Study On Fabrication Of Enzymatic Biofuel Cells And Bio-photoelectrochemical Systems

With the rapid development of the global economy,the problems of energy shortage and environmental pollution caused by the consumption of traditional fossil fuels are intensifying.In response to these severe challenges,it is of great significance to enhance the exploitation of renewable energy to ensure energy security and maintain sustainable economic development.Enzymatic biofuel cells(EBFCs)are a type of green electrochemical devices that convert biomass chemical energy into electricity.With its environment-friendly and pollution-free characteristics,EBFC is expected to become one of the new approach to exploit renewable energy sources.In this thesis,we carried out a serious of research works on the exploitation and utilization of biomass chemical energy and solar energy by fabricating the EBFCs and bio-photoelectrochemical systems(BPECS).The main points are outlined as following:1.From the perspective of the design and synthesis of nanomaterials,we developed the three-dimensional nanocomposites of reduced graphene oxide/Au NPs/nitrogen-doped carbon nanotubes(3D RGO/Au NPs/N-CNTs)and expanded its application as self-supporting electrode in EBFCs.Combining the techniques of electrochemical deposition and chemical vapor deposition,the RGO,Au NPs,and N-doped CNTs were seamlessly attached on the surface of nickel foam,which not only provided large specific surface area and stable bionic environment for enzymes immobilization,but also increased the reactive sites in electrocatalysis.As a result,the assembled glucose oxidase electrode based on 3D RGO/Au NPs/N-CNTs exhibited excellent bioelectrocatalytic performance and obtained 7.02 mA cm-2 at 0.3 V.2.From the perspective of bionic design,we carried out the research of nanozyme and expanded its application in EBFCs.Inspired by native structure of cytochrome c oxidase(CcO),CcO-like FeN5 single-atom nanozymes(FeN5 SAs)were developed.The remarkably high CcO-like activity(KM,4.2×10-5 M)and competitive ORR electrocatalytic performance(E1/2,0.67 V)of FeN5 SAs indicates that the cross-merging between single-atom nanomaterials and artificial enzymes can provide an rational entry point to guide the research of next-generation nanozymes.Coupling a glucose dehydrogenase(GDH)bioanode,the assembled FeN5 SAs-based glucose/O2 EBFC exhibited great performance in energy conversion.3.From the perspective of multi-energy utilization,the study and fabrication of enzymatic BPECS were carried out.Combining the research of water oxidation in photoelectrochemical system and oxygen reduction in bioelectrochemical system,a fuel-free BPEC(Anode:Ni:FeOOH/BiVO4;Cathode:Lac)was assembled to achieve simultaneous conversion of both solar energy and biomass chemical energy into high-quality clean electricity.Furthermore,in response to the intermittent problem of sunlight,arising from earth rotation,the energy storage module of polypyrrole(PPy)capacitor was introduced into fuel-free BPEC(Anode:TiO2;Cathode:BOD)to complete the storage and conversion of solar energy,which provides a feasible solution for tackling the discontinuous energy conversion caused by the intermittent nature of sunlight.