Graphene Flakes Research Articles

Graphene functionalized nanoencapsulated composite phase change material based nanofluid for battery cooling: An experimental investigation

The graphene-nano encapsulated composite phase change material (GnePCM) based nanofluid holds great potential as a coolant for batteries in electric vehicles. The current work focuses on the synthesis and study of the cooling performance of GnePCM-based nanofluid. Few layered graphene (FLG) was synthesized via the liquid phase exfoliation method. Mini-emulsion polymerization was adopted to encapsulate composite PCM (octadecane: paraffin wax) within polystyrene shell and distribute these nanoballs across the graphene flakes of FLG to obtain GnePCM. Differential Scanning Calorimetry (DSC) was used to optimize the composition of composite PCM based on the melting range and latent heat. GnePCM was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), DSC, Fourier Transform Infrared (FTIR) spectroscopy, and Raman Spectroscopy. Nanofluid was made by mixing GnePCM slurry with the base fluid (ethylene glycol − water mixture) and its thermo-physical properties were estimated. The analysis of thermal conductivity and specific heat capacity showed a 14.7 % and 56 % increase for the nanofluid compared to the base fluid. The optimal concentration of nanofluid for maximum stability was 10 % v/v based on zeta potential measurements. The heat transfer studies and pressure drop studies were conducted on a set of 10 cylindrical heaters, mimicking a 18,650 battery cell pack. The nanofluid could potentially achieve a maximum reduction of 5 °C in average surface temperatures of the cells as compared to the base fluid. The enhanced cooling efficiency of nanofluid could be related to the increased thermal conductivity and heat capacity of GnePCM, as well as the absorption of latent heat during its melting process. Enhancement in heat transfer parameters was found to be more prominent at lower flow rates for the nanofluids. The results reveal that the flow rate and power input play a significant role in the cooling performance of the nanofluid. Due to the increased viscosity of the nanofluid, a slight increase in the pressure drop and pumping power was observed at higher flow rates, as compared to base fluid.

Electronic Structure Simulations of the Platinum/Support/Ionomer Interface in Proton Exchange Membrane Fuel Cells

ABSTRACTIn this work, we present electronic structure calculations to quantify and rationalize the interactions between catalyst, support, ionomer, and active molecular species in proton exchange membrane fuel cells. Quantifying interaction energies and their scaling with size allows us to rationalize and compare the fundamental driving forces behind structure formation and material properties. Our basic approach involves simplifying the most important interactions between different components using smaller model systems, such as limited‐size platinum nanoparticles, polyaromatic hydrocarbons (graphene flakes), and fragments of various functional units of the Nafion ionomer while applying unbiased first‐principles (density functional theory) simulation methods. To guide this quantification, we propose an analysis based on the linear dependence of interaction energy on the number of interacting atom pairs in the interface. This enables us to compare and categorize interactions between catalyst, ionomer, and support with interactions like catalyst–reactant and catalyst–catalyst poison.

Interfacical polarization dominant rGO aerogel decorated with molybdenum sulfide towards lightweight and high-performance electromagnetic wave absorber

Lightweight reduced graphene oxide aerogel (rGO) has obtained enormous attention as microwave absorber due to anisotropic characteristics in their structure and electromagnetic parameters. However, the controllable preparation of reduced graphene oxide (rGO) aerogels with tailored multidimensional structure with broadened effective absorption bandwidth is a thorny difficulty. In this paper, rGO aerogel decorated with molybdenum sulfide (rGO/MoS2) with three-dimensional (3D) layered porous structure were synthesized by a two-step hydrothermal method. The unique three-dimensional layered porous structure of graphene aerogel not only effectively avoids the stacking of graphene flake layers, but also provides space for the loading of MoS2 nanosheets. The introduction of MoS2 nanosheets compensates for the imbalance of impedance matching caused by graphene due to the excessive conductivity, and the folded MoS2 nanosheets are uniformly loaded on the graphene lamellae, which is conducive to generate multiple reflections and scattering of electromagnetic waves. Besides, the construction of heterogeneous interfaces strengthens the interfacial polarizability of the composites. As a result, excellent electromagnetic wave attenuation properties were obtained for rGO/MoS2, and the effective absorption bandwidth (EAB) reached 6.56 GHz at 2.1 mm. In addition, the radar cross section (RCS) simulation results further demonstrate the dissipation capability of the composite in practical application scenarios. This paper provides a new idea for the design of lightweight EM wave absorbing materials with broad absorption bandwidth.

