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Heterostructure engineering of electrocatalysts provides a fascinating platform to reasonably manipulate the physicochemical properties of nanomaterials and further improve their catalytic efficiency for water electrolysis. However, it still remains a huge challenge to construct well-designed core-shell heterostructured catalysts and identify the key role of components for synergistic catalysis. Herein, a melted polymeric salt tactics was innovatively developed to synthesize heterostructured Ni@Ni(OH)2 core-shell nanomaterials supported on porous carbon (named Ni@Ni(OH)2/PC), wherein well-defined Ni(OH)2-Ni heterostructure plays a pivotal role in improving electrocatalytic activity for water reduction and oxidation. Besides, the stable porous carbon support functions as a highway for continuous electron transfer between Ni and Ni(OH)2, and simultaneously enables the full exposure of accessible active sites. The fabricated Ni@Ni(OH)2/PC exhibits outstanding bifunctional electrocatalytic performance for overall water splitting (ƞ10 = 1.55 V) with a good long-time stability. This work sheds new light on the design of engineering heterostructure of active bifunctional electrocatalysts for efficient energy conversion system.

The surface of highly porous carbon black, Black Pearl 2000, was modified with urea and thiourea to introduce only N- or N- and S-containing functional groups. They enhanced its activity in the oxygen reduction reaction.

The trends in the value and shift of a water melting point in nanoporous carbons of distinctive surface chemistry were analyzed. The carbons were obtained from sulfur containing polymers and they were additionally exposed to H2S at high temperature to introduce specific thiophenic/bisulfides of hydrophobic character. The carbons surface chemistry and porosity were evaluated by XPS, potentiometric titration, thermal analysis and adsorption of nitrogen. The behavior of water was tested using dielectric and tensiometric methods. While carbons had similar sizes of pores, their chemistry differed. The initial carbons were more acidic and more hydrophilic than those H2S treated. The treatment markedly reduced the surface functionalities from the view point of their chemical character and amount on the surface. As expected for carbon materials, the melting point of water decreased compared to that in the bulk owing to stronger fluid-fluid interactions than those of fluid-walls. Nevertheless, that decrease was smaller for carbons of most acidic surface and thus for those attracting water than for carbons of hydrophobic surface. That apparent discrepancy suggested that roughness, seen in the values of the contact angle and wetting energy, affects melting point more than the low affinity of hydrophobic surface groups to attract water.

The 17th International Conference on Chemistry and the Environment (ICCE 2019) took place in the period 16–20 June 2019, in Thessaloniki, Greece. The Conference Centre of the Aristotle University of Thessaloniki, named KEDEA, was chosen as an appropriate venue for the conference. Through its lecture halls, foyer for posters and exhibition stands, food, and refreshment facilities, it offered a great conference environment. We appreciate the help of all people involved in the efficient and smooth organization (Organizing Committee, University personnel, Students) of ICCE 2019. The ICCE has been organized since 1980 by the Division of Chemistry and the Environment (DCE) of the European Chemical Society (EuChemS) as a biennial conference. The first meeting took place in Paris.

Porous carbons were obtained from rice husk using two different chemical activation methods and they were investigated as supercapacitors. Their properties were studied using X-ray photoelectron spectroscopy, thermal analysis, potentiometric titration, and nitrogen adsorption isotherm. The specific capacitance measured in both H2SO4 and KOH electrolytes in two-electrode cell was up to ~150 F/g. The activation method used affected the resulting carbons' features. As expected, the dependence of the capacitance on porosity was found. The ash content reached 36 wt.% and that inorganic mater blocked some pores and limited their accessibility to electrolyte ions and increased the charge transfer resistance. Nevertheless, the main ash constituents such as CaCO3, MgCO3, Ca3(PO4)2 (or P2O5), and Fe- and Zn- containing species did not affect the specific capacitance to a large extent. Especially SiO2, even in a relatively large amount (~20 wt.%), did not play a detrimental role in the capacitance behavior. The results showed that in spite of a high ash content, carbon can exhibit a good capacitive performance provided that it has a favorable porosity and is rich in sp2 configurations.

