Fabrication and Enhanced Supercapacitive Performance of Fe_(2)N@Cotton-based Porous Carbon fibers as Electrode Material

With the emergence of supercapacitors(SCs),the creation of bio-based electrode materials has grown in significance for the advancement of energy storage.However,it is particularly difficult for cathode materials to meet the demands of practical uses due to their low energy density.Herein,MIL-88 was fabricated in situ on the surface of cotton fibers used in cosmetics,followed by creating Fe_(2)N@porous carbon fiber composite(Fe_(2)N@PCF)through heat treatment at various temperatures.Fe_(2)N@PCF-800 demonstrates excellent specific capacitance performance(552 F g^(-1) at 1 A g^(-1)).Meanwhile,The AC//Fe_(2)N@PCF-800 device exhibits the largest energy density of 38 Wh kg^(-1) at 800 W kg^(-1) and a long cycling stability(83.3%capacity retention after 6000 cycles).Our elaborately designed Fe_(2)N@PCF demonstrate multiple advantages:i)the Fe_(2)N@PCF-800 shows abundant mesopores,providing abundant ion-diffusion pathways for mass transport and rich graphite microstructures,improving electrical conductivity for electron transferowning;ii)the rich nitrogen dopants and Fe_(2)N structure within all carbon components increase the capacitance through their pseudocapacitive contribution.These findings highlight the importance of biomass derived carbon materials for SCs applications.

MnO/N—C anode materials for lithium-ion batteries prepared by cotton-templated combustion synthesis

We herein report a facile one-pot synthesis of MnO/N-doped carbon(N—C) composites via a sustainable cotton-template glycineenitrate combustion synthesis to yield superior anode materials for Li ion batteries. MnO nanoparticles with several nanometers were well-embedded in a porous N-doped carbon matrix. It displays the unique characteristics, including the shortened Li^+-ion transport path, increased contact areas with the electrolyte solution, inhibited volume changes and agglomeration of nanoparticles, as well as good conductivity and structural stability during the cycling process, thereby benefiting the superior cycling performance and rate capability. This favorable electrochemical performance of obtained MnO/N—C composites via a one-pot biomass-templated glycine/nitrate combustion synthesis renders the suitability as anode materials for Li-ion batteries.

Waste cotton fabric derived porous carbon containing Fe_(3)O_(4)/NiS nanoparticles for electrocatalytic oxygen evolution

Developing low-cost,active and durable electrocatalysts for oxygen evolution reaction(OER)is an urgent task for the applications such as water splitting and rechargeable metal-air battery.Herein,this work reports the fabrication of a metal and hetero atom co-doped fibrous carbon structure derived from cotton textile wastes and its use as an efficient OER catalyst.The free-standing fibrous carbon structure,fabricated with a simple two-step carbonization process,has a high specific surface area of 1796 m^2/g and a uniform distribution of Fe_(3)O_(4)/NiS nanoparticles(Fe_(3)O_(4)/NiS@CC).The composite exhibits excellent OER performance with an onset potential of 1.44 V and a low overpotential of 310 mV at the current density of 10 mA/cm^2in a 1.0 M KOH solution,which even surpass commercial Ru O_(2)catalyst.Additionally,this ternary catalyst shows remarkable long-term stability without current density loss after continuous operation for 26 h.It can be believed that the outstanding OER performance is attributed to the synergistic effect between the iron oxides and nickel sulphides,as well as the micro-meso porous carbon structure.This study demonstrates a new strategy to use conventional textile materials to prepare highly efficient electrocatalysts;it also provides a simple approach to turn textile waste into valuable products.