Synthesis Of Inorganic Nanomaterials And The Study Of Their Electrochemical Performance

In recent years, with the increasing threats to the world’s collective energysecurity and environment et al., more attention has been focused on addressing thesecritical challenges and driving global research to develop new technology for energystorage and conservation, high performance sensitive sensors, and so on. Owing totheir peculiar physical and chemical properties, nanomaterials show great potentialapplication in sensors, supercapacitors, lithium ion batteries and other fields. Theexploration of a simple and practical approach for synthesis of nanomaterials andnovel properties of nanomaterials is at the forefront of research in internationalmaterials industry. In this paper, we demonstrated the classification, characteristics,preparation of nanomaterials and their applications in biosensors and supercapacitors.We further provided information about the progress of the active materials inbiosensors and supercapacitors briefly. Based on the above points, we synthesizedseveral nanomaterials and characterized their morphology and constituent. We furtherstudied their electrochemical performance. The detailed materials are summarized asfollows:In chapter2, a non-enzymatic hydrogen peroxide (H2O2) sensor was successfullyrealized from MnO2ultrathin nanosheets, which were synthesized by a simplesolution phase approach. The MnO2ultrathin nanosheets based electrodes exhibitedhigh electrochemical activity for the detection of H2O2in phosphate buffer solution atan applied potential of+0.7V. The non-enzymatic biosensors showed a wide linearrange (5×106M to3.5×103M)，a low detection limit (1.5μM) and high sensitivity(130.56μAmM-1cm-2) towards H2O2, which could be attributed to the high surfacearea and electrocatalytic activity of MnO2ultrathin nanosheets. These resultsdemonstrate that such MnO2ultrathin nanosheets offer great promise fornon-enzymatic biosensor applications.In chapter3, a facile and low-cost approach was developed to fabricate the large-scale growth of nickel sulfide arrays via hydrothermal route-assisted sulfurization ofNi foam. The obtained Ni3S2arrays exhibited excellent supercapacitor performance, aspecific capacitance of1.342F/cm2at a current density of15mA/cm2was obtainedand retaining almost93.6%of the maximum capacitance after3000cycles. Thestrategy of self-sulfurization is promising for application of the construction othernanoarchitectured sulfide arrays for electrochemical applications.In chapter4, a facile hydrothermal method was developed for large-scale production of one-dimensional (1D) nickel cobaltate (NiCo2O4) nanowire arrays on Nifoam. Based on the morphology evolution upon reaction time, the possible growthprocess is proposed. When it was used for supercapacitor testing, a specificcapacitance of1.532F/cm2at a current density of2mA/cm2was obtained. Even after3000cycles at a current density of10mA/cm2,93.8%of the maximum capacitanceretention could be achieved. Our results show this1D nickel cobaltite is promising forsupercapacitor application.