Preparation And Application Of Cellulose Acetate Porous Nanocomposites

The rapid development of global technology and economy has caused the rapid consumption of traditional petrochemical energy and brought serious burdens and pollution to the environment.The development of efficient clean energy storage materials and conversion devices is a research hot spot in the field of energy chemistry.As a new type of energy electrochemical storage device,supercapacitors and fuel cells are considered to be promising clean energy devices.Supercapacitors have the advantages of high power density,long cycle life,good stability,and safe operation,but the disadvantage is that their energy density is still relatively low compared with lithium-ion batteries and nickel-hydrogen batteries.Activated carbon is the earliest supercapacitor electrode material,but it is difficult to control the pore size and pore structure during the preparation of activated carbon,which affects the transfer of charge inside it,which limits its application in electric double layer capacitors.In this paper,the use of cellulose acetate to construct a three-dimensional microstructured electrode material by thermally induced phase separation can effectively shorten the diffusion distance of ions and provide large cycle capacity at smaller sizes and higher energy densities.Oxidation reduction?ORR?is an important electrocatalytic reaction in fuel cells.Carbon-supported platinum-based catalysts?Pt/C?are widely used as fuel cells due to their high activity.Due to the high cost of precious metal Pt,it is greatly limited.In practical applications,carbon has high electron and thermal conductivity,and carbon materials containing hetero elements can adjust its electronic structure and transport properties.Therefore,non-metallic carbon material carbon with high specific area of impurities is a suitable choice.The ORR catalytic activity is improved by constructing a three-dimensional continuous porous nitrogen doped non-precious metal carbon material.The main component of the cigarette butt is cellulose acetate,which is a material that is difficult to degrade in nature.It causes serious environmental pollution to water and soil.At present,there is no effective treatment method.It is a worldwide problem.The carbon source is applied to the supercapacitor electrode material by nitrogen doping,the non-precious metal catalyst of the fuel cell,and the superhydrophobic material is prepared for oil-water separation by chemically modifying the surface of the cigarette butt.Based on this,this paper focuses on the preparation of cellulose acetate nanocomposites and their applications in energy storage,adsorption,oil-water separation,does the following work:Preparation of three-dimensional porous monolithic acetate material and its adsorption on phenol:We have developed a single-step method to fabricate a cellulose acetate?CA?/A.pedunculata shell?APS?-derived activated carbon?AC?composite monolith by thermally induced phase separation?TIPS?for removal of toxic phenol from aqueous solution.The composite monolith was easily fabricated by TIPS of a CA solution in the presence of the dispersed AC,in which AC was well loaded onto the monolithic skeleton of CA.The as-obtained monolith showed maximum adsorption capacity of 45mg g^-1 at the initial phenol concentration of 0.8 mg mL^-1.The present composite is more convenient to recycle than powder adsorbents.Preparation of acetate/polyaniline composites for use in supercapacitors:A three-dimensional porous nitrogen-doped acetate/polyaniline electrode material was prepared by thermally induced phase separation.The electrode material has a uniform continuous three-dimensional structure with a porous specific area of 1889 m² g^-1 at a current density of 1 A g^-1.Its specific capacitance is as high as 257 F g^-1,with an energy density of 36 W h kg-1 and a power density of 50 W kg^-1.After 1000 cycles of stability test,its capacitance is not reduced,showing good Stability.The preparation of cigarette/polypyrrole composite carbon materials is applied to supercapacitors and fuel cells:The cigarette filter is made of carbon material,and the pyrrole is a nitrogen precursor.The N-doped non-metallic porous carbon-carbon material is prepared by high-temperature carbonization and KOH activation.The obtained carbon material has a three-dimensional porous structure and a large specific surface area(3420m² g^-1),at 1 A g^-1,the specific capacitance is 263 F g^-1,and at 5 A g^-1,after 5000 cycles,the original 90%specific capacitance can be maintained,which can be applied to the supercapacitor electrode material.In saturated oxygen 1M KOH electrolyte,the material has excellent electrocatalytic activity,initial potential of 0.88V?vs RHE?,high current density and 4 electron transfer mechanism,and compared with commercial 20%Pt/C?Eonset=0.93 V,E1/2=0.70 V?,it exhibits a positive half-slope potential of 0.74 V?vs RHE?and good stability,which can be applied to fuel cell catalytic redox reactions.Preparation of superhydrophobic cigarette butts for oil-water separation:Cigarette filter?CF?was modified by using different volume ratios of octadecyltrichlorosilane and methyltrimethoxysilane.When the volume ratio was 3:2,the modified CF had the high water contact angle of 155°.It could selectively and completely absorb silicone oil from an oil-water mixture and showed a good absorption capacity of 38.3 g g^-1.The absorbed oil was readily and rapidly recovered by simple mechanical squeezing,and it could be reused immediately without any additional treatments.The as-obtained superhydrophobic modified CF retained an absorption capacity of 80%for pump oil and 82%for silicone oil after 10 cycles.