Designing cost-effective and high-performance carbon-based oxygen reduction reaction(ORR)electrocatalysts is crucial in the development of Zn-air batteries(ZABs).In this study,a facile one-pot synthesis approach is en...Designing cost-effective and high-performance carbon-based oxygen reduction reaction(ORR)electrocatalysts is crucial in the development of Zn-air batteries(ZABs).In this study,a facile one-pot synthesis approach is engineered to construct Zn/Co-N-C carbonaceous polyhedrons interconnected with self-catalyzed-grown carbon nanotubes(CNTs)from zeolitic imidazolium frameworks linked with graphene oxide nanosheets.The special N-doped threedimensional(3 D)carbon matrix allows manipulating the exposure of active sites and the synergistic interaction between metal nanoparticles and CNTs.The as-synthesized catalyst features impressive ORR activity in 0.1 mol L^(-1)KOH(E_(1/2)=0.83 V)and 0.5 mol L^(-1)H_(2)SO_(4)(E_(1/2)=0.73 V),satisfactory cycling stability and methanol resistance comparable to those of the benchmark Pt/C catalyst(E_(1/2)=0.80 V in 0.1 mol L^(-1)KOH,E_(1/2)=0.75 V in 0.5 mol L^(-1)H_(2)SO_(4)).Furthermore,the asestablished ZAB demonstrates a competitive peak power density(90 mW cm^(-2))and prominent long-term stability,which are better than those of devices based on the commercial Pt/C catalyst(82 mW cm^(-2)).This work provides promising guidance for fabricating highly effective ORR catalysts with in situ formed CNTs,which can be applied in portable ZABrelated devices.展开更多
Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via...Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via interfacial crosslinking with 1-aminopyrene(AP) and 1-pyrenebutyrat(PB) small molecules. The AP/PB-GP with thickness of over ten micrometer delivers a record-high toughness(~69.67 ± 15.3 MJ m^(-3) in average), simultaneously with superior strength(close to 1 GPa), allowing an impressive specific penetration energy absorption(~0.17 MJ kg^(-1)) at high impact velocities when used for ballistic impact protection. Detailed interfacial and structural analysis reveals that the reinforcement is synergistically determined by π-π interaction and H-bonding linkage between adjacent graphene lamellae. Especially, the defective pores within the graphene platelets benefit the favorable adsorption of the pyrene-containing molecules, which imperatively maximizes the interfacial binding, facilitating deflecting crack and plastic deformation under loading. Density functional theory simulation suggests that the coupling between the polar functional groups, e.g., –COOH, at the edges of graphene platelets and –NH_(2) and –COOH of AP/PB are critical to the formation of hydrogen bonding network.展开更多
基金supported by the National Natural Science Foundation of China(51872076 and U1804255)the Program for Innovative Research Team of Henan Scientific Committee(CXTD2014033)+1 种基金the Project of Central Plains Science and Technology Innovation Leading Talents of Henan Province(194200510001)the Scientific and Technological Research Project of Henan province(212102210651)。
文摘Designing cost-effective and high-performance carbon-based oxygen reduction reaction(ORR)electrocatalysts is crucial in the development of Zn-air batteries(ZABs).In this study,a facile one-pot synthesis approach is engineered to construct Zn/Co-N-C carbonaceous polyhedrons interconnected with self-catalyzed-grown carbon nanotubes(CNTs)from zeolitic imidazolium frameworks linked with graphene oxide nanosheets.The special N-doped threedimensional(3 D)carbon matrix allows manipulating the exposure of active sites and the synergistic interaction between metal nanoparticles and CNTs.The as-synthesized catalyst features impressive ORR activity in 0.1 mol L^(-1)KOH(E_(1/2)=0.83 V)and 0.5 mol L^(-1)H_(2)SO_(4)(E_(1/2)=0.73 V),satisfactory cycling stability and methanol resistance comparable to those of the benchmark Pt/C catalyst(E_(1/2)=0.80 V in 0.1 mol L^(-1)KOH,E_(1/2)=0.75 V in 0.5 mol L^(-1)H_(2)SO_(4)).Furthermore,the asestablished ZAB demonstrates a competitive peak power density(90 mW cm^(-2))and prominent long-term stability,which are better than those of devices based on the commercial Pt/C catalyst(82 mW cm^(-2)).This work provides promising guidance for fabricating highly effective ORR catalysts with in situ formed CNTs,which can be applied in portable ZABrelated devices.
基金supported by the National Natural Science Foundation of China (51772282,51972299)funding from Hefei Center for Physical Science and Technology。
文摘Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via interfacial crosslinking with 1-aminopyrene(AP) and 1-pyrenebutyrat(PB) small molecules. The AP/PB-GP with thickness of over ten micrometer delivers a record-high toughness(~69.67 ± 15.3 MJ m^(-3) in average), simultaneously with superior strength(close to 1 GPa), allowing an impressive specific penetration energy absorption(~0.17 MJ kg^(-1)) at high impact velocities when used for ballistic impact protection. Detailed interfacial and structural analysis reveals that the reinforcement is synergistically determined by π-π interaction and H-bonding linkage between adjacent graphene lamellae. Especially, the defective pores within the graphene platelets benefit the favorable adsorption of the pyrene-containing molecules, which imperatively maximizes the interfacial binding, facilitating deflecting crack and plastic deformation under loading. Density functional theory simulation suggests that the coupling between the polar functional groups, e.g., –COOH, at the edges of graphene platelets and –NH_(2) and –COOH of AP/PB are critical to the formation of hydrogen bonding network.