For proper and fair comparison of the performance of Oxygen reduction reaction (ORR) electrocatalysts an un-biased method to determine an onset potential value is needed. Here we report an easy mathematical approach based on the second derivative of linear sweep voltammetry curves, referred to as a second order discrete differentiation method (SODDM) that allows to accurately provide the onset potential. Analysis of the published results showed that the reported values might be affected by an intrinsic human error associated with the application of the most common approaches addressed as a tangent method or those relaying on a visual estimation of the onset potential based on the shape of a linear scan voltammetry (LSV) curve. We have also demonstrated that by using SODDM, electrochemical data collected on different instruments by different researchers leads to comparable results in terms of the ORR onset potential values.

Gas-phase desulfurization on carbon materials is an important process attracting the attention of scientists and engineers. When involving physical adsorption, reactive adsorption and catalytic oxidation combined, the process is considered as energy-efficient. Recent developments in materials science directed the attention of researchers to inorganic phases which react with H

Wood-, coal-, and coconut-based activated carbons and ordered mesoporous silica (SBA-15) were selected as supports to synthesize bifunctional ZnFe2O4 adsorbents for an H2S removal from air under ambient conditions. The effects of supports on active phase nanoparticle features and on the efficiency of the H2S removal were investigated. The collected results showed the differences in the composition, morphology and dispersion of the active phase. The carbon supports demonstrated superiority over SBA-15 owing to their electron-rich matrix, abundance of surface defects and the ability to catalyze H2S oxidation. In the case of silica, strong interactions between ZnFe2O4 and SBA-15 leading to the formation of Me–O–Si (Me=Zn, Fe) bonds inactivated metal ions, which was demonstrated in an inferior performance in the H2S removal. The results also indicated that the differences in the graphitization degree, microporosity, and surface pH of the carbon supports result in remarkable differences in the adsorbents efficiency for the H2S removal. This study provides new insights for the rational fabrication of efficient metal oxides-based adsorbents and for a full utilization of their reactive adsorption capability in a nanoscale range.

Polymer-derived porous carbon was used as a support of iron and nickel species with an objective to obtain an efficient oxygen reduction reaction (OER) catalyst. The surface features were extensively characterized using X-ray diffraction, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. On FeNi-modified carbon the overpotential for OER was very low (280 mV) and comparable to that on noble metal catalyst IrO2. The electrochemical properties have been investigated to reveal the difference between the binary alloy- and single metal-doped carbons. This work demonstrates a significant step for the development of low-cost, environmentally-friendly and highly-efficient OER catalysts.

Oxygen Reduction Reaction (ORR) catalysts were synthesized from biosolids by simple pyrolysis at 950 °C. Their surface features were modified by changing pyrolysis conditions (ramp and holding time). The obtained materials, after an extensive surface characterization, were tested as ORR catalysts in an alkaline medium. They exhibited a high catalytic activity with the number of electron transfer close to 4 (3.99) and a kinetic current density of 8 mA cm−2. Their excellent performance was linked to the hierarchical porosity, high integrity of the carbon phase of an enhanced graphitization degree, and to the presence of catalytic centers. The samples prepared at a long pyrolysis time were very active in the ORR due to the developed micropores and the high graphitization degree of the carbon phase. Mild acid washing decreased the number of electron transfer by removing metal-based catalytic centers and by negatively affecting the integrity of the carbon phase covering the pore walls.

Metal-free nanoporous carbons, either as received or sulfur doped, have been studied as photocatalysts for the degradation of phenol under solar light irradiation. The introduction of sulfur significantly enhanced both phenol adsorption and photodegradation. The texture and surface chemistry of the catalysts tested were evaluated using adsorption of nitrogen, thermal analysis, potentiometric titration and XPS. Various parameters related to the kinetics of phenol adsorption and photodegradation were investigated. They include the kinetics order for the adsorption and the intraparticle diffusion coefficient. The effect of the surface density of the molecules adsorbed on the efficiency of photodegradation was also evaluated. The photocatalytic activity for the degradation of phenol in terms of the distribution of main intermediate products was linked to the type and content of S-containing functional groups. It was found that thiophenic groups in small pores enhance phenol adsorption via providing basicity and hydrophobicity and contribute to photoactivity by inducing defects altering the energy band gap. Sulfoxides and sulfone, on the other hand, increase the selectivity of phenol oxidation to catechol and participate to oxidation via increasing the population of holes, which might promote the formation of reactive sulfur and oxygen species.

