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Natural polymer‐derived nanofibrils have gained significant interest in diverse fields. However, production of bio‐nanofibrils with the hierarchical structures such as fibrillar structures and crystalline features remains a great challenge. Herein, an all‐natural strategy for simple, green, and scalable top‐down exfoliation silk nanofibrils (SNFs) in novel renewable deep eutectic solvent (DES) composed by amino acids and D‐sorbitol is innovatively developed. The DES‐exfoliated SNFs with a controllable fibrillar structures and intact crystalline features, novelty preserving the hierarchical structure of natural silk fibers. Owing to the amphiphilic nature, the DES‐exfoliated SNFs show excellent capacity of assisting the exfoliation of several 2D‐layered materials, i.e., h‐BN, MoS2, and WS2. More importantly, the SNFs‐assisted dispersion of BNNSs with a concentration of 59.3% can be employed to construct SNFs/BNNSs nanocomposite membranes with excellent mechanical properties (tensile strength of 416.7 MPa, tensile modulus of 3.86 GPa and toughness of 1295.4 KJ·m−3) and thermal conductivity (in‐plane thermal conductivity coefficient of 3.84 W·m−1·K−1), enabling it to possess superior cooling efficiency compared with the commercial silicone pad. [ABSTRACT FROM AUTHOR]

We report the synthesis of CoSx nanosheets from a 1,2-ethanedithiol/n-butylamine quasi-ionic liquid with the assistance of compressed CO2 at ambient temperature. The CoSx achieves a current density of 10 mA cm−2 at an overpotential of 271 mV for the oxygen evolution reaction. Furthermore, our method is applicable to the fabrication of other transition metal chalcogenides. [ABSTRACT FROM AUTHOR]

As ionic liquid analogues or quasi-ionic liquids, deep eutectic solvents (DESs) have been applied in many fields in the past few years. Herein, a novel PEGylated DES composed of PEG 200 and thiourea was formed for the first time and used for solvothermal synthesis of nickel cobalt sulfides. The structure and composition of the as-synthesized sulfides can be tuned by adjustment of the ratio of the reactants. The PEGylated DES plays multiple roles as a solvent, a shape-control agent, and a sulfur source in the synthesis of sulfides. Compared with traditional sulfuration routes, this proposed route is cost-effective and energy-efficient by combining solvothermal synthesis and the sulfuration process. The prepared sulfides were used as catalysts for electrochemical water oxidation and they exhibited excellent oxygen evolution reaction (OER) performance, especially for NiCo2S4 with hierarchical pores. The overpotential (η) demand was 337 mV for the current density reaching 10 mA cm−2 and the Tafel slope was 64 mV dec−1 in an alkaline medium (1 M KOH) for NiCo2S4. In addition, NiCo2S4 demonstrated long-term stability with little deactivation after either thirty hours of continuous operation or two thousand cycles and a high faradaic efficiency of 95.8%. Synergistic effects including a relatively high Brunauer–Emmett–Teller area, abundant active sites, easy diffusion of electrolytes and oxygen gas, and strong structural integrity contribute to the high activity and long-term stability of the catalyst for OER. This study provides a new method for the synthesis of hierarchically structured metal sulfides for energy conversion and storage applications. [ABSTRACT FROM AUTHOR]

The efficient removal and storage of radioactive nuclear contaminants including an isotope of iodine (131I) has attracted great concern especially after the explosion of the Fukushima nuclear power plant. In this study, deep eutectic solvents (DESs) are proposed for the removal and storage of iodine (I2). These DESs can be obtained by simply mixing two simple components (also cheap and biodegradable), which form liquids with melting points far below that of the individual components. A series of hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs) are selected for the preparation of DESs. The properties and I2 capture efficiency of the prepared DESs have been investigated. The results indicate that some DESs have higher efficiencies for I2 removal than the previously reported materials. Among them, ChI–methylurea shows the best I2 uptake efficiency of approximately 100% within 5 hours. Moreover, ChI–methylurea exhibits a good capability of I2 storage with only 4.6% of the iodine evaporated after 10 hours of strong N2 sweeping, which is also important since I2 is easy to sublimate. Additional calculations also suggest that the high efficiency for I2 capture by DESs mainly comes from the formation of halogen bonding (XB) between DESs and I2. This work opens a new way for the application of DESs. [ABSTRACT FROM AUTHOR]

Electricity-driven oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a highly attractive strategy for biomass transformation. However, achieving industrial-grade current densities remains a great challenge. Herein, by modulating the water content in a solvothermal system, Ni 3 S 2 /NF with stabilized and shorter Ni-S bonds as well as a tunable coordination environment of Ni sites was fabricated. The prepared Ni 3 S 2 /NF was highly efficient for electrocatalytic oxidation of HMF to produce FDCA, and the FDCA yield and Faraday efficiency could reach 98.8% and 97.6% at the HMF complete conversion. More importantly, an industrial-grade current density of 1000 mA cm -2 could be achieved at a potential of only 1.45 V vs. RHE for HMFOR and the current density could exceed 500 mA cm -2 with other bio-based compounds as the reactants. The excellent performance of Ni 3 S 2 /NF originated from the shorter Ni-S bonds and its better electrochemical properties, which significantly promoted the dehydrogenation step of oxidizing HMF. Besides, the gram-scale FDCA production could be realized on Ni 3 S 2 /NF in a MEA reactor. This work provides a robust electrocatalyst with high potential for practical applications for the electrocatalytic oxidation of biomass-derived compounds., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

