Synthesis Of Biomimetic Nano-pilus And Research On Promoting Microbial Mutual Methane Production

With the progress and development of modern society,the excessive exploitation and utilization of energy has caused a series of severe environmental problems.In order to improve the energy structure based on fossil energy and promote sustainable development of society,the development of biomass energy represented by methane is an effective way to solve energy problems.Anaerobic digestion is one of the most promising energy conversion technology to produce biofuel?mainly methane?from organic solid wastes.However,low efficiency and long retention times,which usually occur in anaerobic digestion,prevent its development.At present,it is found that the addition of highly conductive nanomaterials such as nanographene,iron oxide,biochar and so on in the anaerobic digestion system can effectively shorten the reaction lag period of the methanogenesis stage and improve the methanogenic efficiency.However,the above materials are much smaller in scale than the bacteria,it is difficult to bridge adjacent bacteria,and the electron transfer efficiency in the solution is low.And they also has the disadvantages of cytotoxicity and poor biocompatibility,which all limit the application of nanomaterials in anaerobic digestion.To counter the problems above,,a bio-modified ultrathin gold nanowire based on the bionic design of the natural structure of the bacteria was synthesized to construct a direct electron transport pathway to promote the methanogenic efficiency of bacteria in anaerobic digestion.In this experiment,ultrathin gold nanowires were successfully prepared by using oleylamine as a soft template to reduce HAu Cl₄·3H₂O.The micro-nano structure of this material is consistent with the pili.The average diameter and length of the Au-NWs were 1.8 nm and several micrometers,respectively,and thus the large aspect ratio of the wires provides them with an extraordinary flexibility and can be bent freely to effectively connect adjacent cells.Through self-assembly,the gold nanowires form a honeycomb macroporous structure with high conductivity creat on the surface of the silicon substrate.Further modifying the nucleic acid molecule4,6-diamino-2-mercaptopyrimidine?DAPT?on the surface of the gold nanowire of the assembled structure,which has improved the biocompatibility with bacteria and realized the efficient enrichment of methanogens on the honeycomb gold wire substrate.This material greatly enhances the gas production efficiency of methanogens in anaerobic digestion and increases methane production by 3.2 times.In addition,the preparation of the Ag nanowire array for sulfide removal in gasoline was designed and prepared.In this experiment,silver nanowires with uniform morphology and good crystallinity were rapidly synthesized by liquid phase polyol method with silver chloride as seed crystal.Ag nanowire arrays were produced by the self-assembly of Ag-NWs on a liquid-air interphase.This highly ordered,macroscopic arrays can increase the plasmon resonance and electron cloud density on the surface of the nanowires,promote its combination with sulfide,and achieve the initial removal of sulfide in gasoline at room temperature.