activity of FGF-2. HypothesisThe biological activity of FGF-2 in the composite layer is affected by the chemistries of the material and surface of implants. Materials and methodsSix commercial products of pins and screws having different surface chemistries were coated with FGF-2 – apatite composite layers. The composite layers were quantitatively analyzed for calcium (Ca), phosphorus (P) and FGF-2, and also evaluated the mitogenic activities of FGF-2. Improvement of the synthesis method was then attempted using two pin products. ResultsEach commercial product had a chemically and morphologically characteristic surface. FGF-2 – apatite composite layers were formed on all the commercial products. Although the Ca, P, and FGF-2 contents (4.7±0.9μg/mm, 2.2±0.4μg/mm, and 21.1±3.7ng/mm, respectively) and the Ca/P molar ratios (1.69±0.01) of the composite layers were almost the same, rate of retention of the mitogenic activity of FGF-2 in the composite layers significantly decreased on some pin products (3/12–4/12). The decrease in rate of retention of the mitogenic activity of FGF-2 was prevented by a two-step synthesis method to form a composite layer on a precoating with calcium phosphate (9/12–12/12). DiscussionThe chemistries of the implant surfaces had a significant impact on the retention of the mitogenic activity of FGF-2 in the composite layers formed on the implant. The two-step synthesis method was useful to retain mitogenic activity of FGF-2 regardless of the surface chemistries of the implants. The two-step synthesis method has potential to expand the applicability of FGF-2 – apatite composite layers to a wider range of implants. Level of evidenceIII, case control in vitro study.