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A novel polyimide copolymer (ZnTPP-PI) was synthesized through molecular engineering and a copolymerization method, which achieves high energy storage density, and excellent thermal stability and mechanical properties.

Rational design and facile preparation of low-cost and efficient catalysts for the selective converting of biomass-derived monosaccharides into high value-added chemicals is highly demanded, yet challenging. Herein, we first demonstrate a N doped defect-rich carbon (NC-800-5) as metal-free catalyst for the selective oxidation of d -xylose into d -xylonic acid in alkaline aqueous solution at 100 °C for 30 min, with 57.4% yield. The doped graphitic N is found to be the active site and hydroxyl ion participating in the oxidation of d -xylose. Hydroxyl ion and d -xylose first adsorb on NC-800-5 surface, and the aldehyde group of d -xylose is catalyzed to form germinal diols ion. Then, C–H bond break to yield carboxylic group. Furthermore, NC-800-5 catalyst shows high stability in recycled test.

Three-dimensional (3D) printing has attracted more attention in food industry because of its potential advantages, including the ability to create customized products according to individual's sensory or nutritional requirements. However, the production of high-quality 3D printed foods requires the availability of edible bio-inks with the required physicochemical and sensory attributes. Starch, as one of the important sources of dietary energy, is widely used in food processing and is considered as one kind of versatile polymers. It is not only because starch has low prices and abundant sources, but also because desirable modified starch can be obtained by altering its physicochemical properties through physical, chemical and enzymatic methods. This article focuses on the utilization of starch as materials to create food-grade bio-inks. Initially, several kinds of commonly used 3D printers are discussed. The factors affecting the printing quality of starch-based materials and improvement methods are then reviewed, as well as areas where future researches are required. The applications of 3D printed starch-based materials in food industry are also introduced. Overall, starch appears to be one kind of useful substances for creating edible bio-inks that can be utilized within 3D food printing applications to create a wide variety of food products.

Renewable and low-cost biomass is an ideal sustainable alternative to petroleum-based resources, but producing biomass-based carbon electrode with high performances remains a challenge. Herein, we propose a facile self-assembly strategy to fabricate a biomass-derived N, S co-doping carbon electrode from lignosulfonate without any activation or template process. Taking advantage of the coordination between Fe ions and lignosulfonate, the resultant carbon exhibits a spherical structure with abundant graphitized nanosheets, leading to a high specific surface area with rational pore structure, which are beneficial to the electron/ion transport and storage. The high contents of doping N (8.47 wt%) and S (2.56 wt%) significantly boost the electrochemical performances. As a supercapacitor electrode, the carbon material displays high specific capacitance of 390 F g−1, excellent cycling stability and high energy density of 14.7 W h kg−1 at a power density of 450 W kg−1. This study provides a potential strategy for synthesizing cost-effective heteroatom-doped carbon materials from biomass with abundant functional groups and heteroatom sources, such as chitosan, collagen, and gelatin. Graphical Abstract

Formation and investigation of zein/carboxymethyl cellulose composite nanoparticles to co-deliver quercetin and resveratrol.

A bamboo derived N-doped carbon displayed superior ORR/OER activity and successfully served as a bulk-phase air cathode for a rechargeable zinc–air battery.

Biomass-based protic ionic liquids (BILs), green solvents with inherent properties, have the potential as precursors of functionalized catalytic carbon materials. Simple one-step design and preparation of BILs-based porous carbon-based materials remains a challenge. Our demonstration here was to use BIL as an important precursor for synthesizing porous carbon-coated CoP nanocrystals by facile one-pot carbonization process. The as-prepared CoP@NPC-900 has a specific surface area of 979.67 m2 g−1 without activator and simultaneously exhibits excellent hydrogen evolution reaction (HER) performance with a low overpotential of 181 mV at 10 mA cm−2 and small Tafel slope of 59 mV dec−1 in acid solution. In addition, density functional theory (DFT) calculations indicate lower adsorption free energy and rapid electron transfer between CoP nanocrystals and N, P co-doped porous carbon (NPC) are key factors of improving the HER performance. Our research opens up a new use of BILs, as well as provides a facile strategy to promote practical application of transition metal phosphides for HER.