Adsorption of As nano-clusters on different graphene environments

We investigate the adsorption of As nano-clusters on graphene sheets in various environments, including vacancies and anchors with Fe and/or O impurities. To achieve this, we conducted Density-Functional Theoretical (DFT) calculations using the freely distributed SIESTA code. Our findings reveal a direct correlation between the number of vacancies and the adsorption energy, indicating that a higher number of vacancies result in higher adsorption of As-clusters. Additionally, as the Asn-cluster size increases, the adsorption energy decreases. Furthermore, our results suggest that transition metal impurities (such as Fe) serve as effective elements for functionalizing graphene facilitating the adsorption of metallic clusters in this way, making it suitable for applications in wastewater filtration or the purification of toxic elements in water. Finally, we address finite size effects on the adsorption of graphene sheets by perform calculations on graphene flakes of different sizes saturated in different ways.

Recycling primary batteries into advanced graphene flake-based multifunctional smart textiles for energy storage, strain sensing, electromagnetic interference shielding, antibacterial, and deicing applications

Batteries are extensively used owing to their pivotal role in energy storage. However, their adverse environmental impact remains a significant challenge. The prevailing technologies for treating and handling battery waste are remarkably complex and expensive, highlighting the urgent need to upcycle spent battery materials into valuable resources to mitigate their environmental footprint. To that end, this paper reports a scheme for recycling graphite rods and Zn from Zn–C batteries. In this approach, polymeric composites synthesized using graphene flakes extracted from the graphite rods of spent batteries are used to fabricate multifunctional cotton textiles, and the outer Zn case of the spent batteries is employed as a Zn anode in energy storage devices. The synthesized multifunctional fabric shows excellent energy storage performance, particularly in Zn-ion hybrid supercapacitors, achieving a specific capacitance of 140 F g−1 at a scan rate of 0.5 A g−1; an electromagnetic interference shielding efficiency of ∼48 dB; wearable sensing capabilities for human motion detection; and Joule heating behavior for deicing. Moreover, the fabric exhibits remarkable antibacterial efficiency, with an approximately 27-mm-wide inhibition zone against both Gram-positive and Gram-negative bacteria. The “waste-to-wonder” strategy presented herein holds promise for environmental protection and innovative multifunctional textile fabrication.

Dirac Electrons in Graphene Flakes

Dirac Electrons in Graphene Flakes

Single-atom catalysts (SACs) for CO2 to CO conversion using cu, ni, and co on graphene flakes support; a DFT study

In this study, to convert the CO2 to more useful compound and in order to design the appropriate catalyst for this conversion, a graphene flakes support was considered for three transition metals of the 3d series (Cu, Co and Ni) as single-atom catalysts. Although different spin multiplicities for cobalt and nickel catalysts are possible, their relative energies and frontier orbital properties suggested the catalyst with the higher spin multiplicity is more suitable for this purpose. Moreover, to develop the mechanism of this conversion, two mechanistic routes were designed for the reaction and the structures of all reactants, products, intermediates and transition states of these routes were optimized and their enthalpies and Gibbs free energies were extracted. The final data showed that by the gas phase calculation, copper and cobalt are more favorable than nickel catalyst; copper is thermodynamically favorable and cobalt is kinetically favorable. The solvent effects were also considered using water and PCM methods, which showed, the solvent facilitate the reaction, especially for cobalt; therefore, in the solvent cobalt (and then, copper) is the most appropriate catalyst by both thermodynamic and kinetic data.

Lightweight composite from graphene-coated hollow glass microspheres for microwave absorption

In developing the effective and lightweight materials for microwave absorption, graphene holds a bright promise because of its excellent electrical properties and low density, but it suffers from poor impedance matching; while the hollow glass microspheres on the other hand have extremely low density and are dielectric. Their synergistic combination could achieve a perfect impedance matching and thus create a novel lightweight absorption composite. The metamaterial structure absorber can efficiently absorb electromagnetic waves over a wide frequency range. This study employs a hydrothermal method to deposit graphene onto the surfaces of hollow glass microspheres, followed by the design of a metamaterial absorber. Upon coating with graphene flakes, the composite material effectively dissipates electromagnetic wave energy through mechanisms such as interfacial polarization, dielectric loss, and the multiple scattering effects of hollow glass microspheres and graphene flakes. The composite exhibits an effective absorption bandwidth up to 4.02 GHz under a graphene flakes mass fraction of 30 %. More importantly, the incorporation of the metamaterial absorber design further significantly enhances the absorption bandwidth to 7.7 GHz. This material demonstrates significant advantages in terms of lightweight and broadband absorption performance, providing new insights for the research of high-performance lightweight and wideband absorbing materials in the future. However, further investigation is required to examine its long-term stability and performance in complex environments.

