Study On Super-electrical And Electro-degradable Phenol Properties Of Pitch-based Porous Carbon

Coal tar pitch is a by-product of deep processing of coal.It is rich in reserves,low in price,and high in carbon content.It is often burned as solid waste,causing environmental pollution.How to realize the conversion of coal tar pitch to high-value chemical substances or materials is of great significance.Therefore,various carbon materials are prepared using coal pitch as a raw material.Not only can the production cost be effectively reduced,coal tar pitch high value-added utilization can be achieved,but also the pollution to the environment can be reduced.In this paper,coal-tar tar pitch was used as the carbon source.Pitch-based porous carbon was prepared by MgO template method and KOH activation method.The performance of supercapacitor and electrocatalytic degradation of phenol was studied.Coal pitch is a carbon source,melamine resin?MF?is a nitrogen source,magnesium acetate is a precursor of MgO,and KOH is an activator.Nitrogen-doped pitch-based porous carbons?NPCs?are prepared using MgO template method and KOH activation method.The physicochemical properties of NPCs such as morphology,pore structure,surface properties and composition were characterized by SEM,TEM,XRD,Raman,N₂ physisorption,elemental analysis and XPS.The results show that NPCs has high specific surface area(788²133 m² g^-1),abundant hierarchical porous structure and oxygen/nitrogen heteroatoms?9.59¹3.16 wt%?.The best NPC700 sample has a specific capacitance of 349 F g-1 at a current density of 1 A g-1 in a three-electrode system.When the current density is increased to 50 A g^-1,it still has excellent rate performance?79.9%?.In the two-electrode system,the specific capacitance of NPC700was 269 F g^-1 at a current density of 1 A g^-1.When the power density is 865 W kg^-1,the energy density is 21 W h kg^-11 in 1 mol L^-1 Na₂SO₄ electrolyte.Coal Coal-tar pitch was used as the main carbon source,and different resins?melamine MF,polyvinyl alcohol PVA,resorcinol RF?were used as the auxiliary carbon sources.Magnesium acetate and magnesium chloride were precursors of MgO template,combined with orthogonal design methods.Pitch-based hierarchical porous carbon?HPCs?was prepared by in-situ MgO template coupled with KOH activation method.The physicochemical properties of HPCs such as morphology,pore structure,surface properties and composition were systematically characterized.HPCs had high specific surface area(805¹170 m² g^-1)and high carbon yield?20%⁵0%?.In the three-electrode system,the HPC-PVA-a,HPC-RF-a and HPC-MgCl₂-a electrodes have high specific capacitance and excellent rate performance,that is,the specific capacitances were 350,321 and 329 F g^-1 at the current density of 1 A g^-1,respectively.When the current density was 50 A g^-1,the capacitor retention rates were 83.7%,84.1%and 84.3%.The HPC-PVA-a,HPC-RF-a and HPC-MgCl₂-a electrode shows specific capacitance as high as 251,234 and 245 F g^-1 at a current density of 1 A g^-1 in two electrode system.The HPC-PVA-a symmetric electrode has a high energy density of 22.3 Wh kg^-1 at 876W kg^-11 in 1 mol L^-1 Na₂SO₄ electrolyte.The above NPC700,HPC-PVA-a and HPC-RF-a active materials were used as the cathode,stainless steel mesh was used as the anode,and 0.1 mol L^-1 Na₂SO₄ solution was used as the electrolyte.The degradation of phenol was studied in in the electrocatalytic degradation of phenol reaction device.The effects of current density(24,32,48 mA?cm^-2),electrolysis time?0¹20 min?,distance between electrodes of cathode and anode?2,3 cm?on the degradation of simulation phenol wastewater were investigated,and the degradation mechanism of phenol was analyzed.The results show that when the current density is 48 mA?cm^-2,the distance between cathode and anode is3 cm,and the initial concentration of simulated phenol wastewater is 100 mg?L^-1,the electrolysis reaction time is 120 min,and The removal rates of simulated phenol wastewater by NPC700,HPC-PVA-a and HPC-RF-a cathodes can reach 90.6%,96.3%and 95.7%.