Search

Due to the natural cellulose encapsulated in both lignin and hemicellulose matrices, as well as in plant cell walls with a compact and complex hierarchy, extracting cellulose nanofibers (CNFs) from lignocellulosic biomass is challenging. In this study, a sustainable high yield strategy with respect to other CNF preparations was developed. The cellulose was liberated from plant cell walls and fibrillated to a 7–22 nm thickness in one bath treatment with H3PO4 and H2O2 under mild conditions. The cellulose underwent swelling, the lignin underwent oxidative degradation, and the hemicellulose and a small amount of cellulose underwent acid hydrolysis. The CNFs' width was about 12 nm, with high yields (93% and 50% based on cellulose and biomass, respectively), and a 64% crystallinity and good thermal stability were obtained from bagasse. The current work suggests a strategy with simplicity, mild conditions, and cost-effectiveness, which means that this method can contribute to sustainable development for the preparation of CNFs. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D BiOCl lamellar membrane with CNFs is constructed for photocatalyst. • Hydrogen evolution rate of BiOCl/CNF 2DLM is 4.7-times that of the BiOCl nanosheets. • Experimental and theoretical analyses revealed the effect of CNFs on photocatalysis. • CNFs can regulate hydrogen bonds networks of confined water. • Confined water promotes the release of H+ from H 2 O. Photocatalytic hydrogen evolution (PHE) is a sustainable alternative for generating green and clean energy. However, it requires the use of nanoscale photocatalysts, whose applicability is limited by their poor reusability and proton release from water molecules. Herein, a porous two-dimensional lamellar membrane (2DLM) photocatalyst was fabricated from bismuth oxychloride (BiOCl) nanosheets (BNs) and cellulose nanofibers (CNFs) via layer-by-layer self-assembly. The hybridization of the CNFs with the BNs improved the PHE rate of the resulting BiOCl/CNFs membrane (BCM). The optimal PHE rate was observed for a CNF content of 3.2 wt% and was 4.7-times that of raw BNs dispersed in an aqueous solution alone and 1.85-times that of the BiOCl membrane (BM). Moreover, the PHE rate remained unchanged even after 10 discontinuous cycles for a total time of 60 h. Comprehensive experimental characterization and molecular dynamics simulations confirmed that the introduction of the CNFs effectively regulated the hydrogen bond network of the confined water molecules, thus improving the efficiency of the conversion of H 2 O into H 2. Meanwhile, the optimization of the nanochannel sizes of the BNs by the hybridized CNFs accelerated water transport within the nanochannels. The 2DLM also showed excellent mechanical strength, flexibility, and translucence. This strategy of fabricating 2DLMs using a nanosheet photocatalyst and CNFs not only results in improved PHE performance but also should also aid the development of stable and reusable photocatalysts for other industrial applications. [ABSTRACT FROM AUTHOR]

Separating the fibers, deconstructing both the interlamellar structures and the intermicrofibrils structures in the cell wall, and cleaving the amorphous regions of cellulose (all reached in one bath chemical-assisted treatment), then extracting cellulose nanofibers (CNFs) from biomass, is both challenging and imperative. A simple, cost-effective and green strategy for extracting CNFs from bamboo using nitric acid and hydrogen peroxide (NCHP), to enable fibrillation via a cooperative mechanism, is demonstrated herein. NCHP-CNFs 13.1 ± 2.0 nm wide, with a high aspect ratio, 74% crystallinity, excellent UV resistance and high thermal stability, were successfully extracted by treatment in HNO3 aqueous solution, at a concentration of 3.2 mol/L, and treatment with 60.00 mmol/g H2O2 at 50 °C for 48 h. The yields of NCHP-CNFs reached 73% and 99% based on biomass and cellulose, respectively, due to the high delignification selectivity of OH+ and the mild aqueous conditions during the NCHP treatment. These NCHP-CNFs with excellent UV resistance can potentially be applied in the field of UV-resistant coatings, to replace organic and inorganic materials. [ABSTRACT FROM AUTHOR]