Nanocomposites and hybrid materials of Ag-1,3,5- benzenetricarboxylic acid metal-organic frameworks (MOFs) with Sand N-carbon quantum dots (CQDs) were synthesized and evaluated for their antibacterial activity against representative Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial strains using the qualitative disk-diffusion approach and the quantitative minimum inhibitory concentration test. The composites and hybrids were found to be nontoxic to living cells. The composite formation fostered a synergistic effect that enhanced their antibacterial activity compared with those of their pristine components. Charge transfer from AgMOF to CQDs facilitated the electrostatic interactions of the composites and hybrids with the bacterial cell membranes. Enhanced bactericidal activity was linked to morphological features (a nanorod-like morphology) and specific surface chemistry. The latter affected the release of silver. Silver on the surface of the MOFs rather than silver in the bulk was found to be important. The destruction of the MOF component in the extracellular environment led to the release of silver ions, which have a high affinity to S compounds of the cell physiology. The formation of metallic silver (Ago) and silver sulfides (Ag2S) was suggested as essential for the ability of the composites and hybrids to inhibit bacterial growth. To the best of our knowledge, this is the first study that introduces the bactericidal effect of AgMOF-CQDs composites and hybrids. Fil: Travlou, Nikolina A.. City University of New York; Estados Unidos Fil: Algarra, Manuel. Universidad de Málaga; España Fil: Alcoholado, Cristina. Universidad de Málaga; España. Consejo Superior de Investigaciones Científicas. Centro de Investigaciones Biológicas; España Fil: Cifuentes Rueda, Manuel. Universidad de Málaga; España. Consejo Superior de Investigaciones Científicas. Centro de Investigaciones Biológicas; España Fil: Labella, Alejandro M.. Universidad de Málaga; España Fil: Lazaro Martinez, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Rodríguez Castellón, Enrique. Universidad de Málaga; España Fil: Bandosz, Teresa J.. City University of New York; Estados Unidos

Carbon dots (CDs) and N-carbon dots (N-CDs) loaded with Ru-complex (CDs@RuCN, N-CDs@RuCN, respectively) were investigated as media imposing biochemical changes induced by UV illumination of ovarian cancer, A2780, and osteosarcoma, CAL72, cells. Synchrotron radiation-based Fourier Transform Infrared Spectroscopy was performed, and the spectra were subjected to a Principal Component Analysis. The CDs@RuCN and N-CDs@RuCN effects on cancer cells were analyzed by the theoretical modelling of the stability of the composite systems and a protein database search. Moreover, a detailed evaluation of surface and optical properties of CDs@RuCN and N-CDs@RuCN was carried out. Results demonstrated selective action of the CDs@RuCN and N-CDs@RuCN-based photodynamic therapy, with N-CDs@RuCN being the most active in inducing changes in A2780 and CDs@RuCN in CAL72 cells. We assume that different surface charges of nanoparticles led to direct interactions of N-CDs@RuCN with a Wnt signalling pathway in A2780 and those of CDs@RuCN with PI3–K/Akt in CAL72 cells and that further biochemical changes occurred upon light illumination.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a class of fluorinated aliphatic compounds considered as emerging persistent pollutants. Owing to their adverse effects on human health and environment, efficient methods of their removal from various complex matrices need to be developed. This review focuses on recent results addressing the adsorption of PFAS on activated carbons (AC) and metal-organic frameworks (MOF). While the former are well-established adsorbents used in water treatment, the latter are relatively new and still not applied at a large scale. Nevertheless, they attract research interests owing to their developed porosity and versatile surface chemistry. While AC provide high volumes of pores and hydrophobic surfaces to strongly attract fluorinated chains, MOF supply sites for acid-base complexation and a variety of specific interactions. The modifications of AC are focused on the introduction of basicity to attract PFAS anions via electrostatic/chemical interactions, and those of MOF - on structural defects to increase the pore sizes. Based on the comparison of the performance and specifically adsorption forces provided by these two groups of materials, activated carbons were pointed out as worthy of further research efforts. This is because their surface, especially that in large pores, where dispersive forces are week and where extensive pore space might be utilized to adsorb more PFAS, can be further chemically modified and these modifications might be informed by the mechanisms of PFAS adsorption, which are specific for MOF. This review emphasizes the effects of these modifications on the adsorption mechanism and brings the critical assessment of the advantages/disadvantages of both groups as PFAS adsorbents.

