In this work,a simple two-step electrodeposition was employed to prepare PPy-Cu/GF(PPy,polypyrrole;GF,graphite felt)composite cathodes for the nitrate reduction.Characterized results revealed that the introduction of ...In this work,a simple two-step electrodeposition was employed to prepare PPy-Cu/GF(PPy,polypyrrole;GF,graphite felt)composite cathodes for the nitrate reduction.Characterized results revealed that the introduction of PPy as an intermediate layer resulted in the transformation of both granular and dendritic Cu in form of Cu^(+)/Cu^(0),Cu^(2+)on the electrode surface.The NO_(3)^(-)-N of 50 mg·L^(-1)was almost completely removed(99.01%)using the PPy-Cu/GF cathode under the optimum condition,which is obviously higher than the GF,PPy/GF and Cu/GF electrodes.NO_(3)^(-)-N removal was slightly affected over the pH scale of 3.0 e11.0,whereas increasing the current density from 10 to 25 mA·cm^(-2)boosted the reduction of NO_(3)^(-)-N.At a Cl-concentration of 2000 mg·L^(-1),the removal of NO_(3)^(-)-N was slightly reduced,while the selectivity for N_(2)increased dramatically due to the active chlorine could oxidize NH_(4)^(+)-N to N_(2).Meanwhile,PPy-Cu/GF cathode exhibits an average removal rate of 97.83%within 12 cycles,highlighting its potential for application in actual water bodies.The EPR analysis and the active species trapping experiment confirmed that the nitrate reduction on the PPy-Cu/GF cathode mainly relies on direct reduction mediated by electron transfer,while*H influences the reduction of nitrite to ammonia.展开更多
基金supported by the National Natural Science Foundation of China(22076111)Key Research and Development Program of Shaanxi(2024 GX-YBXM-427),China.
文摘In this work,a simple two-step electrodeposition was employed to prepare PPy-Cu/GF(PPy,polypyrrole;GF,graphite felt)composite cathodes for the nitrate reduction.Characterized results revealed that the introduction of PPy as an intermediate layer resulted in the transformation of both granular and dendritic Cu in form of Cu^(+)/Cu^(0),Cu^(2+)on the electrode surface.The NO_(3)^(-)-N of 50 mg·L^(-1)was almost completely removed(99.01%)using the PPy-Cu/GF cathode under the optimum condition,which is obviously higher than the GF,PPy/GF and Cu/GF electrodes.NO_(3)^(-)-N removal was slightly affected over the pH scale of 3.0 e11.0,whereas increasing the current density from 10 to 25 mA·cm^(-2)boosted the reduction of NO_(3)^(-)-N.At a Cl-concentration of 2000 mg·L^(-1),the removal of NO_(3)^(-)-N was slightly reduced,while the selectivity for N_(2)increased dramatically due to the active chlorine could oxidize NH_(4)^(+)-N to N_(2).Meanwhile,PPy-Cu/GF cathode exhibits an average removal rate of 97.83%within 12 cycles,highlighting its potential for application in actual water bodies.The EPR analysis and the active species trapping experiment confirmed that the nitrate reduction on the PPy-Cu/GF cathode mainly relies on direct reduction mediated by electron transfer,while*H influences the reduction of nitrite to ammonia.
