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Herein, we focus on the development of new nanocomposite porous membranes based on castor oil-derived polyurethane (PUBCO) and octadecylamine-functionalized cellulose nanocrystals (CNC-ODA) as compatible nanoreinforcements.

Attaining a synergistic merge between the performance of homogenous catalysts and the recyclability of heterogeneous catalysts remains until now a concerning issue. The main challenge is to design efficient, low-cost catalyst with outstanding reusability, facile recovery, and ease of retrieval and monitoring between the reuses. Despite the vast efforts in the development of silver nanoparticle–based catalyst for the reaction of hydrogenation of 4-nitrophenol, the aforementioned criteria are infrequently found in a chosen system. Herein, we report a MoS2 nanosheet/silver nanoparticle–anchored PES-based textile as an efficient and recyclable “dip catalyst” for the 4-NP hydrogenation in the presence of sodium bohydride as model reaction. The textile fabric–based catalyst was processed via a simple sono-coating approach using MoS2 nanosheets as first coating layer followed by an in situ deposition of silver nanoparticles. The “dip catalyst” fabric is rapidly and easily removed from the reaction and then reinserted in the batch system to attain over 10 reaction cycles. Additionally, the produced textile materials were characterized via spectroscopic and microscopic tools such as FTIR, XRD, SEM, and EDX. Moreover, the sources of the high catalytic activity are also discussed and a plausible reaction mechanism is suggested. The present study demonstrates the potential of metal nanoparticle-textile material combination for future applications in chemical sustainable catalysis for environmental remediation purposes.

A novel, environmentally friendly and simple method for chemical functionalization of microcrystalline cellulose (MCC) to produce organophilic cellulose nanocrystals (CNC-ODA) is herein proposed. Surface modification of MCC was successfully achieved by simple chemical oxidation followed by citric acid esterification and amidation reactions. The resultant nanocrystals were fully characterized for their chemical structure, morphology, crystalline structure, thermal stability, and surface hydrophobicity. FTIR analysis revealed that the long chain hydrocarbon structure was successfully grafted onto CNC surfaces. The crystallinity index of the cellulosic materials calculated by the Segal equation from the corresponding X-ray diffraction (XRD) patterns was relatively reduced from 83.27% for microcrystalline cellulose to 71.12% for organophilic cellulose nanocrystals (CNC-ODA). Moreover, CNC-ODA showed improved thermal stability than unmodified MCC as elucidated by TGA. Scanning electron microscopy, atomic force microscopy and transmission electron microscopy showed significant change in the size and shape of the produced nanocrystals. The effectiveness of ODA grafting was evidenced by the enhanced hydrophobicity and the long-term stability of the colloidal suspension of organophilic cellulose nanocrystals in various organic solvents which enables this material to be used as highly hydrophobic coating and reinforcing agent for solvent-borne nanocomposites systems. The adopted approach is qualified as environmentally friendly for mass-production of organophilic cellulose nanocrystals without any use of organic solvents or toxic reagents.

Engineering of versatile binding chemistry on graphene oxide surface using nucleophilic substitution/amidation reactions for highly efficient adsorption of Cd (II), Cu (II) and Pb (II) is herein proposed. Graphene oxide (GO) was used as a precursor for covalent bonding of hexamethylenediamine (HMDA) molecules via the nucleophilic substitution/amidation reactions on epoxy (C O C) and carboxyl ( COOH) groups to yield hexamethylenediamine functionalized graphene oxide (GO-HMDA) with multiple binding chemistries such as oxygen and nitrogen. Afterwards, GO-HMDA was encapsulated in alginate hydrogel beads with different loadings 5, 10, 15 and 20 wt% to produce Alg/GO-HMDA hybrid adsorbents for the removal of trace heavy metal ions from aqueous solution. Batch adsorption studies showed remarkable adsorption rates reaching 100% for Pb (II), 98.18% for Cu (II) and 95.19 for Cd (II) (~1 mg L−1) with only 15 wt% of GO-HMDA incorporated into the alginate beads. Moreover, Alg/GO-HMDA showed high removal efficiencies of heavy metals from tap water with a removal order of (Pb > Cu > Cd) similar to that observed in single aqueous solution. In Addition, the Alg/GO-HMDA adsorbents displayed excellent regeneration ability for six consecutive adsorption–desorption cycles confirming the high performance and potential of these adsorbents, for real heavy metals remediation in environment and in drinking waters in both single and multiple systems. Finally, the adsorption mechanism of traces heavy metals resulted from several phenomena including the electrostatic interactions occurring between the COOH groups of Alginate and the GO-HMDA surface groups as well as, through chelation interactions occurring between the metal cations and amino-functionalized groups of Alg/GO-HMDA 15 hybrid adsorbent.

