Composites combining electrostatic charge accumulation and faradic reaction mechanisms are especially attractive high-performance supercapacitor electrodes for electrochemical energy storage. Up to now, it is difficult to prepare low-cost carbon composites from renewable resources. In this work, an outstanding and low-cost composite was fabricated by using sustainable N-self-doped carbon framework as a hierarchical porous carbon substrate from renewable resource. The N-self-doped carbon framework was fabricated from chitosan via a facile yet unique self-assembly and ice template method without any physical or chemical activation, and exhibited hierarchical porous structure. This texture not only allowed the efficient infiltration and uniform coating of polyaniline (PANI) in the inner network but also permitted a rapid penetration and desorption of electrolytes. Due to short diffusion pathway, uniformly coating of PANI, and high accessibility of PANI to electrolytes, the composite electrode had a very high supercapacitance of 373 F g–1 (1.0 A g–1) and excellent rate capability (275 F g–1, 10 A g–1) in a three-electrode system. The symmetric supercapacitor also showed a supercapacitance of high up to 285 F g–1 (0.5 A g–1), and a very high energy density of 22.2 Wh kg–1. Furthermore, the composite also presented a good cycling stability.Keywords: Carbon composite; Chitosan; Polyaniline; Supercapacitor;

A simple and effective synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones and their derivatives from aldehydes, β-dicarbonyl compounds and urea or thiourea using D-xylonic acid both as a green solvent and an effective catalyst is described. Taking the environment and economy into account, the work presented here has the merits of environmental friendliness, easy operation, simple work-up, excellent yields and the avoidance of organic solvents and inexpensive catalysts. In addition, the good properties of D-xylonic acid have also been validated by the synthesis of 5-phenyl-1(4-methoxyphenyl)-3[(4-methoxyphenyl)-amino]-1H-pyrrol-2(5H)-one and 12-phenyl-9,9-dimethyl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one. The synthesized compounds were characterized by FT-IR, 1H NMR, 13C NMR and melting point.

Converting cellulose to renewable energies and chemicals is the most promising and sustainable route to solving the crisis of fossil fuel resources. Up to now, however, it is still a big challenge to effectively transform recalcitrant cellulose into targeted compounds. For the first time, this study proposes a new and highly effective catalysis system with a synergy effect to convert cellulose into formic acid and levulinic acid simultaneously by using in situ carbonic acid from CO2 as a green acid in the presence of CrCl3. The synergy effect of in situ carbonic acid and CrCl3 could highly effectively hydrolyze cellulose to glucose, isomerize glucose to fructose, dehydrate fructose to HMF, and rehydrate HMF to formic acid and levulinic acid in a one-pot way. Here, 49% formic acid and 32% levulinic acid could be obtained from cellulose at a moderate condition. Our results demonstrated that this new catalysis system is comparable to other catalysis systems, and in situ carbonic acid can be used as a low-cost acid to replace mineral acids such as H2SO4, HCl, and H3PO4 and organic acids such as C6H6O3S, H2C2O4, and Cl3CCOOH to constitute novel, highly effective, low-cost, and less environmental impact catalysis systems for producing formic acid and levulinic acid from cellulose.Keywords: Carbon dioxide; Cellulose; Formic acid; In situ carbonic acid; Levulinic acid; Lewis acid

•A novel and mild route to prepare electrospun cellulose acetate (CA) supported Ag@AgCl composites was proposed.•The electrospun CA membrane was employed as a support for Ag@AgCl crystals.•The catalysts showed facet-dependent photocatalytic properties on degradation of methyl orange.•The catalysts were synthesized at the room temperature and activated under visible light.•The CA membrane based catalysts could be retrieved easily without centrifugation process.Electrospun cellulose acetate (CA) membrane was employed as a support that provided sites for AgCl crystals in situ growth. The Ag@AgCl crystals on electrospun CA composites with exposed {1 0 0} and {1 1 1} facets were fabricated at room temperature by a double diffusion technique. The crystal structure, morphology, composition, and absorption light ability of CA supported Ag@AgCl were characterized utilizing X-ray powder diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflection-infrared intensity (ATR-IR), X-ray photoelectron spectroscopy measurements (XPS), energy dispersive spectrometer (EDS) and ultraviolet–visible (UV–vis) diffuse reflectance spectra, respectively. The photocatalytic activity of the catalysts was evaluated using methyl orange (MO) as a target. The CA supported cubic Ag@AgCl catalyst exhibited much higher catalytic activity than octahedral catalyst in terms of the degradation of MO under visible light. The 10 mg CA based cubes could completely degrade MO (10 mg L−1) in 160 min. The photocatalyst still exhibited a good catalytic ability after three times.