This work is a mechanistic study of the CO 2 reaction with diamines under both dry and wet conditions. All protic α,ω-diamines R1H1N1-(CH 2 ) n -N2H2R2, with n = 1-5 and R1 and R2 = H and/or CH 3 , were investigated. Depending on the nature of the diamine, the reaction was found to follow one of two concerted asynchronous reaction mechanisms with a zwitterion hidden intermediate. Both mechanisms involved two processes. The first process consisted of a nucleophilic attack of the nitrogen N1 of the first amine group on the carbon of CO 2 , accompanied by the transfer of a hydrogen atom H1 from N1 to the nitrogen N2 of the second amine group, leading to the formation of a carbamate zwitterion. The subsequent process corresponds to the transfer of a hydrogen atom H2 from the second amine group N2 to an oxygen atom of CO 2 , thus ending the reaction by the formation of carbamic acid. The structure of the zwitterion hidden intermediate was determined using the reactive internal reaction coordinates (RIRC), a reaction pathway visualization tool, consisting of a 3D representation of the potential energy versus the internuclear distances N2-H1 and N2-H2, which correspond to the bond being formed and the bond being broken, respectively. The life span of the transitory species, i.e., the zwitterion, was found to depend on the nature of the second amine group. For primary amines, the life span of the zwitterion was "short", whereas for secondary amines, it was "long". The corresponding mechanisms were termed the "early" and "late" asynchronous mechanism, respectively. Regardless of the mechanism, the activation barriers were found to decrease with the length of the carbon chain linking the two amine groups, with an asymptotic behavior from n = 4. Involvement of a water molecule generates a significant catalytic effect for diamines with short carbon chains ( n < 4), whereas for longer chain diamines, water has a slightly adverse effect.

{ 1 H- 29 Si}- 1 H double cross polarization inverse detection (DCPi) solid-state NMR, has recently been shown to be a powerful tool for studying molecules adsorbed on the silica surface. In this contribution, we develop an improved version (MCPi) which incorporates a block of multiple contact pulses, and quantitatively compare the sensitivities of MCPi and DCPi over a typical range of experimental parameters. The MCPi pulse sequence aims at higher sensitivity and robustness for studying samples with various relaxation characteristics. In the case of dimethyl sulfoxide (DMSO) molecules adsorbed on the silica surface, MCPi performs equally well or up to 2.5 times better than DCPi over a wide range of parameters. The applicability to and performance of MCPi on composite materials was demonstrated using a sample of polymer-silica composite, where significantly higher sensitivity could be achieved at very long total mixing times. The results also showed that both techniques are surface specific in the sense that only the groups close to the surface can be detected., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

We report the synthesis of CoS x nanosheets from a 1,2-ethanedithiol/n-butylamine quasi-ionic liquid with the assistance of compressed CO 2 at ambient temperature. The CoS x achieves a current density of 10 mA cm -2 at an overpotential of 271 mV for the oxygen evolution reaction. Furthermore, our method is applicable to the fabrication of other transition metal chalcogenides.

In this study, the fine regulation of the dissolution and regeneration of microcrystalline cellulose (MCC) using very low pressure (0-0.2 MPa) CO 2 in a mixed solvent of dimethyl sulfoxide (DMSO) and 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) at a very low temperature (30 °C) was achieved. The solubility of MCC in DMSO/DBU (weight ratio of DMSO W DMSO = 0.90) could reach 9.0% at 30 °C and under CO 2 pressure of 0.2 MPa. A similar phenomenon was observed in the mixed solvent DMSO/1,1,3,3-tetramethylguanidine (TMG). Moreover, ATR-FTIR, NMR, UV-Vis, TGA, XRD and DFT computational analyses were used to investigate the dissolution mechanism. It was concluded that in the mixed solvent (DMSO and organic base), DMSO helped to dissociate ion-pairs into free ions by balancing the concentration of free ions and the number of hydrogen bonds at W DMSO = 0.90. Interactions between CO 2 and the solvent mixture were explored, and the results indicate that the optimum CO 2 pressure not only promotes the formation of ionic bonds but also accelerates the formation of covalent bonds. In this way, these interactions prevent the MCC molecules from aggregating and facilitate the dissolving of MCC. This study gives a thorough insight into the dissolution mechanism and specificity of MCC in the CO 2 -DMSO/organic base solvent system, which could be helpful for the utilization and transformation of cellulose.