Multifunctional carbon encapsulated Ni@NiO nanocomposites（Ni@NiO@C） were synthesized for applications in oxygen reduction reactions（ORR）,oxygen evolution reactions（OER） and lithium-ion batteries（LIB）. The morp...Multifunctional carbon encapsulated Ni@NiO nanocomposites（Ni@NiO@C） were synthesized for applications in oxygen reduction reactions（ORR）,oxygen evolution reactions（OER） and lithium-ion batteries（LIB）. The morphology was investigated via SEM and TEM,suggesting that the Ni@NiO@C nanocomposites have uniform and spherical core-shell structures. When the Ni@NiO@C nanocomposite is used as the catalyst in ORR,90% of the initial current density can be maintained after 15h in O_2-saturated 0.1 mol L^-1 KOH at 0.3 V under a rotation speed of 1600rpm.As a catalyst for OER,the highest activity overpotential of the Ni@NiO@C nanocomposite electrocatalyst is 380 mV（vs.RHE） under the current density of 10 mA cm^（-2）,and the Tafel slope was calculated to be 55 mV dec^-1 by linear fitting. Electrochemical performances of the Ni@NiO@C nanocomposites used as LIB electrodes exhibited a long cycling life with a high capacity of 750 mA h g^-1 after 400 cycles under 200 mA g^-1.展开更多
The severe bulk recombination and sluggish oxygen evolution reaction(OER)dynamics of photoanodes severely restrict the application of photoelectrochemical(PEC)devices.To solve these two problems,crystallographic facet...The severe bulk recombination and sluggish oxygen evolution reaction(OER)dynamics of photoanodes severely restrict the application of photoelectrochemical(PEC)devices.To solve these two problems,crystallographic facet orientation and cocatalyst emergence with a high-quality photoanode/cocatalyst interface were realized through an air annealing-assisted strategy to treat atomic layer deposition(ALD)-modified SnSnanosheet arrays.Based on experimental observations and theoretical calculations,the reduced(001)crystal facet of SnSdecreases the recombination of photogenerated carriers in the bulk and improves the carrier separation of the photoanode.Moreover,the unexpectedly formed ZnTiOSfilm decreases the overpotential of the surface OER,reduces interface recombination,and extends the carrier lifetime.These synergistic effects lead to significantly enhanced PEC performance,with a high photocurrent density of 1.97 mA cm^(-2)at 1.23 V vs.reversible hydrogen electrode(RHE)and a low onset potential of 0.21 V vs.RHE,which are superior to reported mostly SnS-based photoanodes.展开更多
基金supported by the National Natural Science Foundation of China (51571172,51672240,51571171,and 11404280)the Natural Science Foundation for Distinguished Young Scholars of Hebei Province (E2017203095)+1 种基金the Natural Science Foundation of Hebei Province (E2016203484 and A2015203337)the Research Program of the College Science & Technology of Hebei Province (ZD2017083 and QN2014047)
文摘Multifunctional carbon encapsulated Ni@NiO nanocomposites（Ni@NiO@C） were synthesized for applications in oxygen reduction reactions（ORR）,oxygen evolution reactions（OER） and lithium-ion batteries（LIB）. The morphology was investigated via SEM and TEM,suggesting that the Ni@NiO@C nanocomposites have uniform and spherical core-shell structures. When the Ni@NiO@C nanocomposite is used as the catalyst in ORR,90% of the initial current density can be maintained after 15h in O_2-saturated 0.1 mol L^-1 KOH at 0.3 V under a rotation speed of 1600rpm.As a catalyst for OER,the highest activity overpotential of the Ni@NiO@C nanocomposite electrocatalyst is 380 mV（vs.RHE） under the current density of 10 mA cm^（-2）,and the Tafel slope was calculated to be 55 mV dec^-1 by linear fitting. Electrochemical performances of the Ni@NiO@C nanocomposites used as LIB electrodes exhibited a long cycling life with a high capacity of 750 mA h g^-1 after 400 cycles under 200 mA g^-1.
基金support from the National Key Research and Development Program of China(2021YFA1500800)the National Natural Science Foundation of China(52025028)+1 种基金the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionssupport of the National Natural Science Foundation of China(21973006)。
文摘The severe bulk recombination and sluggish oxygen evolution reaction(OER)dynamics of photoanodes severely restrict the application of photoelectrochemical(PEC)devices.To solve these two problems,crystallographic facet orientation and cocatalyst emergence with a high-quality photoanode/cocatalyst interface were realized through an air annealing-assisted strategy to treat atomic layer deposition(ALD)-modified SnSnanosheet arrays.Based on experimental observations and theoretical calculations,the reduced(001)crystal facet of SnSdecreases the recombination of photogenerated carriers in the bulk and improves the carrier separation of the photoanode.Moreover,the unexpectedly formed ZnTiOSfilm decreases the overpotential of the surface OER,reduces interface recombination,and extends the carrier lifetime.These synergistic effects lead to significantly enhanced PEC performance,with a high photocurrent density of 1.97 mA cm^(-2)at 1.23 V vs.reversible hydrogen electrode(RHE)and a low onset potential of 0.21 V vs.RHE,which are superior to reported mostly SnS-based photoanodes.
