The structural, electronic, and magnetic properties of VSb in zincblende, and NiAs phases, VSb （001） film surfaces and its interfaces with GaSh （001） have been investigated within the framework of the density func...The structural, electronic, and magnetic properties of VSb in zincblende, and NiAs phases, VSb （001） film surfaces and its interfaces with GaSh （001） have been investigated within the framework of the density functional theory using the FPLAPW＋lo approach. The NiAs structure is more stable than the ZB phase, ZB VSb is found to a half-metallic ferromagnetic. The V-terminated surfaces retain the half-metallic character, while the half-metallicity is destroyed for Sb-terminated surfaces due to surface states, which originate from p electrons. The phase diagram obtained through the ab-initio atomistic thermodynamics shows that the formation energy of ZB VSb is about 0.1 Ryd. The half-metallicity character is also preserved at VSb/GaSb （001） interface. The conduction band minimum （CBM） of VSb in the minority spin case lies about 0.47 eV above that of GaSb, suggesting that the majority spin can be injected into GaSb without being flipped to the conduction bands of the minority spin.展开更多
Multifunctional catalysts that integrate high efficiency hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) catalytic activity in a single material are attractive for u...Multifunctional catalysts that integrate high efficiency hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) catalytic activity in a single material are attractive for unitized regenerative fuel cells and overall water splitting technologies. As the best-known HER and ORR electrocatalysts, Pt and its alloys have only moderate OER activity. Ruthenium and iridium oxides exhibit the highest OER activities but not as active as Pt for HER and ORR. Here, we proposed a general principle for achieving trifunctional electrocatalysis for three reactions in a single material. Using the newly-synthesized pyrazine-modified graphdiyne(PR-GDY) as an example, we demonstrated that the synergistic effect of the pyridinic nitrogen and anchored transition-metal(TM) single atoms renders highly-efficient HER/OER/ORR trifunctional electrocatalytic activity. For the Ni-doped PR-GDY, the overpotentials for HER, OER and ORR can be respectively as low as -0.05, 0.29 and 0.38 V, which are comparable or even superior to the best-known single-functional and bi-functional precious electrocatalysts.These computational results offer not only a promising trifunctional electrocatalyst but also a strategy for the design of multifunctional electrocatalysts.展开更多
文摘The structural, electronic, and magnetic properties of VSb in zincblende, and NiAs phases, VSb （001） film surfaces and its interfaces with GaSh （001） have been investigated within the framework of the density functional theory using the FPLAPW＋lo approach. The NiAs structure is more stable than the ZB phase, ZB VSb is found to a half-metallic ferromagnetic. The V-terminated surfaces retain the half-metallic character, while the half-metallicity is destroyed for Sb-terminated surfaces due to surface states, which originate from p electrons. The phase diagram obtained through the ab-initio atomistic thermodynamics shows that the formation energy of ZB VSb is about 0.1 Ryd. The half-metallicity character is also preserved at VSb/GaSb （001） interface. The conduction band minimum （CBM） of VSb in the minority spin case lies about 0.47 eV above that of GaSb, suggesting that the majority spin can be injected into GaSb without being flipped to the conduction bands of the minority spin.
基金supported by the Basic Research Project of Natural Science Foundation of Shandong Province(ZR2018ZB0751)the National Natural Science Foundation of China(11774201)the Taishan Scholar Program of Shandong Province。
文摘Multifunctional catalysts that integrate high efficiency hydrogen evolution reaction(HER), oxygen evolution reaction(OER) and oxygen reduction reaction(ORR) catalytic activity in a single material are attractive for unitized regenerative fuel cells and overall water splitting technologies. As the best-known HER and ORR electrocatalysts, Pt and its alloys have only moderate OER activity. Ruthenium and iridium oxides exhibit the highest OER activities but not as active as Pt for HER and ORR. Here, we proposed a general principle for achieving trifunctional electrocatalysis for three reactions in a single material. Using the newly-synthesized pyrazine-modified graphdiyne(PR-GDY) as an example, we demonstrated that the synergistic effect of the pyridinic nitrogen and anchored transition-metal(TM) single atoms renders highly-efficient HER/OER/ORR trifunctional electrocatalytic activity. For the Ni-doped PR-GDY, the overpotentials for HER, OER and ORR can be respectively as low as -0.05, 0.29 and 0.38 V, which are comparable or even superior to the best-known single-functional and bi-functional precious electrocatalysts.These computational results offer not only a promising trifunctional electrocatalyst but also a strategy for the design of multifunctional electrocatalysts.