Experimental comparison of the effects of the two designed probes for exfoliation of graphene by sonication.

In the present research, comparative simulation and experimental investigation were carried out for two different probes to improve the efficiency and quality of few-layer graphene utilizing liquid-phase exfoliation. Two differently designed shaped probes are fabricated for this study, i.e., a simple probe and a stepped probe. The acoustic pressure distribution in the vessel is simulated for both probes at different output powers. In the experiment, both probes exfoliate graphite powder in a mixture of deionized water and ethanol. Different sonication times and output power were studied for different pulse modes. The graphene layers were characterized using Ultraviolet-visible spectroscopy (UV‒Vis), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Raman Microscope. The simulation shows that the total displacement on the tip of the stepped probe is 5.7% greater than that of the simple probe. Also, the pressure difference produced by the stepped probe is 9.15 × 106 pa compared to the pressure difference of the simple probe which is 8.23 × 106 pa. Consequently, the stepped probe was more effective in exfoliating graphene. The experimental results show that the absorbance peak in the stepped probe is approximately 32% greater than the absorbance peak in the simple probe with the same output power. Also, the graphene with better quality is produced with the stepped probe compared to the simple probe, which verifies the simulation findings. Additionally, the optimum output power, pulse duration, and sonication time to produce graphene with less time and energy consumption are obtained. The best graphene flakes were obtained via sonication with a pulse duration of 0.7 s, an output power of 282 W, and a sonication time of 45 min using a stepped probe. UV-Vis., SEM and TEM analysis show increases in quantity and quality of the exfoliated flakes. These results are approved by the peak ratio of I2D/IG around 1 in Raman spectra revealed the production of the few-layer graphene by the simple probe and the bilayer graphene by the stepped probe. So, this method is suitable for the production of graphene flakes from graphite in suitable quantity and quality.

Upcycling the Spent Graphite Anode Into the Prelithiation Catalyst: A Separator Strategy Toward Anode-Free Cell Prototyping.

The substantial manufacturing of lithium-ion batteries (LIBs) requires sustainable, circular, and decarbonized recycling strategies. While efforts are concentrated on extracting valuable metals from cathodes using intricate chemical process, the direct, efficient cathode regeneration remains a technological challenge. More urgently, the battery supply chain also requires the value-added exploitation of retired anodes. Here, a "closed-loop" approach is proposed to upcycle spent graphite into the prelithiation catalyst, namely the fewer-layer graphene flakes (FGF), upon the exquisite tuning of interlayer spacing and defect concentration. Since the catalytic FGF mitigates the delithiation energy barrier from calcinated Li5FeO4 nanocrystalline, the composite layer of which cast on the polyolefin substrate thus enables a customized prelithiation capability (98% Li+ utilization) for the retired LiFePO4 recovery. Furthermore, the hydrophobic polymeric modification guarantees the moisture tolerance of Li5FeO4 agents, aligning with commercial battery manufacturing standards. The separator strategy well regulates the interfacial chemistry in the anode-free pouch cell (LiFePO4||Cu), the prototype of which balances the robust cyclability, energy density up to 386.6Wh kg-1 as well as the extreme power output of 1159.8W kg-1. This study not only fulfills the sustainable supply chain with graphite upcycling, but also establishes a generic, viable protocol for the anode-free cell prototyping.

Graphene Decorated With Mo3S7 Clusters for Sensing CO2

AbstractThis paper reports for the first time a gas‐sensitive nanohybrid based on trinuclear molybdenum sulfido clusters ((Bu4N)2[Mo3(μ3‐S)(μ‐S2)3Cl6] (Mo3S7)) supported on graphene flakes (Mo3S7@Graphene). The nanomaterial, once implemented in a chemoresistive device, changes its electrical resistivity when exposed, at room temperature (RT), to toxic and harmful gases, such as hydrogen (H2), carbon dioxide (CO2), carbon monoxide (CO), and benzene. Particularly, the Mo3S7@Graphene hybrid shows an outstanding sensing performance toward CO2. Theoretical calculations provide a better understanding of the plausible gas sensing mechanisms. These findings open the door for a new generation of molybdenum sulfido cluster‐based sensors in which electronic interrogation can be implemented, advancing toward the realization of highly sensitive gas sensing.

