摘要
通过电化学氧化聚合法对石墨毡(GF)进行了聚吡咯(PPy)改性,并利用SEM、FTIR、XPS、LSV和EIS对聚吡咯改性石墨毡电极的形貌结构、元素组成和电化学性质进行了研究,采用H2O2生成速率表征了改性电极的两电子氧还原活性。考察了支持电解质种类和聚合时间对改性电极结构和氧还原性能的影响。结果表明,通过改性能够在石墨毡表面引入吡咯氮结构,在恒–0.45 V阴极电势的条件下,以硫酸钠为支持电解质制得改性电极的两电子氧还原活性最高,H2O2生成速率为24.82 mg/(L·cm2·h)。改性石墨毡的两电子氧还原活性随着聚合时间的延长先增加后降低,聚合时间为1000 s时所得改性石墨毡的两电子氧还原活性最高,H2O2生成速率达到29.40 mg/(L·cm2·h)。以PPy/GF-Na2SO4-1000为阴极材料构建电芬顿体系降解来自乙基纤维素生产过程的高盐有机废水,阴极电势为–0.55V时,8h后废水的化学需氧量(COD)可降至100mg/L以下,去除率达到88.8%。PPy/GF-Na2SO4-1000经过5次循环实验后活性无明显变化。
Graphite felt(GF) was modified by polypyrrole(PPy) via electrochemical oxidation polymerization, and the morphology, elemental composition and electrochemical properties of the polypyrrole-modified graphite felt electrodes were characterized by SEM, FTIR, XPS, LSV and EIS. The two-electron oxygen reduction activity of polypyrrole-modified graphite felt electrodes were characterized by H2O2 generation rate. The effects of supporting electrolyte and polymerization time on the structure and oxygen reduction performance of polypyrrole-modified graphite felt electrodes were investigated. The results showed that the structure of pyrrole nitrogen could be introduced on the surface of graphite felt by modification. The two-electron oxygen reduction activity of the modified electrode prepared with sodium sulfate as supporting electrolyte was the highest and a H2O2 generation rate was up to 24.82 mg/(L·cm2·h) at a cathode potential of –0.45 V. The two-electron oxygen reduction activity of the modified graphite felt electrodes increased first and then decreased with the increase of polymerization time. When the polymerization time was 1000 s, the obtained electrode(PPy/GF-Na2 SO4-1000) showed the highest H2O2 generation rate of 29.40 mg/(L·cm2·h). An electro-Fenton system was constructed with PPy/GF-Na2 SO4-1000 as cathode material to degrade the high salt organic wastewater from the ethyl cellulose process. The chemical oxygen demand(COD) of wastewater was reduced to less than 100 mg/L, and the removal rate was up to 88.8% after 8 hours reaction at a cathode potential of –0.55 V. PPy/GF-Na2 SO4-1000 had no significant activity loss after 5 cycles test.
作者
阮炽
刘长军
岳海荣
唐思扬
梁斌
鲁厚芳
RUAN Chi;LIU Changjun;YUE Hairong;TANG Siyang;LIANG Bin;LU Houfang(School of Chemical Engineering,Sichuan University,Chengdu 610065,Sichuan,China;Institute of New Energy and Low-carbon Technology,Sichuan University,Chengdu 610065,Sichuan,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2020年第9期1896-1903,1917,共9页
Fine Chemicals
基金
国家自然科学基金(21878190,21406146)
国家科技攻关计划(2018YFB0605700)。
关键词
电芬顿
石墨毡
聚吡咯
氧还原反应
高盐有机废水
有机电化学与工业
electro-Fenton
graphite felt
polypyrrole
oxygen reduction reaction
high salt organic wastewater
electro-organic chemistry and industry