Carbonaceous porous adsorbents of a high content of an inorganic phase (40–80%) were prepared by the zinc chloride activation of waste bio-char from the liquefication of pig manure at 900 °C. To increase both the content of the carbon phase and conductivity 10% nanographite was added to bio-char before the carbonization/activation process. Even though no strong effect of a char/activation agent ratio on the materials' porosity was found, they slightly differ in the surface areas and in the contents of the inorganic phase, which was found to be rich in calcium and magnesium. The synthesized materials were used as formaldehyde adsorbents from its low concentration of ∼2 ppm. The measured breakthrough capacity reached 0.78 mg/g and was higher than those measured on commercial carbons of high porosities. Since upon exposure to formaldehyde a marked surface acidification was found, the good performance of the composite adsorbents was linked not only to the porosity of the carbon phase but also to the effect of an alkaline environment in mesopores and to that of transition metals oxides on formaldehyde oxidation to formic acid. That acid likely formed salts with alkaline and alkaline earth metals present in our adsorbents. There was an indication that nanographite increased the extent of the formaldehyde oxidation reaction, which was demonstrated in a marked decrease in the surface pH of the spent adsorbent with the moderate amount of formaldehyde adsorbed.

With an objective to increase an electrochemical performance, simple and effective modifications of activated carbon fiber textiles (ACT) were carried out prior to their testing as supercapacitors. The modifications included a high-temperature treatment of the textile impregnated with N- and S-containing species (i.e. dicyandiamide, urea and thiourea). This led to an improvement in an electrical conductivity and in an enhanced mechanical strength with a preserved porosity. Compared to the performance of the initial unmodified carbon textile, a urea-functionalized material showed an enhancement in the electrochemical capacitance. An increase from 177 to 209 F g−1 at a scan rate 10 mV s−1 in an alkaline electrolyte was recorded (3-cell CV measurements) and from 138 to 166 F g−1 at 0.10 A g−1 (2-cell galvanostatic charge-discharge). The results suggested that mechanically stable, flexible and conductive ACT have a potential to be used in textile-based flexible supercapacitors. Benefits coming from the applied modification routes can be also adapted for the fabrication of other types of carbon-based composite electrode materials.

Electrical response of nanoporous carbon upon exposure to VOCs was tested. For this purpose, commercial wood-based chemically activated carbon was chosen owing to its high surface area, heterogeneity of its pore sizes and rich surface chemistry. When carbon chips were exposed to various concentrations of toluene, chloroform, and methanol vapors visible changes in resistivity were observed and these changes were linked to the properties of the adsorbates and the extent of an adsorption process. The findings support the feasibility of both: adsorption-based VOCs sensing and electrical response-based adsorption measurements on porous carbons.

