Supercritical CO2 Technology Research Articles

Corrigendum to “A fresh perspective to synthesizing and designing carbon/sulfur composite cathodes using supercritical CO2 technology for advanced Li-S battery cathodes” [J. Alloy. Compd. 1008 (2024) 176691]

Corrigendum to “A fresh perspective to synthesizing and designing carbon/sulfur composite cathodes using supercritical CO2 technology for advanced Li-S battery cathodes” [J. Alloy. Compd. 1008 (2024) 176691]

A fresh perspective to synthesizing and designing carbon/sulfur composite cathodes using supercritical CO2 technology for advanced Li-S battery cathodes

The morphology and surface chemistry of the sulfur host within lithium-sulfur (Li-S) batteries significantly influence the overall battery performance. To investigate this relationship, we employed a non-toxic heat treatment to produce reduced graphene oxide (rGO) with varying degrees of reduction, resulting in distinct surface chemistries. The physicochemical characteristics and electrochemical properties of four differently reduced GO samples and rGO/sulfur composite cathodes developed with supercritical CO2 technology were examined. Our study established a clear correlation between the specific surface area and porosity of rGO and the electrochemical performance of the corresponding rGO/sulfur composite cathodes. Notably, rGO samples reduced at 350°C (rGO350) exhibited superior discharge capacity and long-term cycling stability compared to those reduced at higher temperatures. This performance enhancement can be attributed to the combination of high surface area, porosity, and an open morphology in rGO350. These findings underscore the importance of optimizing carbon chemistry, microstructure, and cathode synthesis strategies in Li-S batteries. By effectively controlling sulfur loading and distribution within the rGO network, we can enhance active material utilization, boost electronic conductivity, and ensure the long-term stability of rGO/sulfur composite cathodes. Our research suggests that SC-CO2-assisted synthesis offers a promising approach for designing high-performance carbon/sulfur composite cathodes for Li-S batteries. This method provides a versatile platform for tailoring the rGO morphology and surface chemistry, optimizing battery performance. By carefully considering the interplay between these factors, we can unlock the full potential of Li-S batteries for various applications.

Biosensing of Cysteine through the Induction of Oxygen Vacancies in a Cu/Zr Heterostructure Prepared by Supercritical Antisolvent Technique.

There has been a growing emphasis on facile preparation of binary heterogeneous composite materials. Leveraging the eco-friendly efficiency of supercritical CO2 technology, we achieved precise control over the influencing factors of mass transfer, enabling the accurate modulation of the resulting product morphology and properties. In the current study, CuxO/ZrOy composite materials were prepared using this technology and calcined to obtain electrode materials for the detection of cysteine (Cys). Essential comprehensive characterization techniques were employed to elucidate the heterojunction. The resulting electrode demonstrated a linear response to Cys within a concentration range of 0.5 nM to 1 μM, featuring a high sensitivity of 1035 μA·cm-2·μM-1 and a low detection limit of 97.3 nM. Thus, establishing a novel avenue for nonenzyme-based electrochemical sensors tailored for biologically active Cys detection through the implementation of a heterogeneous structure.

Foaming of thermoplastic polyurethane using supercritical CO2 AND N2: Antishrinking strategy

The transformation of thermoplastic polyurethanes into polymeric foams is attracting great interest nowadays. However, this technology has some challenges that it is necessary to resolve, being one of the most important the shrinkage suffered by the polymeric foams over time. For that reason, this work explores several alternatives to mitigate this phenomenon. These alternatives are divided into two groups: on the one hand, the refoaming of the shrunken foams using supercritical CO2 and N2 was explored; on the other hand, the foaming using mixtures of supercritical CO2 and N2 as foaming agents was carried out. After experiments, it was seen that, the refoaming with N2 of shrunken foams obtained by supercritical CO2 technology can increase and keep constant the initial expansion ratio of the shrunken foams. Moreover, it was also observed that ratios of CO2/N2 between 80/20 and 60/40 can avoid the shrinking issues suffered by the polymeric foams after foaming using supercritical technology.

Encapsulation of Olive (Olea europaea L.) Pruning Waste Particles by Supercritical CO2 Technology.