A water-soluble, ratiometric fluorescent pH probe, L-SRhB, was synthesized via grafting spirolactam Rhodamine B (SRhB) to lignosulfonate (LS). As the ring-opening product of L-SRhB, FL-SRhB was also prepared. The pH-response experiment indicated that L-SRhB showed a rapid response to pH changes from 4.60 to 6.20 with a pKa of 5.35, which indicated that L-SRhB has the potential for pH detection of acidic organelle. In addition, the two probes were internalized successfully by living cells through the endocytosis pathway and could distinguish normal cells from cancer cells by different cell staining rates. In addition, L-SRhB showed obvious cytotoxicity to cancer cells, whereas it was nontoxic to normal cells in the same condition. L-SRhB might have potential in cancer therapy. L-SRhB might be a promising ratiometric fluorescent pH sensor and bioimaging dye for the recognition of cancer cells. The results also provided a new perspective to the high-value utilization of lignin.Keywords: biomass; cancer sensing; FRET; ratiometric sensor; Rhodamine B;

Hierarchical porous N-doped carbons have attracted great interest in energy storage and CO2 capture applications due to their unique porous structure and physicochemical properties. Fabrication of cost-effective and eco-friendly hierarchical porous N-doped carbons from renewable biomass resources is a sustainable route for future energy storage. However, it is still a big challenge to produce N-doped carbons with hierarchical porous structure from cellulose, which is the most abundant and widely available renewable resource on earth. Here, we designed a facile and effective strategy to produce hierarchical porous N-doped carbons from cellulose for high-performance supercapacitor and CO2 capture applications. In this method, hierarchical porous cellulose aerogels were first obtained via a dissolving–gelling process and then carbonized in NH3 atmosphere to give hierarchical porous N-doped carbon aerogels with more interconnected macropores and micropores. Due to the unique porous structure and physicochemical properties, the as-prepared N-doped carbon aerogels had a high specific capacitance of 225 F g−1 (0.5 A g−1) and an outstanding cycling stability. For the first time, we also demonstrated that this N-doped carbon aerogel exhibited a exceptional CO2 adsorption capacity of 4.99 mmol g−1, which is much higher than those of other porous carbons. This novel hierarchical porous N-doped carbon has great potential applications in CO2 capture, energy storage, porous supports, and electrochemical catalysis.

Catalytic process is the key process for many chemical industries. In this study, a novel heterogeneous Pd (CMH–Pd(0)) has been prepared by the deposition of palladium nanoparticles (Pd NPs) onto the surface of carboxymethyl functionalized hemicelluloses using ethanol as solvent and in situ reducing agent. The as prepared catalyst was characterized by TEM, HR-TEM, XRD, FT-IR, TGA and XPS. The loading level of Pd in the CMH–Pd(0) catalyst was 0.38 mmol g−1. The catalyst showed high catalytic activity and versatility towards Heck coupling reactions under aerobic conditions and could be readily recovered and reused in at least five successive cycles without obvious loss in activity. The catalyst is promising for its renewability, environmental benefits, efficient catalytic activity, mild reaction conditions, simple product work-up and easy catalyst recovery.

Hierarchical porous N-doped carbons show great potential applications in energy storage and CO2 capture. Renewable biomass chitosan, which is abundant and simultaneously contains large amounts of N and C, is an ideal alternative to fossil resources for sustainable and scale-up production of cost-effective N-self-doped carbons. In this work, we employed a new and effective strategy to obtain 3D hierarchical porous N-self-doped carbons from chitosan. The hierarchical porous structure of the N-self-doped carbons could be easily tailored to obtain nanorod interconnected and fiber-wall interconnected architectures without using any porogen, catalyst or activator. The nanorod interconnected porous carbon displayed a high specific surface area of 1408 m2 g−1 while the fiber-wall interconnected porous carbon exhibited an excellent specific capacitance of 261 F g−1 (0.5 A g−1) due to the desirable hierarchical framework. In addition, these hierarchical porous carbons had a good CO2 capture performance (3.07–3.44 mmol g−1 at 25 °C). This unique method is supposed to be a new strategy to create novel 3D hierarchical porous carbons for promising applications in supercapacitors, lithium ion batteries, fuel cells and sorbents.

