CuS nanoplatelets arrays grown on graphene nanosheets are successfully synthesized via a facile lowtemperature solvothermal reaction with graphene oxide（GO）, CH;CSNH;and Cu（CH;COO）;·H;O as the reactants. CH;C...CuS nanoplatelets arrays grown on graphene nanosheets are successfully synthesized via a facile lowtemperature solvothermal reaction with graphene oxide（GO）, CH;CSNH;and Cu（CH;COO）;·H;O as the reactants. CH;CSNH;plays an important role in being the reducing agent for GO and the sulfur source of CuS. Supercapacitive performance of the graphene/CuS nanocomposite as active electrode materials has been evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy measurements. The results indicate that graphene/CuS electrode delivers a high capacitance of 497.8 F g;at a current density of 0.2 A g;, which outperforms bare CuS electrode. This excellent performance is ascribed to the short diffusion path and large surface area of the unique hierarchical nanostructure with nanoflakes building blocks for bulk accessibility of faradaic reaction.展开更多
Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-i...Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-ion batteries.However,their practical deployment has long been plagued by the infamous“shuttle effect”of soluble Li polysulfides(LiPSs)and the rampant growth of Li dendrites.Therefore,it is important to specifically elucidate the solvation structure in the Li-S system and systematically summarize the feasibility strategies that can simultaneously suppress the shuttle effect and the growth of Li dendrites for practical applications.This review attempts to achieve this goal.In this review,we first introduce the importance of developing Li-S batteries and highlight the key challenges.Then,we revisit the working principles of Li-S batteries and underscore the fundamental understanding of LiPSs.Next,we summarize some representative characterization techniques and theoretical calculations applied to characterize the solvation structure of LiPSs.Afterward,we overview feasible designing strategies that can simultaneously suppress the shuttle effect of soluble LiPSs and the growth of Li dendrites.Finally,we conclude and propose personal insights and perspectives on the future development of Li-S batteries.We envisage that this timely review can provide some inspiration to build better Li-S batteries for promoting practical applications.展开更多
An in situ chemical synthesis approach has been employed to prepare an Ag-chemically converted graphene (CCG) nanocomposite. The reduction of graphene oxide sheets was accompanied by generation of Ag nanoparticles. Th...An in situ chemical synthesis approach has been employed to prepare an Ag-chemically converted graphene (CCG) nanocomposite. The reduction of graphene oxide sheets was accompanied by generation of Ag nanoparticles. The structure and composition of the nanocomposites were confirmed by means of transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray diffraction. TEM and AFM results suggest a homogeneous distribution of Ag nanoparticles (5-10 nm in size) on CCG sheets. The intensities of the Raman signals of CCG in such nanocomposites are greatly increased by the attached silver nanoparticles, i.e., there is surface-enhanced Raman scattering activity. In addition, it was found that the antibacterial activity of free Ag nanoparticles is retained in the nanocomposites, which suggests they can be used as graphene-based biomaterials.展开更多
Nowadays,two-dimensional transition metal chalcogenides have become attractive materials for flexible wearable devices because of their intriguing chemistry characteristics and sensitivity to external stimuli.However,...Nowadays,two-dimensional transition metal chalcogenides have become attractive materials for flexible wearable devices because of their intriguing chemistry characteristics and sensitivity to external stimuli.However,the growth of two-dimensional materials on polymer surfaces is generally carried out by the time-consuming and costly chemical vapor deposition method.Reducing the manufacturing and integration costs while improving the device performance remains to be challenging.Herein,we report a simple liquid metal-assisted hydrothermal method for the growth of two-dimensional nanomaterials on the polymer surface.Specifically,a layer of liquid metal was coated on commercial tape,while layered cobalt sulfide was grown on its surface by a simple one-step hydrothermal method.Different kinds of flexible sensors can be prepared,such as bending sensor,pressure sensor,humidity sensor,which can be used to detect motion,writing,breathing,other signals.This strategy can also be assigned to sensing signals on different objects,which may further expand and enrich the application of twodimensional materials in sensing.展开更多
基金supported by the General Project of Anhui Provincial Education Department(TSKJ2016B13)Key Project of Anhui Provincial Education Department(KJ2018A0104)the Startup Fund from AHPU(2015YQQ007)
文摘CuS nanoplatelets arrays grown on graphene nanosheets are successfully synthesized via a facile lowtemperature solvothermal reaction with graphene oxide（GO）, CH;CSNH;and Cu（CH;COO）;·H;O as the reactants. CH;CSNH;plays an important role in being the reducing agent for GO and the sulfur source of CuS. Supercapacitive performance of the graphene/CuS nanocomposite as active electrode materials has been evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy measurements. The results indicate that graphene/CuS electrode delivers a high capacitance of 497.8 F g;at a current density of 0.2 A g;, which outperforms bare CuS electrode. This excellent performance is ascribed to the short diffusion path and large surface area of the unique hierarchical nanostructure with nanoflakes building blocks for bulk accessibility of faradaic reaction.
