This study presents a sustainable approach for the valorization of spent coffee grounds(CG)by converting them into carboxylated cellulose nanofibrils(CG-TCNF)via formic acid/hydrogen peroxide pretreatment followed by ...This study presents a sustainable approach for the valorization of spent coffee grounds(CG)by converting them into carboxylated cellulose nanofibrils(CG-TCNF)via formic acid/hydrogen peroxide pretreatment followed by TEMPO/NaClO/NaClO_(2)-mediated oxidation.The pretreatment efficiently removed lignin,hemicellulose,and other non-cellulosic components,yielding purified cellulose(CG-C)with high crystallinity(CrI=84%).Subsequent regioselective oxidation introduced carboxyl groups at the C6 position of cellulose chains,achieving a high carboxylate content of 1.4 mmol/g.The resulting CG-TCNF exhibited a well-dispersed nanofibrillar morphology with an average width of 3.57 nm and a high specific surface area of 265 m^(2)/g.Comprehensive characterization confirmed the successful oxidation and nanofibrillation:Fourier TransformInfaraed(FT-IR)Spectroscopy revealed the characteristic carboxylate absorption bands,X-ray Diffraction(XRD)showed preserved cellulose I structurewith a slight reduction in crystallinity(CrI=79.2%),and zeta potential measurements indicated good colloidal stability(-45.23 mV)in aqueous suspension.Thermal analysis demonstrated that the introduced carboxyl groups reduced the thermal stability of the nanofibrils compared to the precursor cellulose.This work establishes a novel route for directly transforming coffee grounds into functional nanocellulose,highlighting its potential as a sustainable feedstock for high-value nanomaterials.展开更多
Aqueous zinc-iodine batteries(AZIBs)have attracted significant attention as the most promising next-generation energy storage technology due to their low cost,inherent safety,and high energy density.However,their prac...Aqueous zinc-iodine batteries(AZIBs)have attracted significant attention as the most promising next-generation energy storage technology due to their low cost,inherent safety,and high energy density.However,their practical application is hindered by the poor electronic conductivity of iodine cathodes and the severe shuttling effect of intermediate polyiodides.Here,we report a novel micropores carbon framework(MCF)synthesized from waste coffee grounds via a facile carbonization-activation process.The resultant MCF features an ultrahigh specific surface area and a high density of micropores,which not only physically confine iodine species to minimize iodine loss but also enhance the electronic conductivity of the composite cathode.Furthermore,biomass-derived heteroatom dopings(nitrogen functionalities)facilitate effective chemical anchoring of polyiodide intermediates,thereby mitigating the shuttle effect.UV–visible spectroscopy and electrochemical kinetic analyses further confirm the rapid transformation and inhibition mechanism of iodine species by MCF.Consequently,the MCF/I_(2)cathode delivers superior specific capacities of 238.3 mA h g^(−1)at 0.2 A g^(−1)and maintains outstanding cycling performance with a capacity retention of 85.2%after 1200 cycles at 1.0 A g^(−1).This work not only provides an important reference for the design of high-performance iodine-host porous carbon materials but also explores new paths for the sustainable,high-value utilization of waste biomass resources.展开更多
基金funded by the training Program for College Students’Innovation and Entrepreneurship of Jiamusi University in Jiamusi City,Heilongjiang Province(grant number S202410222123).
文摘This study presents a sustainable approach for the valorization of spent coffee grounds(CG)by converting them into carboxylated cellulose nanofibrils(CG-TCNF)via formic acid/hydrogen peroxide pretreatment followed by TEMPO/NaClO/NaClO_(2)-mediated oxidation.The pretreatment efficiently removed lignin,hemicellulose,and other non-cellulosic components,yielding purified cellulose(CG-C)with high crystallinity(CrI=84%).Subsequent regioselective oxidation introduced carboxyl groups at the C6 position of cellulose chains,achieving a high carboxylate content of 1.4 mmol/g.The resulting CG-TCNF exhibited a well-dispersed nanofibrillar morphology with an average width of 3.57 nm and a high specific surface area of 265 m^(2)/g.Comprehensive characterization confirmed the successful oxidation and nanofibrillation:Fourier TransformInfaraed(FT-IR)Spectroscopy revealed the characteristic carboxylate absorption bands,X-ray Diffraction(XRD)showed preserved cellulose I structurewith a slight reduction in crystallinity(CrI=79.2%),and zeta potential measurements indicated good colloidal stability(-45.23 mV)in aqueous suspension.Thermal analysis demonstrated that the introduced carboxyl groups reduced the thermal stability of the nanofibrils compared to the precursor cellulose.This work establishes a novel route for directly transforming coffee grounds into functional nanocellulose,highlighting its potential as a sustainable feedstock for high-value nanomaterials.
基金financial support from the National Natural Science Foundation of China(U23B20166,U21A20289)International Joint Doctoral Education Fund of Beihang University+5 种基金Open Fund of Key Laboratory of Biodiversity and Environment on the Qinghai-Tibet Plateau,Ministry of Education(KLBE2024001)the Australian Research Council(ARC)through the Future Fellowship(FT210100298)Discovery Project(DP220100603)Linkage Project(LP210200504,LP220100088,LP230200897)Industrial Transformation Research Hub(IH240100009)schemesthe Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077).
文摘Aqueous zinc-iodine batteries(AZIBs)have attracted significant attention as the most promising next-generation energy storage technology due to their low cost,inherent safety,and high energy density.However,their practical application is hindered by the poor electronic conductivity of iodine cathodes and the severe shuttling effect of intermediate polyiodides.Here,we report a novel micropores carbon framework(MCF)synthesized from waste coffee grounds via a facile carbonization-activation process.The resultant MCF features an ultrahigh specific surface area and a high density of micropores,which not only physically confine iodine species to minimize iodine loss but also enhance the electronic conductivity of the composite cathode.Furthermore,biomass-derived heteroatom dopings(nitrogen functionalities)facilitate effective chemical anchoring of polyiodide intermediates,thereby mitigating the shuttle effect.UV–visible spectroscopy and electrochemical kinetic analyses further confirm the rapid transformation and inhibition mechanism of iodine species by MCF.Consequently,the MCF/I_(2)cathode delivers superior specific capacities of 238.3 mA h g^(−1)at 0.2 A g^(−1)and maintains outstanding cycling performance with a capacity retention of 85.2%after 1200 cycles at 1.0 A g^(−1).This work not only provides an important reference for the design of high-performance iodine-host porous carbon materials but also explores new paths for the sustainable,high-value utilization of waste biomass resources.