The application of biopolymer-based catalyst in catalysis is attracting more and more attention in the field of chemistry. Lignosulfonic acid (LSA), which is an organic waste generated as a byproduct from the pulp and papermaking industry, could serve as a retrievable sustainable heterogeneous catalyst for multicomponent reactions under solvent-free conditions, such as one-pot synthesis of benzoxanthenes by a condensation reaction of dimedone with aldehyde and 2-naphthol in excellent yields. Furthermore, the as-synthesized solid acid catalyst could be used for several cycles without significant loss of catalytic activity. These results clearly show that the lignin-derived catalyst is economic, eco-friendly, and promising for green chemical reactions from low-cost feedstocks and may find wide applications.Keywords: Amidoalkyl naphthols; Benzoxanthenes; Biomass; Lignosulfonic acid; Multicomponent reaction

In this study, an efficient, reusable, and environmental catalytic system consisting of sugarcane bagasse (an agricultural and sugar mill waste material, SCB) and KI was applied to the cycloaddition of carbon dioxide (CO2) to epoxides or aziridines under mild conditions for the first time. Their catalytic cycloaddition activities were found to be well correlated with the large quantities hydroxyl groups in SCB, which had a synergetic effect with the halide anion of KI. The as-prepared catalytic system also exhibited excellent cycloaddition activities for various epoxide or aziridine substrates as well. Moreover, the catalyst could be recovered and reused multiple times without obvious loss in activity. The present method represents an integrated and ideal green process for the utilization of biomass and “carbon neutral” resources, which has a high potential for large-scale fixation of CO2 into value-added chemicals.Keywords: Carbon dioxide fixation; Cycloaddition reaction; Sugarcane bagasse

Using a novel and facile method, we synthesized a family of ultrahigh molecular weight, lignosulfonate-based polymers (ALSs) via alkyl chain coupling polymerization. Gel permeation chromatography (GPC) showed a significant increase in weight-average molecular weights (Mws), from 42800 Da of ALS1 to 251000 Da of ALS5—one of the highest Mws among reported lignosulfonates (LSs) to date. Functional group content measurements, FTIR and 1H-NMR confirmed the efficient polymerization by nucleophilic substitution coupling mechanism and suggested a straightforward relationship between the polymerization of lignosulfonate (LS) and consumption of phenolic hydroxyl groups. Moreover, hollow nanospheres were obtained via self-assembly of water-soluble ALS and were investigated by DLS, SEM, TEM and AFM. The hollow sphere structure, with a hydrophilic core and a hydrophobic shell, was confirmed by XPS and elemental analysis. Stable, quasi-solid nanospheres were obtained from ALS by the addition of cetyl trimethyl ammonium bromide (CTAB). Furthermore, ALS2, with its relatively high molecular weight, showed unexpectedly better dispersion properties than the raw material LS and naphthalene sulfonate formaldehyde condensate (NSF) for coal–water slurry. The effective polymerization route to improving Mw and the self-assembly from polymer-only ALS provide novel avenues for high-value application of lignin, a sustainable and abundant bioresource.

Palladium nanoparticles (PdNPs) were successfully prepared using xylan-type hemicellulose (XH) as a support and used for the first time as an efficient and recyclable catalytic system in organic synthesis. The morphology, composition, and thermal stability of the catalyst were studied by means of TEM, XPS, XRD, FT-IR, and TGA. The as-prepared catalyst was further catalytically tested in various C–C cross-coupling reactions and exhibited excellent catalytic activity in the Suzuki, Heck, and Sonogashira coupling reactions. The catalyst could be easily recovered by simple filtration and reused at least six times without significant loss of its catalytic activity. This work demonstrates the possibility of using XH as an efficient support for catalysis.