基金financially supported by the National Natural Science Foundation of China(51972064 and 52222315)
文摘Rechargeable lithium-sulfur(Li-S)batteries,featuring high energy density,low cost,and environmental friendliness,have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li-ion batteries.However,their practical deployment has long been plagued by the infamous“shuttle effect”of soluble Li polysulfides(LiPSs)and the rampant growth of Li dendrites.Therefore,it is important to specifically elucidate the solvation structure in the Li-S system and systematically summarize the feasibility strategies that can simultaneously suppress the shuttle effect and the growth of Li dendrites for practical applications.This review attempts to achieve this goal.In this review,we first introduce the importance of developing Li-S batteries and highlight the key challenges.Then,we revisit the working principles of Li-S batteries and underscore the fundamental understanding of LiPSs.Next,we summarize some representative characterization techniques and theoretical calculations applied to characterize the solvation structure of LiPSs.Afterward,we overview feasible designing strategies that can simultaneously suppress the shuttle effect of soluble LiPSs and the growth of Li dendrites.Finally,we conclude and propose personal insights and perspectives on the future development of Li-S batteries.We envisage that this timely review can provide some inspiration to build better Li-S batteries for promoting practical applications.
文摘An in situ chemical synthesis approach has been employed to prepare an Ag-chemically converted graphene (CCG) nanocomposite. The reduction of graphene oxide sheets was accompanied by generation of Ag nanoparticles. The structure and composition of the nanocomposites were confirmed by means of transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray diffraction. TEM and AFM results suggest a homogeneous distribution of Ag nanoparticles (5-10 nm in size) on CCG sheets. The intensities of the Raman signals of CCG in such nanocomposites are greatly increased by the attached silver nanoparticles, i.e., there is surface-enhanced Raman scattering activity. In addition, it was found that the antibacterial activity of free Ag nanoparticles is retained in the nanocomposites, which suggests they can be used as graphene-based biomaterials.
基金the National Natural Science Foundation of China(No.51972064).
文摘Nowadays,two-dimensional transition metal chalcogenides have become attractive materials for flexible wearable devices because of their intriguing chemistry characteristics and sensitivity to external stimuli.However,the growth of two-dimensional materials on polymer surfaces is generally carried out by the time-consuming and costly chemical vapor deposition method.Reducing the manufacturing and integration costs while improving the device performance remains to be challenging.Herein,we report a simple liquid metal-assisted hydrothermal method for the growth of two-dimensional nanomaterials on the polymer surface.Specifically,a layer of liquid metal was coated on commercial tape,while layered cobalt sulfide was grown on its surface by a simple one-step hydrothermal method.Different kinds of flexible sensors can be prepared,such as bending sensor,pressure sensor,humidity sensor,which can be used to detect motion,writing,breathing,other signals.This strategy can also be assigned to sensing signals on different objects,which may further expand and enrich the application of twodimensional materials in sensing.