The preparation of inexpensive, high-performance non-noble metal catalysts for selective oxidation of biomass-derived monosaccharides to high value-added chemicals is challenging but in high demand. Herein, we successfully synthesized a nickel-embedded carbon nanotube (Ni-NCNT) catalyst to selectively convert the monosaccharides into sugar acids under mild condition. The Ni-NCNT catalyst was highly reactive towards glucose and xylose oxidation, reaching 90.8% yield of gluconic acid and 88.4% yield of xylonic acid under the optimal condition. Theoretical calculations revealed that the intrinsic reaction mechanism of xylose oxidation involves the activation of the oxidant, adsorption of xylose, dissociation of the formyl C–H bond in xylose, formation of chemisorbed xylonic acid, and desorption of xylonic acid. The dissociation of the formyl C–H bond and the formation of adsorbed xylonic acid are key steps in the oxidation of xylose. The OH−, instead of O2, acted as a direct oxidant and was crucial for the xylose oxidation. The highly active and cost-effective Ni-NCNT developed in this study provided a promising route to generate valuable chemicals from biomass.

Despite the fact that high-valent nickel-based oxides exhibit promising catalytic activity for the urea oxidation reaction (UOR), the fundamental questions concerning the origin of the high performance and the structure-activity correlations remain to be elucidated. Here, we unveil the underlying enhanced mechanism of UOR by employing a series of prepared cation-vacancy controllable LiNiO

High dielectric (high-k) polymer matrix composites (PMCs) have attracted much attention owing to their moderate dielectric property, good thermal stability, and excellent mechanical flexibility, as well as facile processability, light weight, and low cost. Herein, we report an in-situ synthesis strategy to fabricate high-performance high-k PMCs. A novel perovskite CsPbBr3/rGO/polyimide composite is fabricated by in-situ polymerization of poly(amic acid) (PAA) followed by thermal imidization, in-situ chemical reduction of graphene oxide (GO), and in-situ crystallization of CsPbBr3 nanoparticles. The fillers are uniformly dispersed in the polyimide (PI) matrix due to the multiple in-situ conversion processes, which form numerous micro-capacitors to enhance the dielectric permittivity. Attributing to the synergetic effect between rGO and CsPbBr3 nanocrystals, the CsPbBr3/rGO/PI composite showed a high dielectric permittivity up to 213, a high energy storage density of up to 5.20 J cm−3, and a dielectric loss less than 0.35. Besides, the thermal stability of the composites is enhanced (5% weight loss temperature (T5%) > 523 °C), and the mechanical strength is well retained under a relatively low filling amount of fillers (10 wt% CsPbBr3). Therefore, the as-fabricated CsPbBr3/rGO/PI composites would be promising for applications in energy storage polymer thin-film capacitors, and this research also opens a new avenue to fabricate high-k PMCs with good comprehensive properties.

Interfacial design is one of the most promising ways in improving mechanical properties of nanocomposites. In this work, a multifunctional aerogel with excellent mechanical performances, sensing sensitivity, and fire retardancy is fabricated by taking advantage of metal coordination between biopolymer and Fe3+. Montmorillonite (MMT) nanosheets are added to induce a ‘brick and mortar’ structure. The coordination remarkably reduces structural defects, leading to well-formed lamellas that can effectively distribute stress under sever compression without plastic deformation. The structural merits impart the aerogel highly reversible compressibility even at 99 % strain and superior durability. Besides, it demonstrates high sensing performance in wearable health monitoring devices, and shows fire resistance property that can maintain elasticity in a flame. The work offers a facile and effective method to create multifunctional aerogels from various polymers.

Mesoporous graphitic carbon nitride (mpg-C3N4) has been developed as a metal-free heterogeneous photocatalyst for thiocyanation transformations. The reaction proceeds efficiently by utilizing air as a green oxidant under mild reaction conditions, which affords SCN-containing compounds in moderate to excellent yields. Meanwhile, the practicality of this protocol is further demonstrated by the reusability of the mpg-C3N4 photocatalyst and the scaled-up reaction. Furthermore, detailed mechanistic studies clearly demonstrate the role of oxygen.