Stimulus-responsive hydrogels, which can undergo significant physicochemical changes in response to various physical or chemical stimuli, have drawn wide attention in many fields. In this study, novel photoresponsive hydrogels prepared by free radical copolymerization of xylan-type hemicellulose methacrylate with 4-[(4-acryloyloxyphenyl)azo]benzoic acid (AOPAB) were investigated, which showed multiresponsive behaviors to pH, water/ethanol alternating solutions, and light. The swelling ratios of the prepared hydrogels in distilled water decreased from 9.8 to 2.2 g/g with AOPAB content increase from 2% to 16%. The hydrogel displayed rapid swelling and deswelling performance in water and ethanol alternating solutions. Additionally, under UV irradiation the trans-conformation of azobenzene in the hydrogel would generally convert into the cis-conformation and resulted in the hydrophilic/hydrophobic balance variation of the hydrogel. Therefore, the hydrogel loaded with vitamin B12 (VB12) showed a higher drug cumulative release rate under UV irradiation than that without UV irradiation.

Preparation of biopolymer-based catalysts for the conversion of carbohydrate polymers to new energies and chemicals is a hot topic nowadays. With the aim to develop an ecological method to convert xylose into furfural without the use of inorganic acids, a biopolymer-derived catalyst (lignosulfonic acid) was successfully used to catalyze xylose into furfural in ionic acid ([BMIM]Cl). The characteristics of lignosulfonic acid (LS) and effects of solvents, temperature, reaction time, and catalyst loading on the conversion of xylose were investigated in detail, and the reusability of the catalytic system was also studied. Results showed that 21.0% conversion could be achieved at 100 °C for 1.5 h. The method not only avoids pollution from conventional mineral acid catalysts and organic liquids but also maked full use of a byproduct (lignin) from the pulp and paper industry, thus demonstrating an environmentally benign process for the conversion of carbohydrates into furfural.

Xylan-type hemicelluloses supported terpyridine–palladium(II) as a novel biomass-supported catalyst was synthesized and characterized in terms of morphology, composition, and thermal stability. The nano-Pd catalyst was further explored for Suzuki–Miyaura reaction between arylboronic acid and aryl halide under aerobic condition, with a yield up to 98 %. In particular, the catalyst exhibited both high catalytic activity and stability for Suzuki–Miyaura reaction. Furthermore, the catalyst could be easily recovered by simple filtration and reused at least six times without significant loss of its catalytic activity. This work provides a novel and effective supported catalyst, and broadens the applications of polysaccharides in green catalysis.

•Porous cellulose carbon aerogels were obtained via carbonized and activated simultaneously.•Cellulose carbon aerogel had a high specific surface area of 1364 m2/g and a high specific capacitance of 328 F g−1.•For the first time, we showed that the cellulose carbon aerogel had a good CO2 adsorption capacity.Fabrication of cost-effective and eco-friendly hierarchical porous carbons from the most abundant and widely available biomass cellulose represents a critical and sustainable way to solve the crisis of fossil resources. In this work, a hierarchical porous carbon aerogel with desirable macropores, mesopores, and micropores was obtained via dissolving-gelling and subsequent carbonizing-activating process. The CO2 activated carbon aerogel had a high specific surface area of 1364 m2/g and a high specific capacitance of 328 F g−1 (0.5 A g−1, 1.0 M H2SO4) as well as an outstanding cycling stability with 96% of the capacitance retention after 5000 charge/discharge cycles. More importantly, for the first time, we demonstrated that the cellulose-derived hierarchical porous carbon aerogel showed a good CO2 adsorption capacity of 3.42 mmol/g (at 1 atm and 298 K), which indicates the possibility of using this carbon aerogel for CO2 capture.Download full-size image

Palladium nanoparticles (PdNPs) were successfully prepared using xylan-type hemicellulose (XH) as a support and used for the first time as an efficient and recyclable catalytic system in organic synthesis. The morphology, composition, and thermal stability of the catalyst were studied by means of TEM, XPS, XRD, FT-IR, and TGA. The as-prepared catalyst was further catalytically tested in various C–C cross-coupling reactions and exhibited excellent catalytic activity in the Suzuki, Heck, and Sonogashira coupling reactions. The catalyst could be easily recovered by simple filtration and reused at least six times without significant loss of its catalytic activity. This work demonstrates the possibility of using XH as an efficient support for catalysis.