Olive leaves (Olea europaea L.) contain a multitude of bioactive compounds such as sterols, carotenes, triterpenic alcohols and phenolic compounds. These compounds have been shown to exhibit antiviral, antioxidant, candida-growth-inhibitory, anticancer, antifungal, anti-inflammatory and antibacterial activities. In this sense, submicron particles from olive leaves with antioxidant activity were precipitated by supercritical antisolvent extraction in a previous work. Moreover, encapsulation enables the delayed release of compounds and avoids the first-step effect in medical therapies. Therefore, this work focused on encapsulation of particles with a certain antioxidant capacity from olive pruning waste using supercritical technology. A variety of experiments were carried out to test how the different operating variables (pressure, temperature and extract-polymer ratio) affect. Morphology was analyzed by SEM microscopy, obtaining encapsulates between 1 and 5 microns in size. The antioxidant capacity was determined by the DPPH assay, with most of the encapsulates having AAI values between 0.5 and 1 (moderate antioxidant capacity). An increase in polyphenol content was observed in the 1:3 ratio tests. The release of the compounds in gastric simulated medium was retarded by the polymeric encapsulation, while in intestinal fluid, the solubility was improved compared to the unencapsulated particles. Overall, the supercritical encapsulation process for the natural extract of olive pruning residues has proven to be effective in obtaining antioxidant particles with different release profiles.

Vancomycin-loaded methylcellulose aerogel scaffolds for advanced bone tissue engineering

Scaffolds grafting combined with local delivery of antibiotics at the injury site may promote bone regeneration along with prevention of infections. In this work, a processing strategy combining the 3D-printing of polysaccharide-based inks with supercritical (sc)CO2 technology was employed to manufacture drug-loaded, nanostructured, and personalized-to-patient aerogels for the first time. Methylcellulose (MC) was employed as graft matrix endowed with nanohydroxyapatite (nHA) to confer bioactivity as required in bone tissue engineering (BTE). MC-nHA aerogels were obtained through the 3D-printing of hydrogel-based scaffolds followed by scCO2 drying. Aerogels were loaded with vancomycin (VAN), an antibiotic employed in the management of bone infections. Textural properties and printing fidelity of scaffolds were studied as well as VAN release, long-term bioactivity, and pre-osteoblasts mineralization. In vitro cell studies and in vivo Artemia salina tests were carried out to evaluate the potential toxicity of the antibiotic-loaded aerogels. Aerogels efficacy in inhibiting bacterial growth was assessed by antimicrobial tests with Staphylococcus aureus. Textural stability of the aerogels after 7 months of storage was also evaluated. Obtained results showed that the scaffolds promoted the intended two-in-one effect (bone repair and infection management simultaneously) in a personalized way, regulating formulation design, drug dose, and porosity.

Scalable production of polyamide-6/graphene composites with enhanced electromagnetic shielding and thermal conductivity

Composites with thermal management (TM) capability and electromagnetic interference (EMI) shielding effect are in high demand for miniaturization and modernization of electronics. However, achieving both of these properties simultaneously by constructing a dense conductive network within the polymer matrix is a very big challenge. Herein, a fully scalable and sustainable production process for polyamide-6/few layer graphene (PA-6/FLG) with vigorous dispersion of FLG in the PA-6 matrix was demonstrated by combining mechanochemistry with supercritical CO2 (scCO2) technology. By this process, the bulk graphite was rapidly cleaved into a FLG (≈10 layers), which was completely coated onto the spherical PA-6 particles. The composite films of this coated powder with only 3 wt% FLG loading amount attained wonderful in-plane electrical conductivity (IP-σc) and through-plane electrical conductivity (TP-σc) of 4.59 S·m−1 and 29.59 S·m−1, respectively, and outstanding EMI shielding effect of 41.8 dBs. In addition, the in-plane thermal conductivity (IP- kc) and the through-plane thermal conductivity (TP- kc) were 1.78 W m−1 K−1 and 2.14 W m−1 K−1 respectively. Therefore, the films rapidly dissipate heat from an electronic LED chip. Moreover, PA-6/FLG composite filaments showed a smooth appearance and an electrical resistivity of 7.12 GΩ. This work has strong potential to improve the performance of different polymer/graphene composites and expand their applications.

