The interaction of poly(ethylene oxide)(PEO)with the ionic surfactants,sodium dodecylsulfate(SDS)and cetyltrimethylammonium chloride(CTAC)respectively,in aqueous solutions containing a certain concentration of NH_4Cl,...The interaction of poly(ethylene oxide)(PEO)with the ionic surfactants,sodium dodecylsulfate(SDS)and cetyltrimethylammonium chloride(CTAC)respectively,in aqueous solutions containing a certain concentration of NH_4Cl, is studied by the viscosity measurement.It has been found that the ion-dipole interaction between PEO and ionic surfactants is changed considerably by the organic salt.For anionic suffactant of SDS,the addition of NH_4Cl into solution strengthens the interaction between PEO and the headgroup o...展开更多
Influence of NH_4 Cl on the initial atmospheric corrosion of zinc was investigated viaquartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The resultsshow that NH_4 Cl can accelerate the initial corrosio...Influence of NH_4 Cl on the initial atmospheric corrosion of zinc was investigated viaquartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The resultsshow that NH_4 Cl can accelerate the initial corrosion of zinc. Mass gain increase withthe exposure time, but mass gain in the later doesn't change obviously due to theformation of the insoluble simonkolleite on zinc surface in the presence of NH_4 Cl.Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) wasused to characterize the corrosion products. Zn_5Cl_2(OH)_8·H_2O,(NH_4)_2ZnCl_4 andZnO are the corrosion products on zinc. Brief discussion on the mechanisms of at-mospheric corrosion of zinc in the presence of NH_4 Cl was introduced.展开更多
Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregation...Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N_(x) active sites are frequently observed in the commonly used pyrolysis procedure.Herein,single-atomic nickel(Ni)-based sheet-like electrocatalysts with abundant Ni-N_(4) active sites were created by using a novel ammonium chloride(NH_(4)Cl)-assited pyrolysis method.Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N_(4) structure.The addition of NH_(4)Cl optimized the mesopore size to 7-10 nm and increased the concentrations of pyridinic N(3.54 wt%)and Ni-N_(4)(3.33 wt%)species.The synergistic catalytic effect derived from Ni-N_(4) active sites and pyridinic N species achieved an outstanding CO_(2) RR performance,presenting a high CO Faradaic efficiency(FE_(CO))up to 98% and a large CO partial current density of 8.5 mA cm^(-2) at a low potential of-0.62 V vs.RHE.Particularly,the FE_(CO) maintains above 80% within a large potential range from -0.43 to -0.73 V vs.RHE.This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO_(2) conversion systems.展开更多
文摘The interaction of poly(ethylene oxide)(PEO)with the ionic surfactants,sodium dodecylsulfate(SDS)and cetyltrimethylammonium chloride(CTAC)respectively,in aqueous solutions containing a certain concentration of NH_4Cl, is studied by the viscosity measurement.It has been found that the ion-dipole interaction between PEO and ionic surfactants is changed considerably by the organic salt.For anionic suffactant of SDS,the addition of NH_4Cl into solution strengthens the interaction between PEO and the headgroup o...
文摘Influence of NH_4 Cl on the initial atmospheric corrosion of zinc was investigated viaquartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The resultsshow that NH_4 Cl can accelerate the initial corrosion of zinc. Mass gain increase withthe exposure time, but mass gain in the later doesn't change obviously due to theformation of the insoluble simonkolleite on zinc surface in the presence of NH_4 Cl.Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) wasused to characterize the corrosion products. Zn_5Cl_2(OH)_8·H_2O,(NH_4)_2ZnCl_4 andZnO are the corrosion products on zinc. Brief discussion on the mechanisms of at-mospheric corrosion of zinc in the presence of NH_4 Cl was introduced.
基金financially supported by the National Natural Science Foundation of China(Nos.21571159 and U1704256)the Natural Science Foundation of Henan Province,China(No.212300410299)the Doctoral Research Fund of Zhengzhou University of Light Industry(No.2018BSJJ024).
文摘Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N_(x) active sites are frequently observed in the commonly used pyrolysis procedure.Herein,single-atomic nickel(Ni)-based sheet-like electrocatalysts with abundant Ni-N_(4) active sites were created by using a novel ammonium chloride(NH_(4)Cl)-assited pyrolysis method.Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N_(4) structure.The addition of NH_(4)Cl optimized the mesopore size to 7-10 nm and increased the concentrations of pyridinic N(3.54 wt%)and Ni-N_(4)(3.33 wt%)species.The synergistic catalytic effect derived from Ni-N_(4) active sites and pyridinic N species achieved an outstanding CO_(2) RR performance,presenting a high CO Faradaic efficiency(FE_(CO))up to 98% and a large CO partial current density of 8.5 mA cm^(-2) at a low potential of-0.62 V vs.RHE.Particularly,the FE_(CO) maintains above 80% within a large potential range from -0.43 to -0.73 V vs.RHE.This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO_(2) conversion systems.
