过渡金属氮化物因具有高的导电性、可调节的能带结构以及优异的稳定性,成为高性能析氢反应(HER)电催化剂的理想选择。然而,在合成过程中,过高或过低的氮化温度会导致材料的结构发生改变,进而影响其电化学活性。因此,调控适当的氮化温度...过渡金属氮化物因具有高的导电性、可调节的能带结构以及优异的稳定性,成为高性能析氢反应(HER)电催化剂的理想选择。然而,在合成过程中,过高或过低的氮化温度会导致材料的结构发生改变,进而影响其电化学活性。因此,调控适当的氮化温度至关重要。通过水热-煅烧工艺成功制备了自支撑Ni_(3)N/NiMoN异质结纳米片阵列(Ni_(3)N/NiMoN-450@CC)。采用XRD,SEM,XPS等测试手段对材料的形貌和组分进行表征,结果表明,Ni_(3)N/NiMoN异质结纳米片在碳布上均匀排列并形成阵列结构。通过线性扫描伏安法(LSV)和循环伏安法(CV)对材料的电化学性能进行观察,测试结果说明,Ni_(3)N/NiMoN-450@CC催化剂在碱性电解质中表现出良好的HER催化活性,电流密度为10 m A·cm-2时,其过电位为34 mV,并且在连续测试48 h后,电流密度几乎不变。展开更多
The effects of Ti/N ratio on the number densities of nano particles,the size of the prior austenite grain(PAG)and the toughness of the heat-affected zone(HAZ)of Mg-deoxidized steels were studied after high heat input ...The effects of Ti/N ratio on the number densities of nano particles,the size of the prior austenite grain(PAG)and the toughness of the heat-affected zone(HAZ)of Mg-deoxidized steels were studied after high heat input welding of 400 kJ/cm.With increasing the Ti/N ratio from 2.7 to 5.7,the cuboid nano-sized particles are formed,and their number density increases.The area fractions of ductile intragranular acicular ferrites(IAFs)have the highest value and the area fractions of brittle microstructures of ferrite side plates and upper bainites have the lowest value in TN30 steel.With the Ti/N ratio of about 3.0,the HAZ of steel plate has the best low-temperature toughness.With increasing the Ti/N ratio from 2.7 to 5.7,the PAG sizes after the high-temperature laser scanning confocal microscopy observation decrease linearly with increasing the number densities of nano-sized particles.The PAG size of TN30 steel is between 100 and 150μm,which is conducive to the nucleation of IAFs.展开更多
This study presents a novel approach,the Supercapacitor Microbial Electrolysis Cell(SCMEC),which utilizes a supercapacitor as an external power source to enhance the efficiency of autotrophic nitrogen removal in low C...This study presents a novel approach,the Supercapacitor Microbial Electrolysis Cell(SCMEC),which utilizes a supercapacitor as an external power source to enhance the efficiency of autotrophic nitrogen removal in low C/N ratio wastewater.The results demonstrated that the SC-MEC system,operating under anaerobic conditions and devoid of any organic carbon source,exhibited exceptional performance in ammonia oxidation and total nitrogen(TN)removal when solely relying on ammonia nitrogen as the electron donor.Operating at a voltage of 1.8 V with a capacitance capacity of 30 F,ammonium oxidation rated up to 56.51 mg/L/day and TN removal rated up to 54.64 mg/L/day,in which 97%of ammonium nitrogen was converted to gaseous nitrogen.Furthermore,the charging and discharging process of supercapacitors autonomously regulated the bipolar potentials.Cyclic voltammetry(CV)analysis showed the significantly enhanced electrochemical activity of the SCMEC system during the reaction process.Based on in-situ CV test results,itwas inferred that this enhancementwas associated with extracellular electron transfer mediators.Themicrobial community analysis revealed a process of synchronous nitrification and denitrification(SND)coupled with anammox,involvingmultiple genera,such as Candidatus Kuenenia,Nitrosomonas,Truepera,and Bosea.In conclusion,this study highlights the tremendous potential of SC-MEC in achieving efficient autotrophic nitrogen removal,offering more feasible and economical solutions for addressing low C/N water pollution issues.展开更多
文摘过渡金属氮化物因具有高的导电性、可调节的能带结构以及优异的稳定性,成为高性能析氢反应(HER)电催化剂的理想选择。然而,在合成过程中,过高或过低的氮化温度会导致材料的结构发生改变,进而影响其电化学活性。因此,调控适当的氮化温度至关重要。通过水热-煅烧工艺成功制备了自支撑Ni_(3)N/NiMoN异质结纳米片阵列(Ni_(3)N/NiMoN-450@CC)。采用XRD,SEM,XPS等测试手段对材料的形貌和组分进行表征,结果表明,Ni_(3)N/NiMoN异质结纳米片在碳布上均匀排列并形成阵列结构。通过线性扫描伏安法(LSV)和循环伏安法(CV)对材料的电化学性能进行观察,测试结果说明,Ni_(3)N/NiMoN-450@CC催化剂在碱性电解质中表现出良好的HER催化活性,电流密度为10 m A·cm-2时,其过电位为34 mV,并且在连续测试48 h后,电流密度几乎不变。
基金financially supported by the National Natural Science Foundation of China(52474361).
文摘The effects of Ti/N ratio on the number densities of nano particles,the size of the prior austenite grain(PAG)and the toughness of the heat-affected zone(HAZ)of Mg-deoxidized steels were studied after high heat input welding of 400 kJ/cm.With increasing the Ti/N ratio from 2.7 to 5.7,the cuboid nano-sized particles are formed,and their number density increases.The area fractions of ductile intragranular acicular ferrites(IAFs)have the highest value and the area fractions of brittle microstructures of ferrite side plates and upper bainites have the lowest value in TN30 steel.With the Ti/N ratio of about 3.0,the HAZ of steel plate has the best low-temperature toughness.With increasing the Ti/N ratio from 2.7 to 5.7,the PAG sizes after the high-temperature laser scanning confocal microscopy observation decrease linearly with increasing the number densities of nano-sized particles.The PAG size of TN30 steel is between 100 and 150μm,which is conducive to the nucleation of IAFs.
基金supported by the National Natural Science Foundation of China(No.31970106).
文摘This study presents a novel approach,the Supercapacitor Microbial Electrolysis Cell(SCMEC),which utilizes a supercapacitor as an external power source to enhance the efficiency of autotrophic nitrogen removal in low C/N ratio wastewater.The results demonstrated that the SC-MEC system,operating under anaerobic conditions and devoid of any organic carbon source,exhibited exceptional performance in ammonia oxidation and total nitrogen(TN)removal when solely relying on ammonia nitrogen as the electron donor.Operating at a voltage of 1.8 V with a capacitance capacity of 30 F,ammonium oxidation rated up to 56.51 mg/L/day and TN removal rated up to 54.64 mg/L/day,in which 97%of ammonium nitrogen was converted to gaseous nitrogen.Furthermore,the charging and discharging process of supercapacitors autonomously regulated the bipolar potentials.Cyclic voltammetry(CV)analysis showed the significantly enhanced electrochemical activity of the SCMEC system during the reaction process.Based on in-situ CV test results,itwas inferred that this enhancementwas associated with extracellular electron transfer mediators.Themicrobial community analysis revealed a process of synchronous nitrification and denitrification(SND)coupled with anammox,involvingmultiple genera,such as Candidatus Kuenenia,Nitrosomonas,Truepera,and Bosea.In conclusion,this study highlights the tremendous potential of SC-MEC in achieving efficient autotrophic nitrogen removal,offering more feasible and economical solutions for addressing low C/N water pollution issues.