Preparation of chitin/MXene/poly(L-arginine) composite aerogel spheres for specific adsorption of bilirubin

Currently, hemoperfusion is clinically the most rapid and effective treatment for removing toxins from the blood. The core of hemoperfusion is the sorbent inside the hemoperfusion device. Due to the complex composition of the blood, adsorbents tend to adsorb substances such as proteins in the blood (non-specific adsorption) while adsorbing toxins. Hyperbilirubinemia is caused by excessive levels of bilirubin in the human blood, causing irreversible damage to the patient's brain and nervous system, and even leading to death. High adsorption and high biocompatibility adsorbents with specific bilirubin adsorption are urgently needed to treat hyperbilirubinemia. Herein, poly(L-arginine) (PLA) which can specifically adsorb bilirubin, was introduced into chitin/MXene (Ch/MX) composite aerogel spheres. Ch/MX/PLA prepared by supercritical CO2 technology had higher mechanical properties than Ch/MX and can withstand 50,000 times its own weight. The in vitro simulated hemoperfusion test showed that the adsorption capacity of Ch/MX/PLA was as high as 596.31 mg/g, which was 15.38 % higher than that of Ch/MX. Binary and ternary competitive adsorption tests showed that Ch/MX/PLA also had good adsorption capacity in the presence of a variety of interfering molecules. In addition, hemolysis rate testing and CCK-8 testing confirmed that Ch/MX/PLA had better biocompatibility and hemocompatibility. Ch/MX/PLA can meet the required properties of clinical hemoperfusion sorbents and has the ability to produce mass production. It has good application potential in the clinical treatment of hyperbilirubinemia.

High-intensity ultrasound-based process strategies for obtaining edible sunflower (Helianthus annuus L.) flour with low-phenolic and high-protein content

The sunflower Helianthus annuus L. represents the 4th largest oilseed cultivated area worldwide. Its balanced amino acid content and low content of antinutrient factors give sunflower protein a good nutritional value. However, it is underexploited as a supplement to human nutrition due to the high content of phenolic compounds that reduce the sensory quality of the product. Thus, this study aimed at obtaining a high protein and low phenolic compound sunflower flour for use in the food industry by designing separation processes with high intensity ultrasound technology. First, sunflower meal, a residue of cold-press oil extraction processing, was defatted using supercritical CO2 technology. Subsequently, sunflower meal was subjected to different conditions for ultrasound-assisted extraction of phenolic compounds. The effects of solvent composition (water: ethanol) and pH (4 to 12) were investigated using different acoustic energies and continuous and pulsed process approaches. The employed process strategies reduced the oil content of sunflower meal by up to 90% and reduced 83% of the phenolic content. Furthermore, the protein content of sunflower flour was increased up to approximately 72% with respect to sunflower meal. The acoustic cavitation-based processes using the optimized solvent composition were efficient in breaking down the cellular structure of the plant matrix and facilitated the separation of proteins and phenolic compounds, while preserving the functional groups of the product. Therefore, a new ingredient with high protein content and potential application for human food was obtained from the residue of sunflower oil processing using green technologies.

Overcrowded Additive in Electrolyte and Crystalline Li2CO3 Artificial Solid Electrolyte Interphase on TiNb2O7 Anode Enable Long Lifespan Aqueous Lithium-Ion Batteries

Aqueous lithium-ion batteries (ALIBs) are attracting intense attention because of the intrinsic nonflammable nature of the aqueous electrolytes. However, its own narrow electrochemical window has led to numerous problems such as dissolution of electrode materials, hydrogen evolution at the anode, and poor cycling stability. Here, we report an “overcrowded electrolyte” using 1,4-dioxane as an additive, which has lone pairs of electrons on the oxygen atom to disrupt the original water-hydrogen bonding network by forming intermolecular hydrogen bonds, thereby inhibiting the hydrogen evolution reaction (HER) and decreasing the water activity. Furthermore, a layer of crystalline Li2CO3 is coated onto the surface of the TiNb2O7 anode material by supercritical fluid CO2 technology. The dense hydrophobic Li2CO3 coating layer can serve as a physical protection, which effectively blocks the direct contact between electrolyte and electrode. Under the synergistic effect of those two aspects, HER is greatly suppressed and the interface stability is enhanced. As a result, LiMn2O4/TiNb2O7 full cells exhibit a high initial coulomb efficiency of 95% with a capacity retention rate of 92% over 500 cycles under 1 C rate. This work provides a fundamental understanding of the interfacial chemistry of ALIBs and makes an important step forward in the development of high-performance and low-cost ALIBs for practical applications.

