One approach to accelerate the stagnant kinetics of both the oxygen reduction and evolution reactions(ORR/OER)is to develop a rationally designed multiphase nanocomposite,where the functions arising from each of the c...One approach to accelerate the stagnant kinetics of both the oxygen reduction and evolution reactions(ORR/OER)is to develop a rationally designed multiphase nanocomposite,where the functions arising from each of the constituent phases,their interfaces,and the overall structure are properly controlled.Herein,we successfully synthesized an oxygen electrocatalyst consisting of Ni nanoparticles purposely interpenetrated into mesoporous NiO nanosheets(porous Ni/NiO).Benefiting from the contributions of the Ni and NiO phases,the well-established pore channels for charge transport at the interface between the phases,and the enhanced conductivity due to oxygen-deficiency at the pore edges,the porous Ni/NiO nanosheets show a potential of 1.49 V(10 mA cm^-2)for the OER and a half-wave potential of 0.76 V for the ORR,outperforming their noble metal counterparts.More significantly,a Zn-air battery employing the porous Ni/NiO nanosheets exhibits an initial charging-discharging voltage gap of 0.83 V(2 mA cm^-2),specific capacity of 853 mAh gZn^-1 at 20 mA cm^-2,and long-time cycling stability(120 h).In addition,the porous Ni/NiO-based solid-like Zn-air battery shows excellent electrochemical performance and flexibility,illustrating its great potential as a next-generation rechargeable power source for flexible electronics.展开更多
In order to well arrange active sites and avoid byproducts, the reasonable structured carrier nanocatalyst plays a crucial role in high catalytic performance, but still remains a challenge. Herein, the layered CuNi-Cu...In order to well arrange active sites and avoid byproducts, the reasonable structured carrier nanocatalyst plays a crucial role in high catalytic performance, but still remains a challenge. Herein, the layered CuNi-Cu_(2)O/NiAlO_(x) nanosheets have been constructed through hydrothermal synthesis followed by calcination and H_(2) reduction treatment process. The in-situ formed CuNi nanoalloys (NAs) and nano-Cu_(2)O were evenly distributed on the bilateral surface of layered NiAlOx nanosheets. Based on the planar structure of nanosheet, the synergy between catalytic active CuNi NAs and photocatalytic active nano-Cu_(2)O endows CuNi-Cu_(2)O/NiAlO_(x) nanosheets with rapid conversion efficiency for catalyzing p-nitrophenol (p-NP, 14 mg·L^(−1)) to p-aminophenol (p-AP) in 32 s with the reaction rate constant k up to 0.1779 s−1, and no obvious performance decay can be observed even over 27 cycles. Moreover, high concentration of p-NP at 10 and 20 g·L^(−1) could be reduced to p-AP within 14 and 20 min, respectively. Such designed nanoalloy/bimetal-oxide heterostructure can provide a solution for rapid conversion of aminoaromatics from nitroaromatics wastewater even at a large concentration range.展开更多
基金the National Natural Science Foundation of China(Grant Nos.11474137,11674143)the Fundamental Research Funds for the Central Universities(Grant No.Lzujbky-2019-cd02).
文摘One approach to accelerate the stagnant kinetics of both the oxygen reduction and evolution reactions(ORR/OER)is to develop a rationally designed multiphase nanocomposite,where the functions arising from each of the constituent phases,their interfaces,and the overall structure are properly controlled.Herein,we successfully synthesized an oxygen electrocatalyst consisting of Ni nanoparticles purposely interpenetrated into mesoporous NiO nanosheets(porous Ni/NiO).Benefiting from the contributions of the Ni and NiO phases,the well-established pore channels for charge transport at the interface between the phases,and the enhanced conductivity due to oxygen-deficiency at the pore edges,the porous Ni/NiO nanosheets show a potential of 1.49 V(10 mA cm^-2)for the OER and a half-wave potential of 0.76 V for the ORR,outperforming their noble metal counterparts.More significantly,a Zn-air battery employing the porous Ni/NiO nanosheets exhibits an initial charging-discharging voltage gap of 0.83 V(2 mA cm^-2),specific capacity of 853 mAh gZn^-1 at 20 mA cm^-2,and long-time cycling stability(120 h).In addition,the porous Ni/NiO-based solid-like Zn-air battery shows excellent electrochemical performance and flexibility,illustrating its great potential as a next-generation rechargeable power source for flexible electronics.
基金This work was supported by the National Natural Science Foundation of China(Nos.21771140,51979194,and 51771138)We really appreciate the support by the state key laboratory of fine chemicals,Dalian University of Technology(No.KF 2001).
文摘In order to well arrange active sites and avoid byproducts, the reasonable structured carrier nanocatalyst plays a crucial role in high catalytic performance, but still remains a challenge. Herein, the layered CuNi-Cu_(2)O/NiAlO_(x) nanosheets have been constructed through hydrothermal synthesis followed by calcination and H_(2) reduction treatment process. The in-situ formed CuNi nanoalloys (NAs) and nano-Cu_(2)O were evenly distributed on the bilateral surface of layered NiAlOx nanosheets. Based on the planar structure of nanosheet, the synergy between catalytic active CuNi NAs and photocatalytic active nano-Cu_(2)O endows CuNi-Cu_(2)O/NiAlO_(x) nanosheets with rapid conversion efficiency for catalyzing p-nitrophenol (p-NP, 14 mg·L^(−1)) to p-aminophenol (p-AP) in 32 s with the reaction rate constant k up to 0.1779 s−1, and no obvious performance decay can be observed even over 27 cycles. Moreover, high concentration of p-NP at 10 and 20 g·L^(−1) could be reduced to p-AP within 14 and 20 min, respectively. Such designed nanoalloy/bimetal-oxide heterostructure can provide a solution for rapid conversion of aminoaromatics from nitroaromatics wastewater even at a large concentration range.
