Cathode material LiMn2O4 thin films were prepared by solution deposition followed by conventional thermal annealing （CTA） and rapid thermal annealing （RTA） using lithium acetate and manganese acetate as starting m...Cathode material LiMn2O4 thin films were prepared by solution deposition followed by conventional thermal annealing （CTA） and rapid thermal annealing （RTA） using lithium acetate and manganese acetate as starting materials. The phase and surface morphology identification was done by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were carried out by cyclic voltammetry, chargedischarge experiments, electrochemical impedance spectroscopy and potential step technique. The results show that both thin films are homogeneous and crack-free. Compared with the CTA derived thin films, the RTA derived ones with smaller grain size are more smooth and dense. The CTA and RTA derived LiMn2O4 thin films deliver the capacity of 34.5μAh/（cm^2·μm） and 38μAh/（cm^2·μm） ） and show the capacity loss of 0.050% and 0.037% per cycle after being cycled 100 times, respectively. The diffusion coefficient of lithium ion in the CTA derived LiMn2O4 thin-film electrode is 4.59×10^-11cm^2/s, and that of lithium ion in the RTA derived one is 3.86×10^-11cm^2/s.展开更多
The saccharification of cellulosic biomass to produce biofuels and chemicals is one of the most promising industries for gree n-power production and sustainable development.Cellulase is the core component in the sacch...The saccharification of cellulosic biomass to produce biofuels and chemicals is one of the most promising industries for gree n-power production and sustainable development.Cellulase is the core component in the saccharification process.Simple and efficient assay method to determine cellulase activity in saccharification is thus highly required.In this work,a boronate-affinity surface based renewable and ultrasensitive electrochemical sensor for cellulase activity determination has been fabricated.Through bo ronate-sugar interaction,celluloses are attached to the electrode surface,forming the cellulose na nonetwork at the sensing interface.Cellulase degradation can lead to the variation of electrochemical impedance.Thus,electrochemical impedance signal can reflect the cellulase activity.Importantly,via fully utilizing the boronate-affinity chemistry that enables reversible fabrication of cellulose nanonetwork,a renewable sensing surface has been firstly constructed for cellulase activity assay.Thanks to interfacial diffusion process of electrochemical sensor,the product inhibitory effect in the cellulase activity assays can be circumvented.The proposed electrochemical sensor is ultrasensitive for label-free cellulase activity detection with a very simple fabrication process,showing great potential for activity screen of new enzymes in saccharification conversion.展开更多
基金the Hunan Provincial Natural Science Foundation of China （No. 04JJ40038） the Hunan Provincial Education Department （No. 04C475）.
文摘Cathode material LiMn2O4 thin films were prepared by solution deposition followed by conventional thermal annealing （CTA） and rapid thermal annealing （RTA） using lithium acetate and manganese acetate as starting materials. The phase and surface morphology identification was done by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were carried out by cyclic voltammetry, chargedischarge experiments, electrochemical impedance spectroscopy and potential step technique. The results show that both thin films are homogeneous and crack-free. Compared with the CTA derived thin films, the RTA derived ones with smaller grain size are more smooth and dense. The CTA and RTA derived LiMn2O4 thin films deliver the capacity of 34.5μAh/（cm^2·μm） and 38μAh/（cm^2·μm） ） and show the capacity loss of 0.050% and 0.037% per cycle after being cycled 100 times, respectively. The diffusion coefficient of lithium ion in the CTA derived LiMn2O4 thin-film electrode is 4.59×10^-11cm^2/s, and that of lithium ion in the RTA derived one is 3.86×10^-11cm^2/s.
基金supported by the National Natural Science Foundation of China (Nos.21625502,21705079,21671105 and 21974070)the Natural Science Foundation of Jiangsu Province (Nos.BK20192008 and BK20171033)the financial support from the PAPD。
文摘The saccharification of cellulosic biomass to produce biofuels and chemicals is one of the most promising industries for gree n-power production and sustainable development.Cellulase is the core component in the saccharification process.Simple and efficient assay method to determine cellulase activity in saccharification is thus highly required.In this work,a boronate-affinity surface based renewable and ultrasensitive electrochemical sensor for cellulase activity determination has been fabricated.Through bo ronate-sugar interaction,celluloses are attached to the electrode surface,forming the cellulose na nonetwork at the sensing interface.Cellulase degradation can lead to the variation of electrochemical impedance.Thus,electrochemical impedance signal can reflect the cellulase activity.Importantly,via fully utilizing the boronate-affinity chemistry that enables reversible fabrication of cellulose nanonetwork,a renewable sensing surface has been firstly constructed for cellulase activity assay.Thanks to interfacial diffusion process of electrochemical sensor,the product inhibitory effect in the cellulase activity assays can be circumvented.The proposed electrochemical sensor is ultrasensitive for label-free cellulase activity detection with a very simple fabrication process,showing great potential for activity screen of new enzymes in saccharification conversion.