Efficient purification of surface modified nanoparticles from its nanosuspension by using supercritical CO2 technology

In applications of surface-modified nanoparticles (NPs), simple and complete washing technology without using an organic solvent and drying technique to realize good re-dispersity have been desired. In this study, we report washing and drying strategy using supercritical CO2 (scCO2) and applied it to the nanosuspension including decanoic acid modified Fe3O4 NPs and decanoic acid to be removed. Notably, scCO2 gave the removal efficiency of decanoic acid over 99 %, almost complete washing, which can be explained by its high diffusibility. Additionally, compared to traditional heat evaporation, the re-dispersity of NPs in hexane was significantly improved for scCO2 drying that allows the disappearance of gas-liquid interface. These results conclusively show that washing and drying technology using scCO2, with the characteristics of high diffusibility and no interface, can be an appealing approach to realize simple and complete purification of surface modified NPs with good re-dispersity.

An ultra-high disulfiram-loaded delivery system achieved by supercritical carbon dioxide technology for copper-enhanced chemotherapy

Disulfiram (DSF) is a conventional alcohol-aversion drug that has recently been explored as a chemotherapeutic agent and has shown excellent anticancer activity in cooperation with Cu2+ ions. However, the existing DSF delivery system has multiple shortcomings, including low drug loading and Cu2+ delivery efficiency, hindering its clinical applicability. Here, we demonstrated a simple but efficient strategy for realizing the controllable loading of hydrophobic DSF into Cu2+-doped mesoporous silica nanoparticles (Cu-MSN) by using supercritical CO2 technology with ultra-high drug loading efficiency. Benefiting from the unique environment of high pressure and solubility, DSF was well dispersed in supercritical CO2 and immersed into the carriers with controllable drug loading. Factorial experiments indicated an optimal condition (55 °C, 250 bar, and 6 h) for the DSF loading up to 30.8 %. In vitro and in vivo experiments demonstrated high Cu2+-enhanced chemotherapeutic efficacy of DSF. In particular, in cooperation with Cu2+ ions in MSN, the formation of complex (CuET) greatly enhanced and prolonged the antitumor effect. Together, our findings indicated that DSF-loaded Cu-MSN prepared using supercritical solvent impregnation (SSI) enhanced the antitumor effect and had potential in anticancer therapy.

Increasing solubility of phenytoin and raloxifene drugs: Application of supercritical CO2 technology

In the present investigation, the solubility of two drugs i.e., phenytoin and raloxifene, was obtained in supercritical CO2 at various temperatures and pressures. The obtained results were shown that the solubility of phenytoin and raloxifene, based on mole fraction, was between 0.68 × 10−6 to 15.70 × 10−6 and 0.79 × 10−5 to 8.09 × 10−5, respectively. The experimental solubilities data shown the direct influence of pressure on them; nevertheless, the extraction temperature had a different effect. Besides, two mathematical approaches based on thermodynamic models were used to model the phenytoin and raloxifene experimental results. Indeed, solubilities data were predicted using Peng-Robinson equations of state (PR EoS) in conjunction with three famous mixing rules i.e., Kwak-Mansoori (KM) and van der Waals (vdW) type I and II. The obtained results demonstrated the Peng-Robinson equations of state with the Kwak-Mansoori mixing rule predicted the solubilities of phenytoin and raloxifene drugs with more accuracy, especially at higher pressures (in order with an average percent deviation equal to 6.2282 and 5.5715, respectively). Moreover, three density-based correlations, as semi-empirical models, i.e., Garlapati and Madras, Bartle et al. and Mendez-Santiago Teja correlations, were used to model the phenytoin and raloxifene solubilities data. For both drugs, Bartle et al. model showed better performance.

Anti-inflammatory effect of two pomegranate seed oils obtained by green technologies in Caco-2 cells using the bioaccessible fraction from in vitro gastrointestinal digestion

Pomegranate seeds contain up to 20% oil with a high content of punicic acid (85%), which is responsible for several biological activities. In this work, two pomegranate oils obtained by a two-step sequential extraction, first with an expeller and then via supercritical CO2 technologies, have been studied in a static gastrointestinal in vitro digestion model to evaluate their bioaccessibility. The micellar phases obtained were evaluated by an in vitro model of intestinal inflammation and Caco-2 cells exposed to the inflammatory mediator lipopolysaccharide (LPS). Inflammatory response was assessed by measuring the production of interleukins IL-6 and IL-8, and tumor necrosis factor α (TNF-α), and by evaluating the monolayer integrity. The results obtained indicate that expeller pomegranate oil (EPO) provides the highest amount of micellar phase (ca. 93%) with free fatty acids and monoacylglycerols as major components. The micellar phase obtained with supercritical CO2 pomegranate oil (SCPO) is ca. 82% with similar lipid composition. Micellar phases of EPO and SCPO showed high stability and adequate particle size. EPO shows an anti-inflammatory response, reducing the production of IL-6, IL-8 and TNF-α in LPS stimulated caco-2 cells and increasing the integrity of the cell monolayer as measured by transepithelial electrical resistance (TEER). In the case of SCPO, the anti-inflammatory effect was only evident for IL-8. The present work demonstrates good digestibility, bioaccessibility and anti-inflammatory response of both EPO and SCPO oils.

