Dayong Huang

A facile method was developed for preparing size-controlled silver nanoparticles supported by pyrolytic carbon from microcrystalline cellulose (MCC). The pyrolysis of cellulose-AgNO₃ mixture caused the oxidation of cellulose, resulting in carboxyl groups to which silver ions can bind firmly and act as nuclei for the deposition of silver nanoparticles. The structure and properties of the obtained nanocomposite were characterized by using a scanning electron microscope (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD). The results suggest that silver nanoparticles were integrated successfully and dispersed uniformly in the pyrolytic carbon matrix. The average particle size varied between 20 nm and 100 nm in correlation to the dose of silver nitrate and temperature of pyrolysis. The products showed high electric conductivity and strong antimicrobial activity against Escherichia coli (E. coli).

The study on preparation of lignin-containing cellulose nanofiber (LCNF) with high-yield, high-efficient, low-cost is a great challenge in large-scale production. Regulating hydrogen-bonding network by changing the content of lignin is of great significance to improve the efficiency of defibrillation of cellulose. In this paper, the LCNF with high yield (91.55%) was fabricated by oxidizing Brassica Campestris (BC) straw to partially remove the lignin, followed by ball-milling and high-density ultrasonic treatment. The atomic force microscope results reveal that LCNF exhibit fiber network structure with a typical diameter of 2-5 nm similar to those of elementary crystallites. Variations in the structure and hydrogen bonding characteristics of the products are further determined based on the FT-IR results followed deconvolution fitting, showing that intra and intermolecular hydrogen-bonding energies and distances decrease with the increase of degree of oxidization. Furthermore, the LCNF films with high tensile strength (225.78 MPa), good UV-blocking (80%) and water-resistant were constructed by vacuum assisted filtration. This research will provide an effective and convenient approach to obtain the LCNF materials with high-yield and widen its application fields.

Fe-Al (hydr)oxide nano-/micro-particles were well grown and dispersed on a wheat straw template, which was characterized by a scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and a vibrating sample magnetometer (VSM). The adsorption mechanism of the biomass-based Fe-Al (hydr)oxide nanocomposite was studied by the adsorption isotherms, which followed the Langmuir model better than the Freundlich and Temkin models. In particular, a synergistic adsorption by the mixed Fe-Al (hydr)oxide nano-/micro-particles based on the wheat straw was found, with higher maximum adsorption capacity (Q₀) than that of the material containing only Fe₃O₄ or Al(OH)₃ nano-/micro-particles, which was most obvious when the mole ratio of Fe to Al was 1:1. The degree of this unusual effect was reasonably determined by the departure between the experimental and calculated maximum adsorption capacity (Q₀-Q₀(cal)), which showed that the synergistic effect was most pronounced when the mole ratio of Fe to Al was approximately 1:1. The good adsorption capacity of the mixed Fe-Al (hydr)oxide nano-/micro-particles and the good dispersity by the wheat straw matrix were combined in the biomass-based Fe-Al (hydr)oxide nanocomposite. The nanocomposite material showed high adsorption capacity for both fluoride (F^-) and arsenic (As(Ⅲ) and As(Ⅴ)), and had the advantage of magnetic separation by tuning its compositions.

Cellulose with 15 % fatty oil is converted to a hydrocarbon‐rich oil comprised mainly of alkylbenzenes and aliphatic hydrocarbons through a synergic deoxy reforming (SDR) process. To further decrease the oxygen content and investigate the carbon distribution in the hydrocarbon oil, metal carbides (M₂C, M=Mo, W) supported on molecular sieves (ZSM‐5, MCM‐41, SBA‐15) with different pore structures were synthesized and employed as catalysts. The impacts of the M₂C particles on the pore size of the supports and the catalytic selectivity were investigated. The ZSM‐5 series of catalysts shows a relatively high selectivity for alkylbenzenes, especially Mo₂C/ZSM‐5, because of the abundant acid sites on the catalyst surfaces, whereas the MCM‐41 and SBA‐15 series of catalysts, especially W₂C/MCM‐41, show a relatively high selectivity for alkanes, which is attributed to their mesoporous structure. Additionally, Mo₂C/MCM‐41 catalysts show the highest deoxygenation efficiency of 95.7 %. This research provides a rational catalyst design to control the carbon distribution and components in SDR oil and paves the way for the full utilization of biomass waste and waste/gutter oil.