Four porous activated carbon textiles have been evaluated as protective media against 2-chloroethyl ethyl sulfide (CEES) vapors, a surrogate of the chemical warfare agent Mustard gas. In contrast to other results reported in the literature which have been collected in solutions, our experiments were conducted from a vapor phase in ambient air and these conditions resemble those of CWA potential applications. Besides the determination of the maximum adsorption capability, the adsorption/interaction strength was also evaluated based on desorption tests. The tested textiles were able to adsorb marked amounts of CEES (up to 324 mg/g). The desorption extent, more than that of adsorption, was controlled by the microporosity and chemical composition of the surface; however, the involved factors were found as very complex. The analysis of the headspace of the adsorption system and of the surface of the samples after exposure to CEES revealed that the studied textiles were also able to degrade the CEES molecules to less toxic compounds. The obtained results showed that porous carbon textiles can act not only as high-capacity adsorbents of toxic vapors but also as catalysts for their degradation.

Modified graphite oxide (ΝGO) was used as a support of a manganese oxide of hausmannite type (Mn3O4) nanocatalyst and applied for the degradation of an endocrine disruptor, bisphenol-A (BPA). The prepared nanocomposite/catalyst (NGO-Mn3O4), as well as pure modified graphite oxide and manganese oxide, were characterized by X-ray diffraction, Scanning Electron Microscopy, nitrogen adsorption, X-ray photoelectron spectroscopy, Fourier Transform Infrared Spectroscopy, and potentiometric titration. The maximum removal activity for all the materials was measured at pH = 3. The NGO-Mn3O4 nanocomposite showed the highest removal efficiency of BPA at an ambient temperature without light irradiation and/or the addition of chemicals, which can be attributed to the synergistic effect of the composite formation. The nanocomposite exhibited a high catalytic activity for the degradation/oxidation of BPA, which was dramatically higher than that of the pristine Mn3O4 phase. Modified graphite oxide showed also an enhanced capability for the BPA removal, which was linked to an increased physical adsorption component.

Highly porous (specific surface area, SBET, 1400 m2/g) and rich in surface groups activated carbons (ACs) were obtained from cotton stalks using either a direct or indirect activation. They were characterized by adsorption of nitrogen, thermal analysis combined with mass spectrometry, potentiometric titration, and X-ray photoelectron spectroscopy (XPS). XPS analysis indicated that the indirect activation led to more nitrogen on the surface incorporated as pyridinic and graphitic/quaternary species. These species were beneficial for a carbon application as oxygen reduction reaction (ORR) electrocatalysts and supercapacitors. The carbons were catalytically active in ORR with a number of electron transfer from 2.15 to 3.40 and onset potential of 0.810 V vs. reference hydrogen electrode (RHE). Their capacitance was around 180 F g−1 at 1 A g−1 when measured in an alkaline medium. The dependence of the performance on the porosity and nitrogen content was found, indicating suitability of cotton stalks obtained using the indirect activation as precursors of carbons of promising electrochemically active features.

Barium titanate nanoparticles (BTO-NPs) in the size range 8-12 nm, prepared by gel collection, are found to be a photoreactive detoxifier for Chemical Warfare Agent vapors, specifically, the sulfur mustard surrogate (2-chloroethyl ethyl sulfide). The relatively monodisperse, uniformly spherical BTO-NPs, initially dispersed in alcohol solvents, form a stable and porous aggregated structure reminiscent of a nanostructured material with voids/pores of an average diameter of 4.6 nm and a relatively narrow distribution of their sizes (2.5-8.7 nm). Due to the interparticle porosity and a polar, chemically active surface, signifcant amounts of CWA surrogate and its decomposition products were adsorbed on the BTO-NPs. The recorded weight uptake on the perovskite was the highest among a series of materials and nanocomposites known for their detoxification activity and tested at the same conditions (169 mg/g, compared to 117 mg/g for zinc oxide and100 mg/g for other transition metal oxides). Besides adsorption, BTO nanomaterial acts simultaneously as an efficient heterogeneous catalyst by degrading the toxic vapors to alcohols, sulfides and thiols - molecules of significantly lower toxicity than the CWA surrogate. Hydrolysis and dehydrohalogenation were the predominant detoxification pathways, via the formation of the intermediate cyclic sulfonium, whether under light or in the dark. Ambient light irradiation promoted the photo-oxidation and photo-degradation by radical intermediates formed. With an unhindered oxygen rich surface, underlying highly polarizable lattice structure, and large accessible surface area, barium titanate nanoparticles are investigated as a potentially useful medium for photoreactive detoxification of chemical warfare agent vapors.