Chemical characterization of pomegranate and alfalfa seed oils obtained by a two-step sequential extraction procedure of expeller and supercritical CO2 technologies

A combination of two green extraction technologies, i.e., expeller and supercritical CO2, have been applied in a sequential two-step methodology for the extraction of pomegranate and alfalfa seed oils, considering material valorization and environmental sustainability. High yields of oil extraction have been obtained for pomegranate (77.2%) and alfalfa (94.6%) seeds, and press cakes and defatted flours have been produced. The procedures do not require refining and the properties of the oils are found to be superior in terms of valuable minor compounds. A thorough chemical characterization of the extracted oils has also been carried out to demonstrate the high quality of the extracted seed oils. Unexpected positional distributions of some fatty acids have been found in pomegranate seed oil, such as sn-1,3 position in punicic acid. New chemical findings have been described for alfalfa oil for the first time, such as considerable levels of squalene (1.03 g/100 g) and the sn-1,3 positional distribution in α-linolenic acid. Moreover, phosphatidylinositol is the main phospholipid found and the oxidative values are shown to be within the standard limits.

Selective Supercritical CO2 Extraction and Biocatalytic Valorization of Cucurbita pepo L. Industrial Residuals.

The valorization of biomass residuals constitutes a key aspect of circular economy and thus a major challenge for the scientific community. Among industrial wastes, plant residuals could represent an attractive source of bioactive compounds. In this context, a residue from the industrial extraction of Cucurbita pepo L. seeds, whose oil is commercialized for the treatment of genito-urinary tract pathologies, has been selected. Supercritical CO2 technology has been employed as a highly selective “green” methodology allowing the recovery of compounds without chemical degradation and limited operational costs. Free fatty acids have been collected in mild conditions while an enrichment in sterols has been selectively obtained from sc-CO2 extracts by appropriate modulation of process parameters (supercritical fluid pressure and temperature), hence demonstrating the feasibility of the technique to target added-value compounds in a selective way. Obtained fatty acids were thus converted into the corresponding ethanol carboxamide derivatives by lipase-mediated biocatalyzed reactions, while the hydroxylated derivatives of unsaturated fatty acids were obtained by stereoselective hydration reaction under reductive conditions in the presence of a selected FADH2-dependent oleate hydratase.

Exfoliation of Active Materials Synchronized with Electrolyte Extraction from Spent Lithium‐Ion Batteries by Supercritical CO2

AbstractSafe and harmless treatment of electrolyte is a critical environment issue for spent lithium‐ion battery recycling; the effective separation of cathode materials from aluminum foil is a key technology for resource utilization. Previous studies have never considered the two as a whole. This study introduced supercritical CO2 technology to realize the integrated treatment of electrolyte removal and cathode material exfoliation. The results indicated that the optimum parameter was obtained at a temperature of 38 °C, a time of 15 min and a pressure of 10 MPa. The peeling efficiency of cathode material from Al foil reached 98.86 wt.%. Mechanism analysis confirmed that the separation of Al foil and cathode material was the result of the weakened adhesion of electrode interface, which can be attributed to the removal of the organic component including carbonate‐based organic solution and organic binder caused by the fluid extraction process.

Co-precipitation of grape residue extract using sub- and supercritical CO2 technology