Atomically 2D thin-layered structures, such as graphene nanosheets, graphitic carbon nitride nanosheets (g-C3N4), hexagonal boron nitride, and transition metal dichalcogenides are emerging as fascinating materials for a good array of domains owing to their rare physicochemical characteristics. In particular, graphitic carbon nitride has turned into a hot subject in the scientific community due to numerous qualities such as simple preparation, electrochemical properties, high adsorption capacity, good photochemical properties, thermal stability, and acid-alkali chemical resistance, etc. Basically, g-C3N4 is considered as a polymeric material consisting of N and C atoms forming a tri-s-triazine network connected by planar amino groups. In comparison with most C-based materials, g-C3N4 possesses electron-rich characteristics, basic moieties, and hydrogen-bonding groups owing to the presence of hydrogen and nitrogen atoms; therefore, it is taken into account as an interesting nominee to further complement carbon in applications of functional materials. Nevertheless, g-C3N4 has some intrinsic limitations and drawbacks mainly related to a relatively poor specific surface area, rapid charge recombination, a limited light absorption range, and a poor dispersibility in both aqueous and organic mediums. To overcome these shortcomings, numerous chemical modification approaches have been conducted with the aim of expanding the range of application of g-C3N4 and enhancing its properties. In the current review, the comprehensive survey is conducted on g-C3N4 chemical functionalization strategies including covalent and noncovalent approaches. Covalent approaches consist of establishing covalent linkage between the g-C3N4 structure and the chemical modifier such as oxidation/carboxylation, amidation, polymer grafting, etc., whereas the noncovalent approaches mainly consist of physical bonding and intermolecular interaction such as van der Waals interactions, electrostatic interactions, π-π interactions, and so on. Furthermore, the preparation, characterization, and diverse applications of functionalized g-C3N4 in various domains are described and recapped. We believe that this work will inspire scientists and readers to conduct research with the aim of exploring other functionalization strategies for this material in numerous applications.

Attaining a synergistic merge between the performance of homogenous catalysts and the recyclability of heterogeneous catalysts remains until now a concerning issue. The main challenge is to design efficient, low-cost catalyst with outstanding reusability, facile recovery, and ease of retrieval and monitoring between the reuses. Despite the vast efforts in the development of silver nanoparticle-based catalyst for the reaction of hydrogenation of 4-nitrophenol, the aforementioned criteria are infrequently found in a chosen system. Herein, we report a MoS

International audience; New green synthesis methods of novel commercially applicable carbocatalysts suitable for the catalytic oxidation of organic pollutants, remain a challenge. Herein, Nitrogen doped (N-PC), Sulfur doped (S-PC) and Co-doped (N, S-PC) porous carbon, were synthesized via a new facile environmentally functionalization approach followed by pyrolysis. Thus, Almond Shell (AS) as Bio-sourced material was used for porous carbon (PC) preparation as support. Thereafter, the introduction of Melamine, Diphenyl Disulfide and Thiourea on the PC matrix with high -COCl− and -CCl− groups facilitated the surface functionalization, and allowed us the introduction of high N and S heteroatoms contents in the PC networks surface. It was found that the optimized carbocatalysts could effectively activate PS, and exhibited excellent catalytic performances for the organic pollutants degradation, with an exceptionally low activation energy and fast kinetic reaction. Based on a systematic comparison, it was found that the N-PC exhibited the superior catalytic activity for activating the PS and degrading various organic pollutants. Such superior catalytic activity of the N-PC Carbocatalyst resulted from its high surface area, its low defect degree with the higher content of Graphitic-N. In addition, all experimental and theoretical investigations demonstrated the critical role of graphitic–N for the PS activation. It is expected that the doping process by N will significantly break the chemical inertness of the PC network and will make the N-PC surface more positively charged accelerating hence its interaction with the negatively charged S2O82−. Furthermore, the 1O2 was found to be the predominant reactive oxygen species (ROS) as assessed by radical scavenging tests and EPR experiments. The carbocatalysts were not easily influenced by the water aqueous phase, which give us more obvious advantages over the PS activation.

