Preparation Of Biomass Dioscorea-derived Carbon Nanoaerogel And Its Applications Study In Electrochemistry

With the crisis of environmental pollution caused by the continuous consumption of non-renewable energy,researchers have gradually paid more attention to clean energy.Ethanol,as a renewable energy source,has been involved in the creation of new types of energy product with good economic benefits.For example,ethanol gasoline is currently the focus of renewable energy development in the world.Over the past two decades,scientific research that directly uses ethanol as a form of energy has grown exponentially.Besides,new energy sources derived from ethanol like biofuel cells?BFCs?are also one of the hot topics of scientific research.Enzyme biofuel cells?EBFCs?,as a type of BFCs,are green new energy devices that directly or indirectly use enzymes to perform redox reactions under electrochemical catalysis to convert chemical energy into electrical energy.On the other hand,the precise detection of ethanol molecules is particularly important in various fields such as forensic science,clinical analysis,and other industrial fields.Carbon nanomaterials,due to their good electrical conductivity and biocompatibility,have been widely used in many electrochemical fields such as electrochemical sensors,biofuel cells,etc.With the popularization of advanced nanotechnology and methods,carbon materials with various nanostructures,especially carbon nanomaterials prepared from biomass as precursors,have become research hotspots in the current concept of sustainable development due to their environmental friendliness,high availability,and low cost.In this paper,environmentally friendly biomass-based carbon nanomaterials were synthesized and further used as the modifier of the electrode to prepare ethanol electrochemical biosensors and ethanol BFCs based on alcohol oxidase?AOD?.The performance of the sensors and BFCs was studied.The main points of this dissertation are addressed as follows:?1?we synthesized dioscorea-derived carbon nanoaerogels?DCAs?which is nitrogen doped and has three-dimensional?3D?coral-like hierarchical micro-mesoporous carbons networks.The DCAs was used as the modifier of the screen printing electrode?SPE?and AOD was used as the catalyst.Tetrathiafulvalene?TTF?was employed as the redox mediator.The biological anode CS/AOD-TTF/DCAs/SPE was obtained after dropping the the chitosan?CS?solution on the electrode surface.On the biocathode,the bilirubin oxidase?BOD?was immobilized on the surface of SPE modified by DCAs to obtain BOD/DCAs/SPE for direct electron transfer.Based on this,a membraneless ethanol/O₂ BFC was constructed.In a buffer solution containing 5 mM ethanol at room temperature,the BFC exhibited an open circuit voltage?OCV?of 0.49 V and a maximum power density of 1.8 ?W/cm²,realizing electricity generation in different alcohol-containing beverages.?2?We constructed an ethanol electrochemical biosensor?AOD/DCAs/SPE?based on AOD using DCAs as the modifier of the electrode.The determination of ethanol is based on the consumption of the dissolved oxygen due to the enzymatic reaction.Compared with the performance of the biosensor using carbon nanotubes?CNTs?as electrode material,our biosensor showed more excellent performance including two wider well-defined linear ranges of 0.1-1 mM?R²=0.997?and 1-3.5 mM?R²=0.999??sensitivities of 1.072 and 0.591 ?A/mM cm²?and a lower detection limit?LOD?of 52.7 ?M.More importantly,our biosensor can be used to detect the ethanol level in real samples like commercial beverages and saliva and is capable in monitoring the ethanol level change in human saliva after alcohol consumption.