In this work, the co-precipitation of ethanol extract from grape residue with a biodegradable and biocompatible polymer, polyvinylpyrrolidone, was studied using sub- and supercritical carbon dioxide (CO2) technology, namely in the present work by pressurized anti-solvent (PAS). A full design was used to evaluate the effect of pressure (90, 130 and 170 bar) and temperature (20, 32 and 45 ºC) on the PAS process and the characteristics of the particles formed by it. The particles obtained from the best PAS conditions were submitted to in vitro release studies. Higher pressures and temperatures (CO2 in supercritical state) significantly resulted in operational conditions with better global precipitation yields and in the production of particles with a lower average diameter and residual ethanol content. The particles had a quasi-spherical shape connected to each other with sizes ranging from 1.3 to 4.1 µm. The interaction of low temperature with high pressure (CO2 in subcritical state) led to the production of dry powders more concentrated in anthocyanins and total phenolic compounds, and in processes with higher co-precipitation yields of these bioactives. From the in vitro release tests, it was observed that the microparticles released more slowly anthocyanins in simulated gastrointestinal fluids than the precipitated extract without polymer. In the end, it can be concluded that the PAS technique is a very promising process for co-precipitating and concentrating sensitive polar compounds present in crude plant extracts, and produce bioactive microparticles with interesting physicochemical characteristics. Furthermore, it leads to the production bioactive delivery systems with better dissolution rates in simulated gastrointestinal fluids, thus showing potential to be applied in areas that work in favor of health and human well-being.

Supercritical Carbon Dioxide Decellularized Xenograft-3D CAD/CAM Carved Bone Matrix Personalized for Human Bone Defect Repair.

About 30–50% of oral cancer patients require mandibulectomy and autologous fibula reconstruction. Autograft is the gold standard choice because of its histocompatibility; however, it requires additional surgery from the patient and with possible complications such as loss of fibula leading to calf weakening in the future. Allograft and xenograft are alternatives but are susceptible to immune response. Currently, no personalized bone xenografts are available in the market for large fascial bone defects. In addition, a large-sized complex shape bone graft cannot be produced directly from the raw material. We propose the use of porcine bones with 3D CAD/CAM carving to reconstruct a personalized, wide range and complex-shaped bone. We anticipate that patients can restore their native facial appearance after reconstruction surgery. Supercritical CO2 (SCCO2) technology was employed to remove the cells, fat and non-collagenous materials while maintaining a native collagen scaffold as a biomedical device for bone defects. We successfully developed 3D CAD/CAM carved bone matrices, followed by SCCO2 decellularization of those large-sized bones. A lock-and-key puzzle design was employed to fulfil a wide range of large and complex-shaped maxillofacial defects. To conclude, the 3D CAD/CAM carved bone matrices with lock and key puzzle Lego design were completely decellularized by SCCO2 extraction technology with intact natural collagen scaffold. In addition, the processed bone matrices were tested to show excellent cytocompatibility and mechanical stiffness. Thus, we can overcome the limitation of large size and complex shapes of xenograft availability. In addition, the 3D CAD/CAM carving process can provide personalized tailor-designed decellularized bone grafts for the native appearance for maxillofacial reconstruction surgery for oral cancer patients and trauma patients.

Meso/microporous MOF@graphene oxide composite aerogels prepared by generic supercritical CO2 technology

The increasing complexity in composition and structure of modern porous nanocomposite materials requires the development of advanced technologies that allow the simultaneous treatment of dissimilar compounds, not only with unlike composition but also involving different classes of pores, e.g., micro and mesopores. This work shows that supercritical CO 2 (scCO 2 ) technology can be used as generic processing aid to obtain composites involving non-reduced graphene oxide (GO) and metal organic frameworks (MOFs) in the form of aerogels with hierarchical porosity. Hybrid aerogels are formed by either depositing ( ex situ ) or growing ( in situ ) MOF nanocrystals onto the surface of 2D GO nanosheets. The archetypal hydrophilic HKUST-1 and UiO-66 and hydrophobic ZIF-8 microporous MOFs are chosen to exemplify the method possibilities. The ex situ route was adequate to prepare hydrophilic MOFs@GO homogeneous composites, while the in situ approach must be used to prepare hydrophobic MOFs@GO aerogels. Moreover, the scCO 2 methodology should be adjusted for each studied MOF in regard of the organic solvent used to disperse the nanoentities constituting the composite. The end-products are obtained in the form of aerogels mimicking the shape of the recipient in which they are contained. The products are characterized in regard of structure by X-ray diffraction, textural properties by low temperature N 2 adsorption/desorption and morphology by electronic microscopy. • scCO 2 as a synthetic platform for fabrication of meso/microporous MOF@GO aerogels. • MOF hydrophobic/hydrophilic nature defines the choice of ex situ/in situ scCO 2 method. • The ex situ route can be applied to a large number of MOFs with hydrophilic nature. • The in situ method can be also applied to hydrophobic MOFs to reduce time/resources. • MOF@GO composites were homogenous with hierarchical micro/meso porosity.