The present study focuses on the design of new nanocomposite films using bio-based thermoplastic polyurethane (TPU) as a polymer matrix and long chain amine functionalized reduced graphene oxide (G-ODA) as a nanofiller. G-ODA was successfully prepared via chemical grafting of octadecylamine and fully characterized by various physicochemical techniques. Dispersion experiments showed that the synthesized organophilic graphene could be easily dispersed in several organic solvents and forms a stable and homogeneous colloidal suspension. G-ODA was incorporated at different loadings (0.1, 0.3, 0.5 and 0.7 wt%) into the polyurethane (PU) matrix to prepare uniformly dispersed G-ODA based PU nanocomposites. The designated nanocomposites resulted in achieving enhanced thermal stabilities as well as excellent mechanical properties compared to the neat PU. Mechanical performance studies show a tremendous enhancement of the tensile strength (2.08 to 5.48 MPa) along with an increment of the tensile modulus (37.19 to 122.83 MPa), the elongation at break (9.67 to 28.91%) and the toughness (13.75 to 124.44 MJ m−3). In addition, the designed nanocomposites demonstrate limited moisture and water uptake, reduced permeability and enhanced surface hydrophobicity.

Herein, we report the design of a cost-effective catalyst with excellent recyclability, simple recuperation and facile recovery, and the examination between the reaction cycles via the development of self-supporting g-C3N4 nanosheets/Ag NPs polyester fabric (PES) using a simple, facile and efficient approach. PES fabrics were coated via a sono-coating method with carbon nitride nanosheets (GCNN) along with an in situ setting of Ag nanoparticles on PES coated GCNN surface producing PES-GCNN/Ag0. The elaborated textile-based materials were fully characterized using FTIR, 13C NMR, XRD, TGA, SEM, EDX, etc. Catalytic performance of the designed “Dip-Catalyst” demonstrated that the as-prepared PES-GCCN/Ag0 has effectively catalyzed the hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4. The 3 × 3 cm2 PES-GCNN/Ag0 showed the best catalytic activity, displaying an apparent rate constant (Kapp) equal to 0.43 min−1 and more than 10 reusability cycles, suggesting that the prepared catalyst-based PES fabric can be a strong nominee for sustainable chemical catalysis. Moreover, the coated fabrics exhibited appreciable antibacterial capacity against Staphylococcus epidermidis (S. epidermidis) and Escherichia coli (E. coli). The present study opens up new opportunities for the future design of a low cost and large-scale process of functional fabrics.

International audience; Herein, ethylenediamine functionalized porous carbon (PC-ED/1.5) was synthesized, then characterized by various methods and finally used as a functional material for Cu(II) and Pb(II) ion removal from water. XPS revealed the presence of numerous functionalities within the surface of PC including-NH and C-N-C groups. Furthermore, S BET , RS, XRD and FTIR analyses confirmed the changes implemented on the PC surface. Thereafter, a systematic study was implemented to analyze the interactions of the PC-ED/1.5 surface with Cu(II) and Pb(II) heavy metal ions. Hence, adsorption experiments showed that the PC-ED/1.5 exhibits maximum adsorption capacities of 123.45 mg g À1 and 140.84 mg g À1 for Cu(II) and Pb(II), respectively. Moreover, in situ electrostatic interactions occurring between the divalent cation and the PC-ED/1.5 functional groups was investigated. The mechanism involves chelation processes, electrostatic interactions and mechanical trapping of the metal ions in the adsorbent pores. Interestingly, a synergistic effect of the pores and surface active sites was observed. Finally, by using alginate bio-polymer we prepared membrane films of PC-ED/1.5 which showed long-term stability, regeneration capabilities and high mass recovery.

In the present investigation, layered graphitic carbon nitride (g-C3N4) was hybridized with Ag3PO4 via in situ precipitation route to design heterojunction structure. The crystal structure, textural, morphology, thermal stability and optical proprieties of the as-prepared materials was systematically characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption-desorption, scanning electron microscopy (SEM), Transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and UV–vis diffuse reflectance spectroscopy (DRS). The g-C3N4/Ag3PO4 composite was immobilized on FTO substrate to develop a photoanode catalyst, which was used in a typical photoelectrocatalytic process for Rhodamine B degradation. The results indicate that the g-C3N4/Ag3PO4 composite exhibit a higher photoelectrocatalytic activity for rhodamine B degradation due to the charge transfer/separation properties and prolonged lifetime of charge carriers as it was confirmed by photocurrent and electrochemical impedance spectroscopy results.