Waste to wealth: Oxygen-nitrogen-sulfur codoped lignin-derived carbon microspheres from hazardous black liquors for high-performance DSSCs

Carbon materials are effective substitutes for Pt counter electrodes(CEs) in dye-sensitized solar cells(DSSCs). However, many of these materials, such as carbon nanotubes and graphene, are expensive and require complex preparation process. Herein, waste lignin, recycled from hazardous black liquors,is used to create oxygen-nitrogen-sulfur codoped carbon microspheres for use in DSSC CEs through the facile process of low-temperature preoxidation and high-temperature self-activation. The large number of ester bonds formed by preoxidation increase the degree of cross-linking of the lignin chains, leading to the formation of highly disordered carbon with ample defect sites during pyrolysis. The presence of organic O/N/S components in the waste lignin results in high O/N/S doping of the pyrolysed carbon,which increases the electrolyte ion adsorption and accelerates the electron transfer at the CE/electrolyte interface, as confirmed by density functional theory(DFT) calculations. The presence of inorganic impurities enables the construction of a hierarchical micropore-rich carbon structure through the etching effect during self-activation, which can provide abundant catalytically active sites for the reversible adsorption/desorption of electrolyte ions. Under these synergistic effects, the DSSCs that use this novel carbon CE achieve a quite high power-conversion efficiency of 9.22%. To the best of our knowledge, the value is a new record reported so far for biomass-carbon-based DSSCs.

Hierarchically porous cellulose nanofibril aerogel decorated with polypyrrole and nickel-cobalt layered double hydroxide for high-performance nonenzymatic glucose sensors

With increasing emphasis on green chemistry,biomass-based materials have attracted increased attention regarding the development of highly efficient functional materials.Herein,a new pore-rich cellulose nanofibril aerogel is utilized as a substrate to integrate highly conductive polypyrrole and active nanoflower-like nickel-cobalt layered double hydroxide through in situ chemical polymerization and electrodeposition.This ternary composite can act as an effective self-supported electrode for the electrocatalytic oxidation of glucose.With the synergistic effect of three heterogeneous components,the electrode achieves outstanding glucose sensing performance,including a high sensitivity(851.4μA·mmol^(−1)·L·cm^(−2)),a short response time(2.2 s),a wide linear range(two stages:0.001−8.145 and 8.145−35.500 mmol·L^(−1)),strong immunity to interference,outstanding intraelectrode and interelectrode reproducibility,a favorable toxicity resistance(Cl^(‒)),and a good long-term stability(maintaining 86.0%of the original value after 30 d).These data are superior to those of some traditional glucose sensors using nonbiomass substrates.When determining the blood glucose level of a human serum,this electrode realizes a high recovery rate of 97.07%–98.89%,validating the potential for highperformance blood glucose sensing.

Cellulose aerogels decorated with multi-walled carbon nanotubes:preparation,characterization,and application for electromagnetic interference shielding

Electromagnetic wave pollution has attracted extensive attention because of its ability to affect the operation of electronic machinery and endanger human health.In this work,the environmentally-friendly hybrid aerogels consisting of cellulose and multi-walled carbon nanotubes(MWCNTs)were fabricated.The aerogels have a low bulk density of 58.17 mg·cm^(–3).The incorporation of MWCNTs leads to an improvement in the thermal stability.In addition,the aerogels show a high electromagnetic interference(EMI)SEtotal value of 19.4 dB.Meanwhile,the absorption-dominant shielding mechanism helps a lot to reduce secondary radiation,which is beneficial to develop novel eco-friendly EMI shielding materials.

Fabrication of cellulose aerogel from wheat straw with strong absorptive capacity

An effectively mild solvent solution containing NaOH/PEG was employed to dissolve the cellulose extracted from the wheat straw.With further combined regeneration process and freeze-drying,the cellulose aerogel was successfully obtained.Scanning electron microscope,X-ray diffraction technique,Fourier transform infrared spectroscopy,and Brunauer-Emmett-Teller were used to characterize this cellulose aerogel of low density(about 40 mg·cm^(–3))and three-dimensional network with large specific surface area(about 101 m2·g^(–1)).Additionally,with a hydrophobic modification by trimethylchlorosilane,the cellulose aerogel showed a strong absorptive capacity for oil and dye solutions.

Sustainable wood-based nanotechnologies for photocatalytic degradation of organic contaminants in aquatic environment

Wood-based nanotechnologies have received much attention in the area of photocatalytic degradation of organic contaminants in aquatic environment in recent years,because of the high abundance and renewability of wood as well as the high reaction activity and unique structural features of these materials.Herein,we present a comprehensive review of the current research activities centering on the development of wood-based nanocatalysts for photodegradation of organic pollutants.This review begins with a brief introduction of the development of photocatalysts and hierarchical structure of wood.The review then focuses on strategies of designing novel photocatalysts based on wood or its recombinants(such as 1D fiber,2D films and 3D porous gels)using advanced nanotechnology including sol-gel method,hydrothermal method,magnetron sputtering method,dipping method and so on.Next,we highlight typical approaches that improve the photocatalytic property,including metal element doping,morphology control and semiconductor coupling.Also,the structure-activity relationship of photocatalysts is emphasized.Finally,a brief summary and prospect of wood-derived photocatalysts is provided.

Synthesis of Mn Fe_2O_4/cellulose aerogel nanocomposite with strong magnetic responsiveness

Cellulose aerogel, with abundant three-dimensional architecture, has been considered as a class of ideal eco-friendly matrix materials to encapsulate various nanoparticles for synthesis of miscellaneous functional materials. In the present paper, hexagonal single-crystalline MnFe_2O_4 was fabricated and inserted into the cellulose aerogel using an in situ chemical precipitation method. The as-prepared MnFe_2O_4 nanoparticles were well dispersed and immobilized in the micro/nanoscale pore structure of the aerogel, and exhibited superparamagnetic behavior. In addition, the nanocomposite was easily actuated under the effect of an external magnetic field, revealing its strong magnetic responsiveness.Combined with the advantages of environmental benefits,facile synthesis method, strong magnetic responsiveness,and unique structural feature, this class of MnFe_2O_4/cellulose aerogel nanocomposite has possible uses for applications such as magnetically actuated adsorbents.