Recently, owing to the discovery of graphene, porous carbons experienced a revitalization in their explorations. However, nowadays, the focus is more on search for suitable energy advancing catalysts sensing, energy storage or thermal/light absorbing features than on separations. In many of these processes, adsorption, although not emphasized sufficiently, can be a significant step. It can just provide a surface accumulation of molecules used in other application-driving chemical or physical phenomena or can be even an additional mechanism adding to the efficiency of the overall performance. However, that aspect of confined molecules in pores and their involvement in the overall performance is often underrated. In many applications, nanopores might silently advance the target processes or might very directly affect or change the outcomes. Therefore, the objective of this communication is to bring awareness to the role of nanopores in carbon materials, and also in other solids, to scientists working on cutting-edge application of nonporous carbons, not necessary involving the adsorption process directly. It is not our intention to provide a clear explanation of the small pore effects, but we rather tend to indicate that such effects exist and that their full explanation is complex, as complex is the surface of nanoporous carbons.

A binary system composed of carbon dots (CDs) and N-doped CDs (N-CDs) embedded in an organic matrix was used for the analysis of cholesterol by MALDI (matrix-assisted laser desorption and ionization time-of-flight) mass spectrometry, as a model for detection of small, biologically relevant molecules. The results showed that both CDs are sensitive to the cholesterol and can be used either alone or in a binary system with 2,5-dihydroxybenzoic acid (DHB) to enhance the detection process. It was found that both COOH and NH2 groups on CDs surface contributed to the enhancement in the cholesterol detection by MALDI mass spectrometry in the presence of inorganic cations. Nevertheless, in the presence of NaCl, N-CDs led to a better reproducibility of results. It was due to the coexistence of positive and negative charge on N-CDs surface that led to a homogeneous analyte/substrate distribution, which is an important detection parameter. The enhancing effect of carbon dots was linked to a negative Gibbs energy of the complex formation between CDs, Na+, cholesterol and DHB, and it was supported by theoretical calculations. Moreover, upon the addition of CDs/N-CDs, such features as a low ionization potential, vertical excitation, dipole moment and oscillator strength positively affected the cholesterol detection by MALDI in the presence of Na+. © 2021 Elsevier Inc. This is accepted peer-reviewed version of the article: Houdová, D., Soto, J., Castro, R., Rodrigues, J., Pino-González, M. S., Petković, M., ... & Algarra, M. (2021). Chemically heterogeneous carbon dots enhanced cholesterol detection by MALDI TOF mass spectrometry. Journal of Colloid and Interface Science, 591, 373-383. DOI:[http://dx.doi.org/10.1016/j.jcis.2021.02.004]

In search for new alternative sources of energy carbon materials placed themselves as a valuable alternative to replace efficient noble metal- or transition metal-based catalysts. Even though the search for this kind of efficient catalysts started from the discovery and wonders of graphene, soon it has been established that to bring a catalytic activity for oxygen reduction to graphene an introduction of heteroatoms to its matrix or defect engineering is a must. The intent of this review is to present a brief journey on the development of heteroatom -doped “flat” carbons for an oxygen reduction electrocatalysis, followed by an indication of the role of defects as a general driving force, through heteroatom-doped porous carbons to heteroatom-free porous carbons. The emphasis is on importance of porosity, no necessary that 3-D engineered. The development of that concept is presented in the chronological order. Since to summarize all works on this topic sounds as a rather impossible task, and numerous reviews on the specific aspects of carbon-based metal-free ORR catalysts have been published recently, our intention is to stress the works where other factors than an alteration in the electronic/structure affect or could affect the ORR efficiency. These other factors include oxygen accessibility to small pores and its adsorption there. Even though the development of pores certainly is associated with an increase in the level of defect, the pore- influenced oxygen reduction mechanisms addressed here differs from that on the electronic defects-based catalytic sites.

