Hydrogels have attracted much attraction for promising flexible electronics due to the versatile tunability of the properties. However, there is still a big obstacle to balance between the multi-properties and performance of wearable electronics. Herein, we propose a salt-percolated nanocellulose composite hydrogel which was fabricated via radical polymerization with acrylic acid as polymer networks (NaCl-CNCs-PAA). CNCs were utilized as a reinforcing agent to enhance the mechanical properties of the hydrogel. Moreover, the abundant hydroxyl groups endow the hydrogel with noncovalent interactions, such as hydrogen bonding, and the robustness of the hydrogel was thus improved. NaCl incorporation induced the electrostatic interaction between CNCs and PAA polymer blocks, thus facilitating the improvement of the stretchability of the hydrogel. The as-obtained hydrogel exhibited excellent stretchability, ionic conductivity, mechanical robustness and anti-freezing properties, making it suitable for self-powered sensing applications. A single-mode triboelectric nanogenerator (C-TENG) was fabricated by utilizing the composite hydrogel as electrodes. This C-TENG could effectively convert biomechanical energy to electricity (89.2 V, 1.8 µA, 32.1 nC, and the max power density of 60.8 mW m⁻² at 1.5 Hz.) Moreover, the composite hydrogel was applied for strain sensing to detect human motions. The nanocellulose composite hydrogel can achieve the application as a power supply in integrated sensing systems and as a strain sensor for human motion detection.

Grasses are potential candidate to replace wood as a raw material for pulping and paper making, and several processes have been developed to produce grass pulp. In this study, wheat straw was used as raw material, and the possibility of sequential treatment with a mechanical method and deep eutectic solvent (DES) to prepare high-quality dissolving pulp was explored. Firstly, the wheat straw was mechanically treated, and then the wheat straw was delignified using a choline chloride–lactic acid deep eutectic solvent. The results showed that the optimal treatment conditions of deep eutectic solvent were 110 °C, 6 h, and a solid–liquid ratio (ratio of pulp to DES) of 1:40. The removal rate of lignin was 82.92%, the glucose content of pulp was increased by 11.42%. The DES recovery rate was further calculated, and the results showed that the DES recovery rate was more than 50% with rotary evaporation. The pulp viscosity after bleaching was 472 mL/g, and the α-cellulose accounted for 81.79%. This treatment has advantages in biomass refining, and the total utilization rate of wheat straw reaches 72%. This study confirmed that combined mechanical and deep eutectic solvent treatment can effectively remove lignin from wheat straw to produce high-quality wheat straw dissolving pulp.

The ever-growing global demand for sustainable energy has promoted the development of zinc–air batteries with high energy density. However, the slow multi-electron kinetic process of the oxygen reduction reaction and oxygen evolution reaction still restricts the practical commercialization of this battery technology. Biomass-based carbon aerogels can be constructed into tunable three-dimensional hierarchical structural frameworks, which provide high specific surface area and tunable structural characteristics, offering opportunities to improve mass transport and catalytic-site accessibility. This paper systematically reviews the latest research progress in the preparation and structural regulation of biomass-based carbon aerogels and elaborates on the determining effect of directional sol–gel processes, advanced drying techniques, and activation mechanisms on pore structure. To further improve the bifunctional electrocatalytic activity, this paper highlights the key doping and modification strategies, including nitrogen doping, multi-element co-doping, as well as the precise immobilization of non-noble metal nanoparticles and single-atom active sites. In addition to serving as high-efficiency, self-supporting, and flexible air cathodes for energy storage devices, the excellent mechanical rebound performance and continuous conductive network of this type of carbon aerogel also make it suitable for high-sensitivity pressure sensors. In conclusion, rational design and modification of biomass precursors can open up a green and sustainable development path for next-generation multifunctional flexible electronic devices.