The effect of moisture on the volatile organic compound (VOC) adsorption on biomass-derived metal–organic framework composites is significant in practical applications. In this study, wood-based metal organic frameworks (MOF199-W) and hydrophobic MOF199-W (HMOF199-W) were developed using HKUST-1 (MOF199) and long alkyl chains to investigate the adsorption performance of toluene and enhance the selectivity of adsorption under high humidity conditions. The results demonstrated that HKUST-1 could be anchored onto the surface of wood vessels and fibers through coordination with Cu 2+ , resulting in an improved surface area in comparison to natural wood. The toluene adsorption capacity of MOF199-W with a 20 % loading was comparable to that of an equivalent amount of MOF199, with adsorption capacities of 323.5 mg/g and 369.9 mg/g, respectively. Further, the Yoon-Nelson model was found to adequately describe the dynamic adsorption process. Following the introduction of long alkyl chains, MOF199 and MOF199-W were endowed with strong hydrophobic character (water contact angle of 107.0 ◦ , 104.0 ◦ , and water uptake of 30.5 mL/g, 55.3 mL/g). With the increase in humidity, the adsorption performance of MOF199 and MOF199-W for toluene sharply decreased, but HMOF199 and HMOF199-W still maintained the adsorption capacities at 304.7 mg/g and 226.7 mg/g, even under 80 % RH conditions. Therefore, HMOF199-W has shown great potential in wooden building materials with the ability for toluene capture under humid conditions.
Bohao Mei,Pengfei Jiao,Yao Xie,Yili Zhao,Yingzhan Li,Hongchen Liu
Conductive nanocellulose aerogels possess durability and sensitivity by using as piezoresistive sensors. Those aerogels are mostly prepared via a “bottom-up” strategy by using nanocellulose or dissolved and regenerated cellulose as raw materials. However, there is a pressing need to further enhance their sustainability and economic viability. To alleviate these issues, cellulose aerogel can alternatively be made via a “top-down” technique that entails the direct removal of contaminants from naturally porous biomass. Herein, conductive aerogels with exceptional mechanical flexibility and ultrahigh specific surface area were created. Delignified wood was partially dissolved and regenerated to created nanocellulose fibrils with spider web structure inside the pores of wood. After modification with silane coupling agent and carbon nanotubes (CNTs), flexible conductive wood aerogel (C-WA) were obtained. The specific surface area of C-WA was as high as 333.82 m 2 /g, which was 45 times of that of wood. C-WA could maintain its good resilience even after 1000 cycles, showing high compression resilience and excellent fatigue resistance (stress retention rate was 87.22%, height retention rate was 99.5%). The utilization of C-WA as a pressure sensor demonstrated remarkable attributes, including ultra-fast response and stability within the designated range. Furthermore, it exhibited exceptional sensing performance even after enduring 2000 stable cycles. The system is capable of real-time, accurate, and efficient detection of human motion signals, showcasing immense potential for future applications in wearable electronic products.
Activated carbon fibers (ACFs) are prepared from the discarded fir wood using two-step melt-spinning and CO 2 activation post-treatment. Then, composites composed of these ACFs and Ni, Co-layered double hydroxides (NiCo-LDH@ACF) are synthesized by a microwave-assistant hydrothermal strategy. NiCo-LDHs agglomerated around ACFs, forming core-shell structures with sheet- or microsphere-like morphologies, which provide large surface area, hierarchical porosity, and numerous active sites for efficient charge and mass transfer. The NiCo-LDH@ACFs are used as an active material to construct the supercapacitors, the highest of capacitance and the corresponding rate performance of which are equal to 1453.3 F/g at 1 A/g and 78% at 10 A/g by microwave-assistant hydrothermal at 120 °C, respectively. We also use this material to assemble an asymmetric supercapacitor using activated carbon derived from fir bark as a negative electrode. The resulting device demonstrates excellent capacitance (equal to 146.9 F/g at 1.6 V), very high energy density (equal to 52.2 Wh/kg at 800 W/kg), and cycle life (judging by the 79.8% capacitance retention after 10000 cycles).
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