International audience; This paper addresses the challenges of explaining the behavior of porous carbons in cutting-edge applications related to energy storage, catalysis, photocatalysis, and advanced separation based on reactive adsorption. It is a summary of the outcomes of the extensive discussion which took place during the workshop “Beyond Adsorption-II: new perspectives and challenges for nanoporous carbons,” organized as a satellite event to the International Carbon Conference on July 20th , 2019 in New York. It is not our intention to provide a tutorial on the applications, characterization or performance testing of porous carbons; we would rather like to focus on the controversy of the results and phenomena, on the explanation of findings, and on raising concerns to the growing carbon-researching scientific community about the importance of understanding the features of nanoporous carbons by choosing an appropriate characterization technique that will bring meaningful information. We want to emphasize that nanoporous carbons have unique features ensuring them making a marked advance in science and technology. Even though recent studies have shown their potential in various emerging applications, the origin of such performance is not yet well understood. Thus, scientists are encouraged to focus on a precise characterization of porous carbons using a set of complementary techniques for triggering future technological developments.

New composites have been synthesized containing nanographite (nGr) particles as platforms for the deposition of UiO-66 crystals. The samples were analyzed by X-ray diffraction, thermogravimetry, N2 adsorption and scanning electron microscopy. The addition of nGr markedly increased the porosity determined by N2 adsorption (0.5 nm ultramicropores were formed, and the volume in pores > 1.1 nm increased). This was the result of defects formation either on UiO-66 or at the nGr/UiO-66 interface. To assess the adsorptive properties and the accessibility of the pores, adsorption of H2, CO2, C2H4 and C2H6 was measured. The results have shown that not only the extent of the porosity but also the interactions with the graphite phase and the accessibility to the pores affect the amount adsorbed and the strength of adsorption. Generally, the formation of composites had a positive effect on the adsorption properties owing to an increased surface heterogeneity and porosity.

Smart textiles consisting of cotton, Cu-BTC MOF and oxidized graphitic carbon nitride, g-C

Nanoporous carbons are important materials applied in many fields of modern technology from separation, catalysis to energy-related applications such as those in energy storage, lithium batteries, or fuel cell electrodes. Even though they are relatively old materials, extensive efforts continue on their modifications, improvement, and design. The latter is mainly concentrated on the porosity control of its development and tailoring toward the desired applications. In this chapter, the main types of nanoporous carbons along with their synthesis and characterization methods are addressed. The main steps of each method are mentioned, variations leading to porosity alteration listed, and the basic surface features presented. Our intention is rather not to demonstrate the superiority of each method of carbon synthesis or of the resulting materials properties over others but to indicate a broad spectrum of opportunities to those who chose to synthesize/use nanoporous carbons for their target applications.

S-doped nanoporous carbon, and commercial activated carbons, as received or modified by an incorporation of sulfur and nitrogen functional groups to their surface, were tested as low concentration formaldehyde (1 ppmv) adsorbents. The breakthrough capacities, in dry and wet conditions, were measured. The surface properties of the samples were evaluated using nitrogen sorption, potentiometric titration, thermal analysis, and XPS. The incorporation sulfur and/or nitrogen functional groups led to an increase in the amount of HCHO removed from air. These group (pyridines, amines, thiophenes, sulfones) when located in large pores increase the utilization of the carbon surface for formaldehyde adsorption providing chemical reactivity. In this aspect, rich in sulfur carbon of a relatively low surface was found as the most efficient formaldehyde adsorbent. Its HCHO adsorption capacity was 7.15 × 10−4 mg m−2 whereas on melamine modified carbon of a high surface area 4.23 × 10−4 mg m−2 were adsorbed. On the microporous carbon of basic nature reactions of HCHO with phenols block this carbon porosity and thus excluded the adsorption centers in ultramicropores for physical adsorption decreasing the adsorption capacity. Water in the system decreases the HCHO capacity between 10 and 30%, owing to its competitive adsorption on polar centers.