The Study On The Application Of Cathode Catalyst Derived From Triazine Framework In Microbial Fuel Cell

The energy shortage and water pollution are two major problems facing human beings.Microbial fuel cell（MFC）is a promising novel clean energy recovery technology,which utilizes microorganisms to decompose organic matter in wastewater while recovering electric energy.The cathode catalyst is an important factor affecting the performance of MFC.Therefore,developing low cost and efficient cathode catalysts is a key link in the popularization and application of MFC technology.Based on those,the cathode catalyst materials of MFC were studied in this work.（1）The amorphous covalent triazine framework（ACTF）as precursor was synthesized by ionothermal synthesis.The TTF,a nitrogen-doped carbon catalyst,was obtained by themolysis of ACTF at 900℃.The results showed that TTF got a high specific surface area(992.81 m²·g^-1)with abundant microporous and mesoporous,as well as high graphitization degree（I_D/I_G=0.98）,which was beneficial to the transport of matter and charge.The maximum power density（MPD）of MFC modified by TTF was 1895±61 m W·m^-2,110%higher than that of activated carbon（AC）.The CoNC,cobalt-modified nitrogen-doped carbon catalysts,were synthesized by pyrolysis of ACTF and Co Cl₂ at 900℃,and the doping ratio was optimized.The research indicated that the synergistic effect of Co nanoparticles,Co-N_x,pyridine-N and graphite-N in catalysts could enhance the catalytic activity of the catalysts for oxygen reduction reaction（ORR）.The MPD of MFC modified by CoNC-2 was 2210±56 m W·m^-2,17%higher than that of TTF.（2）The FeNC,iron-modified nitrogen-doped carbon catalysts,were synthesized by pyrolysis of ACTF and Fe Cl₃,and the effect of temperature was investigated after optimizing the doping ratio.Compared with other pyrolysis temperatures,FeNC2-900synthesized at 900℃got the highest content of Fe-N_X,which led to the best electrocatalytic performance.The synergistic effect of Fe₃C nanoparticles,Co-N_x,pyridine-N and graphite-N boosted the catalytic activity of FeNC2-900.The MPD of MFC modified by FeNC2-900 was 2617±44 m W·m^-2,38%higher than that of TTF.（3）The CoFeNC,Co-Fe co-modified nitrogen-doped carbon catalysts,were synthesized by pyrolysis of ACTF,Co Cl₂and Fe Cl₃,and the doping ratio was optimized.The results showed that CoFeNC-2 catalyst got the best catalytic performance,which was attributed to the electronic interaction between metal nanoparticles and nitrogen-doped carbon.The MPD of MFC modified by CoFeNC-2was 2497±68 m W·m^-2,32%higher than that of TTF.（4）The catalytic activity of catalysts was found to follow FeNC2-900>CoFeNC-2>CoNC-2.Due to the better catalytic activity of Fe-N_x than that of Co-N_x,the MFC modified by FeNC2-900 obtained the highest MPD of 2617±44 m W·m^-2among the three catalysts.Considering the synthesis cost of FeNC2-900,it was expected to promote the application of MFC.