Roller-like Spore Carbon Sphere-Orientated Graphene Fibers Prepared via Rheological Engineering for Lithium Sulfur Batteries.

Flexible batteries with large energy densities, lightweight nature, and high mechanical strength are considered as an eager goal for portable electronics. Herein, we first propose free-standing graphene fiber electrodes containing roller-like orientated spore carbon spheres via rheological engineering. With the help of the orientated microfluidic cospinning technology and the plasma reduction method, spore carbon spheres are self-assembled and orientedly dispersed into numerous graphene flakes, forming graphene fiber electrodes enriched with internal rolling woven structures, which cannot only enhance the electrical contact between active materials but also effectively improve the mechanical strength and structure stability of graphene fiber electrodes. When the designed graphene fibers are combined with the active sulfur cathode and lithium metal anode, the assembled flexible lithium sulfur batteries possess superior electrochemical performance with high capacity (>1000 mA h g-1) and excellent cycling life as well as good mechanical properties. According to density functional theory and COMSOL simulations, the roller-like spore carbon sphere-orientated graphene fiber hosts provide reinforced trapping-catalytic-conversion behavior to soluble polysulfides and nucleation active sites to lithium metal, thus synergistically suppressing the shuttle effect of polysulfides at the cathode side and lithium dendrite growth at the anode side, thereby boosting the whole electrochemical properties of lithium sulfur batteries.

Impact of the Graphene Production Methods Sonication and Microfluidization on In Vitro and In Vivo Toxicity, Macrophage Response, and Complement Activation.

Graphene, a material composed of a two-dimensional lattice of carbon atoms, has due to its many unique properties a wide array of potential applications in the biomedical field. One of the most common production methods is exfoliation through sonication, which is simple but has low yields. Another approach, using microfluidization, has shown promise through its scalability for commercial production. Regardless of their production method, materials made for biomedical applications need to be tested for biocompatibility. Here, we investigated the differences in toxicity, macrophage response, and complement activation of similar-sized graphene flakes produced through sonication and microfluidization, using in vitro cell assays and in vivo assays on zebrafish larvae. In vitro toxicity testing showed that sonicated graphene had a high toxicity, with an EC50 of 100 μg mL-1 for endothelial cells and 60 μg mL-1 for carcinoma cells. In contrast, microfluidized graphene did not reach EC50 at any of the tested concentrations. The potency to activate the complement system in whole blood was 10-fold higher for sonicated than for microfluidized graphene. In zebrafish larvae, graphene of either production method was found to mainly agglomerate in the caudal hematopoietic tissue; however, no acute toxic effects were found. Sonicated graphene led to an increase in macrophage count and a macrophage migration to the ventral tail area, while microfluidized graphene led to a transient reduction in macrophage count and fewer cells in the ventral trail area. The observed reduction in macrophages and change in macrophage distribution following exposure to microfluidized graphene was less pronounced compared to sonicated graphene and contributed to masking of the fluorescent signal rather than cytotoxic effects. Summarized, we observed higher toxicity, macrophage response, and complement activation with graphene produced through sonication, which could be due to oxygen-containing functional groups introduced to the edge of the carbon lattice by this production method. These findings indicate that microfluidization produces graphene more suitable for biomedical applications.

Nanocarbon-Polymer Composites for Next-Generation Breast Implant Materials.

Most breast implants currently used in both reconstructive and cosmetic surgery have a silicone outer shell, which, despite much progress, remains susceptible to mechanical failure, infection, and foreign body response. This study shows that the durability and biocompatibility of breast implant-grade silicone can be enhanced by incorporating carbon nanomaterials of sp2 and sp3 hybridization into the polymer matrix and onto its surface. Plasma treatment of the implant surface can be used to modify platelet adhesion and activation to prevent thrombosis, postoperative infection, and inflammation disorders. The addition of 0.8% graphene flakes resulted in an increase in mechanical strength by 64% and rupture strength by around 77% when compared to pure silicone, whereas when nanodiamond (ND) was used as the additive, the mechanical strength was increased by 19.4% and rupture strength by 37.5%. Composites with a partially embedded surface layer of either graphene or ND showed superior antimicrobial activity and biocompatibility compared to pure silicone. All composite materials were able to sustain the attachment and growth of human dermal fibroblast, with the preferred growth noted on ND-coated surfaces when compared to graphene-coated surfaces. Exposure of these materials to hydrogen plasma for 5, 10, and 20 s led to substantially reduced platelet attachment on the surfaces. Hydrogen-treated pure silicone showed a decrease in platelet attachment for samples treated for 5-20 s, whereas silicone composite showed an almost threefold decrease in platelet attachment for the same plasma treatment times. The absence of platelet activation on the surface of composite materials suggests a significant improvement in hemocompatibility of the material.

