Research On Energy Storage Of Microdevices And Electrocatalytic Based On Silk And PAN Carbonization

In light of the escalating energy scarcity and environmental pollution challenges,the quest for advanced energy storage techniques and environmental remediation solutions has become increasingly urgent.Consequently,there has been a growing emphasis on textile-based energy storage and electrocatalytic technologies as promising avenues within the industry.Among these,interdigital planar micro supercapacitors（MSCs）and electrocatalytic NO₃^-reduction to NH₃（NO₃^-RA）catalysts have emerged as viable and effective approaches.However,the current planar interdigital structure of MSCs suffers from limitations such as low electronic conductivity,sluggish ion transfer rates,and high raw material costs.Similarly,the activity and selectivity of NO₃^-RA catalysts are still suboptimal.In view of these challenges,this article aims to integrate and innovate textile dyeing and electrochemical technologies,leveraging silk as the raw material,to expand the application of electrochemical energy storage.The focus is on constructing composite carbon nanofibers capable of electrocatalyzing environmental pollutants like nitrates and utilizing them for the synthesis of valuable chemical raw material ammonia.Specifically,the research delves into the realm of planar interdigital structure MSCs for energy storage and NO₃^-RA catalysts for ammonia synthesis.The details are as follows:（1）Investigation of Silk/EGaIn-based MSCs for energy storage.The preparation of highly conductive collector-based planar MSCs using the adsorption and chelation properties of natural biological macromolecules（silk fibroin SF,silk sericin SS,and sodium alginate SA）and gallium indium alloy（EGaIn）was conducted.Additionally,EGaIn conductive dispersion,conductive circuits,and interdigital mask-based EGaIn-graphene MSCs（EGaIn-G-MSCs）were developed by incorporating graphene conductive ink.The findings demonstrate the exceptional stability of EGaIn conductive dispersion,as the conductive circuit can illuminate an LED with constant brightness even under bending conditions.Moreover,the EGaIn-G MSCs exhibit remarkable electrochemical performance,with an equivalent series resistance of only 16Ω,a charge transfer resistance of 7Ω,and a time constant of 78 ms.The area-specific capacitance reaches an impressive 6 m F cm^-2,and even after 10,000 cycles,the capacitance retention rate remains at 80%,underscoring the excellent performance of these devices.（2）Preparation and Energy Storage of Carbonized Silk Fabric-Based MSCs.Carbonized silk power textiles undergo acid treatment to yield acid-treated carbonized silk fabric（ACSF）.By utilizing laser direct writing technology,ACSF is combined with graphite paper（GP）to fabricate ACSF-based MSCs（ACSF-GP-MSCs）.The presence of abundant oxygen-containing functional groups,such as carboxyl and hydroxyl groups,on the surface of the ACSF electrode significantly enhances the specific capacitance and promotes electrolyte permeability.Additionally,the"grass wrapped mud"structure creates a 3D multi-directional ion transport channel,further improving ion transport speed.Remarkably,ACSF-GP-MSCs demonstrate high area energy density(8.8-5.1μWh cm^-2)and power density(50-250μW cm^-2).These devices exhibit exceptional durability,with a capacitance retention rate of 98.5%even after 25,000 cycles.Importantly,the integrated series and parallel units of the prepared ACSF-GP-MSCs offer continuous power supply for wearable electronic watches.Overall,ACSF-GP-MSCs exhibit outstanding electrochemical performance and hold great promise for energy storage applications.（3）Preparation and Electrocatalytic Performance of Loaded Amorphous Copper PAN-Based Carbonized Nanofibers.Initially,a polyacrylonitrile（PAN）based composite nanofiber containing Zn Co₂O₄ nanoparticles was prepared through electrospinning.Subsequently,high-temperature carbonization was performed to obtain nitrogen-doped superporous carbon nanofibers（PCNF）carriers.On these carriers,highly dispersed amorphous copper nanoparticles（a Cu/PCNF）were synthesized using a solution reduction method,serving as catalysts for NO₃^-reduction to NH₃（NO₃^-RA）.The findings demonstrate that the nitrogen-doped PCNF carrier,with its abundant mesopores and strong interaction with copper species,facilitates the high dispersion of copper nanoparticles.Furthermore,the mild reduction liquid environment induces the amorphization of the copper nanoparticles.The synergistic effects of enhanced copper dispersion and amorphization increase the number of catalytic sites,improve the adsorption affinity of NO₃^-with the planar adsorption configuration,and promote the potential limiting steps of*NO protonation to*NHO.Calculations reveal that the ammonia yield and Faraday efficiency reach impressive values of 1.42 mol h^-1 g^-1 and 95.7%,respectively,surpassing the performance of the crystalline counterpart（c Cu/PCNF）.Moreover,a Cu/PCNF exhibits excellent electrochemical stability at-0.3 V,outperforming c Cu/PCNF and demonstrating its potential for limited electrochemical stability.