Few-layers WS_(2) was obtained through unique chemical liquid exfoliation of commercial WS_(2).Results showed that after the exfoliation process,the thickness of WS_(2) reduced significantly.Moreover,the NiFe_(2)O_(4)...Few-layers WS_(2) was obtained through unique chemical liquid exfoliation of commercial WS_(2).Results showed that after the exfoliation process,the thickness of WS_(2) reduced significantly.Moreover,the NiFe_(2)O_(4) nanosheets/WS_(2) composite was successfully synthesized through a facile hydrothermal method at 180°C,and then proven by the analyses of field emission scanning electron microscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The composite showed a high specific surface area of 86.89 m^(2)·g^(−1) with an average pore size of 3.13 nm.Besides,in the threeelectrode electrochemical test,this composite exhibited a high specific capacitance of 878.04 F·g^(−1) at a current density of 1 A·g^(−1),while in the two-electrode system,the energy density of the composite could reach 25.47 Wh·kg^(−1) at the power density of 70 W·kg^(−1) and maintained 13.42 Wh·kg^(−1) at the higher power density of 7000 W·kg^(−1).All the excellent electrochemical performances demonstrate that the NiFe_(2)O_(4) nanosheets/WS_(2) composite is an excellent candidate for supercapacitor applications.展开更多
Due to their excellent physical and chemical properties,boron nitride nanosheets(BNNSs)have shown great application potential in many fields.However,the difficulty in scalable preparation of large-size BNNSs is still ...Due to their excellent physical and chemical properties,boron nitride nanosheets(BNNSs)have shown great application potential in many fields.However,the difficulty in scalable preparation of large-size BNNSs is still the current factor that limits this.Herein,a simple yet efficient microwave-assisted chemical exfoliation strategy is proposed to realize scalable preparation of BNNSs by using perchloric acid as the edge modifier and intercalation agent of h-BN.The as-obtained BNNSs behave a thin-layered structure(average thickness of 3.9 nm)with a high yield of~16%.Noteworthy,the size of BNNSs is maintained to the greatest extent so as to realize the preparation of BNNSs with ultra-large size(up to 7.1μm),which is the largest so far obtained for the top-down exfoliated BNNSs.Benefiting from the large size,it can significantly improve the thermal diffusion coefficient and the thermal conductivity of polyvinyl alcohol by 51 and 62 times respectively,both showing a higher value than the one previously reported.This demonstrates that the prepared BNNSs have great promise in enhancing the thermal conductivity of polymer materials.展开更多
基金supported by Major Basic Research Projects of Shandong Natural Science Foundation(ZR2018ZB0104)Science and Technology Development Project of Shandong Province(2016GGX102003 and 2017GGX20105)Natural Science Foundation of Shandong Province(ZR2017BEM032).
文摘Few-layers WS_(2) was obtained through unique chemical liquid exfoliation of commercial WS_(2).Results showed that after the exfoliation process,the thickness of WS_(2) reduced significantly.Moreover,the NiFe_(2)O_(4) nanosheets/WS_(2) composite was successfully synthesized through a facile hydrothermal method at 180°C,and then proven by the analyses of field emission scanning electron microscopy,X-ray diffraction,and X-ray photoelectron spectroscopy.The composite showed a high specific surface area of 86.89 m^(2)·g^(−1) with an average pore size of 3.13 nm.Besides,in the threeelectrode electrochemical test,this composite exhibited a high specific capacitance of 878.04 F·g^(−1) at a current density of 1 A·g^(−1),while in the two-electrode system,the energy density of the composite could reach 25.47 Wh·kg^(−1) at the power density of 70 W·kg^(−1) and maintained 13.42 Wh·kg^(−1) at the higher power density of 7000 W·kg^(−1).All the excellent electrochemical performances demonstrate that the NiFe_(2)O_(4) nanosheets/WS_(2) composite is an excellent candidate for supercapacitor applications.
基金Projects 52172052 and 51872253 supported by the National Natural Science Foundation of ChinaProject E2019203480 supported by the Hebei Natural Science Foundation of China.
文摘Due to their excellent physical and chemical properties,boron nitride nanosheets(BNNSs)have shown great application potential in many fields.However,the difficulty in scalable preparation of large-size BNNSs is still the current factor that limits this.Herein,a simple yet efficient microwave-assisted chemical exfoliation strategy is proposed to realize scalable preparation of BNNSs by using perchloric acid as the edge modifier and intercalation agent of h-BN.The as-obtained BNNSs behave a thin-layered structure(average thickness of 3.9 nm)with a high yield of~16%.Noteworthy,the size of BNNSs is maintained to the greatest extent so as to realize the preparation of BNNSs with ultra-large size(up to 7.1μm),which is the largest so far obtained for the top-down exfoliated BNNSs.Benefiting from the large size,it can significantly improve the thermal diffusion coefficient and the thermal conductivity of polyvinyl alcohol by 51 and 62 times respectively,both showing a higher value than the one previously reported.This demonstrates that the prepared BNNSs have great promise in enhancing the thermal conductivity of polymer materials.