Decoupled High-Mobility Graphene on Cu(111)/Sapphire via Chemical Vapor Deposition.

The growth of high-quality graphene on flat and rigid templates, such as metal thin films on insulating wafers, is regarded as a key enabler for technologies based on 2D materials. In this work, the growth of decoupled graphene is introduced via non-reducing low-pressure chemical vapor deposition (LPCVD) on crystalline Cu(111) films deposited on sapphire. The resulting film is atomically flat, with no detectable cracks or ripples, and lies atop of a thin Cu2O layer, as confirmed by microscopy, diffraction, and spectroscopy analyses. Post-growth treatment of the partially decoupled graphene enables full and uniform oxidation of the interface, greatly simplifying subsequent transfer processes, particularly dry-pick up - a task that proves challenging when dealing with graphene directly synthesized on metallic Cu(111). Electrical transport measurements reveal high carrier mobility at room temperature, exceeding 104cm2V-1s-1 on SiO2/Si and 105cm2V-1s-1 upon encapsulation in hexagonal boron nitride (hBN). The demonstrated growth approach yields exceptional material quality, in line with micro-mechanically exfoliated graphene flakes, and thus paves the way toward large-scale production of pristine graphene suitable for high-performance next-generation applications.

Tree-Inspired Aerogel Comprising Nonoxidized Graphene Flakes and Cellulose as Solar Absorber for Efficient Water Generation.

As global freshwater shortages worsen, solar steam generation (SSG) emerges as a promising, eco-friendly, and cost-effective solution for water purification. However, widespread SSG implementation requires efficient photothermal materials and solar evaporators that integrate enhanced light-to-heat conversion, rapid water transportation, and optimal thermal management. This study investigates using nonoxidized graphene flakes (NOGF) with negligible defects as photothermal materials capable of absorbing over 98% of sunlight. By combining NOGF with cellulose nanofibers (CNF) through bidirectional freeze casting, we created a vertically and radially aligned solar evaporator. The hybrid aerogel exhibited exceptional solar absorption, efficient solar-to-thermal conversion, and improved surface wettability. Inspired by tree structures, our design ensures rapid water supply while minimizing heat loss. With low NOGF content (∼10.0%), the NOGF/CNF aerogel achieves a solar steam generation rate of 2.39 kg m-2 h-1 with an energy conversion efficiency of 93.7% under 1-sun illumination, promising applications in seawater desalination and wastewater purification.

Comprehensive study of optical contrast, reflectance, and Raman spectroscopy of multilayer graphene

Graphene research has developed quite rapidly partially because even a monatomic layer can be visualized with a conventional optical microscope. Although optical properties of multilayer graphene such as optical contrast, reflectance (R), and Raman scattering have been well studied, they are studied independently and the thickness dependence is limited to a rather thin region. In this paper, the evolution of optical properties by thickness from monolayer to multilayer graphene up to 107 nm thick is studied comprehensively. The empirically known change of color of multilayer graphene is confirmed from the R, G and B intensities extracted from the optical images. It is also found that, as far as R for visible light is concerned, multilayer graphene is not necessarily considered as a layered material, and the refractive index for monolayer graphene is applicable even for the thickest multilayer graphene flake in this study. On the other hand, the layered structure and Raman scattering at each layer are essential to reproduce the G-band intensity of Raman scattering (I(G)). Not only the multiple reflection but also the interference of scattered Raman light should be considered for I(G) of multilayer graphene thicker than ∼30 nm.