The selective oxidation of monosaccharides into sugar acids is an important reaction for the production of biomass-based chemicals, but the design of an efficient catalyst remains a big challenge. Herein we report a series of efficient and stable surface functionalized carbon nanotube supported palladium catalysts for the selective oxidation of monosaccharides into sugar acids at room temperature. The palladium nanoparticles supported on alkaline carbon nanotubes (Pd/CNT-N) showed the highest reaction activity. The maximum gluconic acid yield of 98.3% and xylonic acid yield of 95.8% were obtained at 30 °C within 180 min. DFT calculations revealed that the mechanism of xylose oxidation to xylonic acid involved the activation of OH−, adsorption of xylose, dissociation of the formyl C–H bond in xylose, formation of chemisorbed xylonic acid, and desorption of xylonic acid. The activation energy barrier for xylose oxidation over Pd/CNT-N is lower than that of Pd/CNT-O, explaining that the basic groups on CNT are more beneficial for accelerating monosaccharide oxidation and enhancing the sugar acid selectivity. This work not only presents a new facile route to produce sugar acid at room temperature, but also provides a basis to design and develop efficient catalysts with surface functionalized supports for various catalytic reactions.

The development of emulsion templated functional materials has achieved great progress in the past decades in academic and industrial fields. Recently, new building blocks such as graphene, transition metal carbides and nitrides (MXenes) and nanocellulose have been used in the fabrication of emulsion templated functional materials (EFMs). Intrinsic characteristics of these nano building blocks along with the various material formats and structures endow the functional materials with excellent properties and diverse applications. Herein, the latest progresses in emulsion templating mechanisms, emerging nano building blocks, and material formats including monolith, film and microcapsule for EFMs are reviewed first. Typical applications of these functional materials are critically discussed in the fields of sensing, energy storage and conversion, fire resistance and thermal insulation, water purification, and microdroplet transportation. Current challenges, future prospects and research opportunities of EFMs are also discussed finally.

Developing efficient active transition metal phosphide (TMP) bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) for alleviating the future energy crisis is crucial and challenging. Herein, we developed a facile self-assembly strategy for the one-step fabrication of core–shell Co2P nanoparticles encapsulated in nitrogen and phosphorus codoped porous carbon (Co2P@NPPC) via in situ carbonization and phosphorization. Due to the collaborative effect between NPPC and Co2P, the obtained Co2P@NPPC hybrid revealed robust electrocatalytic performance toward the HER and OER. Impressively, it exhibited a lower overpotential of 147 mV for HER and 316 mV for OER to reach the current density of 10 mA cm−2. Remarkably, it only required a low cell voltage of 1.65 V to reach the current density of 10 mA cm−2, with long-time reliable stability. Density functional theory (DFT) calculations suggest that the introduction of phosphorus into cobalt can weaken the H-adsorption free energy and increase the electronic states of Co2P.

Synthesis of D-xylonic acid, a high value chemical feedstock, from biomass chemicals through a photocatalytic process is of great significance in respect of economical and sustainable concerns, and therefore has aroused considerable attention. Herein, a TiO2/Ti3C2(TT) photocatalyst was designed for the oxidation of xylose to D-xylonic acid under ambient conditions. The photocatalyst is fabricated by in situ growth of TiO2 nano-particles on Ti3C2 nanosheets and exhibits 64.2% of D-xylonic acid yield with excellent stability. The mechanistic study indicates that the electron transfer from TiO2 to Ti3C2 significantly increases the life time of light-induced charge carriers, and hence improved photocatalytic performance.

Photoreforming of lignocellulose for sustainable H2 generation appears to be a good option at the time that biomass wastes are being degraded. Recently, polymeric carbon nitride (PCN) has emerged as a promising alternative for the photorefoming reaction, however, its photocatalytic performance is largely limited by its severe recombination of charge carriers. Here, we developed an approach, for the first time, to construct a curly-like carbon nitride nanosheets with the formation of in-plane surface dyadic heterostructure for steering the charge transfer and optimizing the electronic band structure. This PCN material shows superior photoreforming H2 evolved activity of 122.77 μmolh−1 (i.e. 4092 μmolh−1g−1) from the aqueous lignocellulose solution (using Pt as cocatalyst), 15.6 folds of pristine PCN under visible light irradiation, together with an apparent quantum efficiency (AQE) of 7.87% (λ = 420 nm). It enables the visible-light-driven conversion of several kinds of lignocellulose including the monosaccharides, disaccharides, hemicellulose, and cellulose. Additionally, when used as a photocatalyst for water splitting, it achieves a remarkable H2 production rate of 22043 μmolh−1g−1 (∼56.0 folds’ increases than pristine PCN) with a superior high AQE of 41.2%, as well as a high CO reduction rate of 56.3 μmolh−1 from the photocatalytic CO2 conversion, 24.5 times than pristine PCN.