(Invited) Architectural Refinement in Core-Shell Ni/Ni(OH)2 Nanowires Array for Enhanced Supercapacitor Performance - A Comprehensive Electrochemical and Finite Element Study

We investigated the electrochemical performance and effect of different aspect ratios of core-shell Ni/Ni(OH)2 nanowires arrayed in an asymmetric supercapacitor with graphene flakes. We created thenanowires with diameters of 35 nm, 100 nm, 150 nm and different height using electrodeposition with help of Anodic Alumina Oxide template, allowing us to regulate their dimensions accurately. We identified an intriguing trend: supercapacitor performance first rises with nanowire height, but then steadily drops when a critical threshold is reached. We used Finite Element Analysis (FEA) to corroborate our experimental results and uncover the underlying electrochemical processes in order to better explain and comprehend this phenomenon. According to the FEA simulations, the nanowire length effects the distribution and accessibility of ionic species surrounding the nanowire array, which influences the charge storage and transfer processes. Figure 1

ZnO-Graphene Oxide Nanocomposite for Paclitaxel Delivery and Enhanced Toxicity in Breast Cancer Cells.

A ZnO-Graphene oxide nanocomposite (Z-G) was prepared in order to exploit the biomedical features of each component in a single anticancer material. This was achieved by means of an environmentally friendly synthesis, taking place at a low temperature and without the involvement of toxic reagents. The product was physicochemically characterized. The ZnO-to-GO ratio was determined through thermogravimetric analysis, while scanning electron microscopy and transmission electron microscopy were used to provide insight into the morphology of the nanocomposite. Using energy-dispersive X-ray spectroscopy, it was possible to confirm that the graphene flakes were homogeneously coated with ZnO. The crystallite size of the ZnO nanoparticles in the new composite was determined using X-ray powder diffraction. The capacity of Z-G to enhance the toxicity of the anticancer drug Paclitaxel towards breast cancer cells was assessed via a cell viability study, showing the remarkable anticancer activity of the obtained system. Such results support the potential use of Z-G as an anticancer agent in combination with a common chemotherapeutic like Paclitaxel, leading to new chemotherapeutic formulations.

(Invited) Low Temperature Plasma Synthesis and Functionalisation of Carbon Nanostructures for Energy Conversion and Storage

Low-temperature plasmas are nowadays widely developed and used for synthesis and functionalization of various materials with applications in areas ranging from microelectronics and aeronautical industry to energy conversion and storage. The focus of the research and applications has lately shifted towards carbon and carbon-based materials synthesis. The materials of interest vary from nanoparticles, nanotubes, nanowalls, free standing graphene flakes, vertical graphene rods, sponge structures, nanostructured surfaces, to composites (with conductive or non-conductive polymers, or MoS2, to mention some of the examples that will be presented herein). The interest for direct applications of plasma processes as well as nanostructures in the field of energy conversion and storage has been present since a long time. Recently, however, several interesting fundamental breakthroughs have been observed in terms of better control of processes, diagnostics and several other benefits that are attracting more and more attention: lower temperatures of surfaces needed for synthesis and functionalization (due to active plasma species interacting with surfaces), dry processes (diluted precurors or liquid monomers introduced in processes, without use of solvents), decreased overall pollution, fast processes, to mention just some of the advantages. However, our work must not forget the disadvantages and problems that can occur during application tests, such as stability, adhesion, loss of conductivity, reproducibility, general ageing or recyclability.Different factors can affect the function of the final setup (from photocatalytic elements, to batteries or fuel cells/HER systems, in our case) – from production of the starting materials to the assembly. Therefore, careful synthesis and control of the process (including the chamber and surface conditions for example) is necessary. We present herein several examples of carbon materials developed or in development (as mentioned 1D-3D carbons, carbon in organic and inorganic composits, mesoporous carbons). These materials were synthesized at surface temperatures between room temperature and up to 550°C.We emphasize, for example, the importance of in-situ control of processes, the importance of precise process conditions, the control of the synthesized materials with regard to their electrical conductivity, adhesion, thermal stability or sensitivity to photon irradiation.Acknowledgments:Authors acknowledge the EU Graphene Flagship FLAG-ERA III JTC 2021 project VEGA (PR-11938) and the project PEGASUS (funded by the European Union's Horizon research and innovation programme under grant agreement No 766894. UC and NMS acknowledge the Slovenian Research Agency for the program ARRS No. P1-0417 and project Z2-4467. TS, EK and JB want to thank HZB for the allocation of synchrotron radiation beamtime at the HE-SGM beamline of BESSY II. Thanks goes also to Prof. Wöll from KIT for providing the HE-SGM endstation used for the XPS and NEXAFS measurements. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730872 (Nr. 18207084-ST and 18207393- ST). EK and JB acknowledge also support obtained via ARD MATEX Region Centre.