The Performance And New Mechanism Of Generator Derived From ZSM-5 Driven By Natural Solution Evaporation

Natural solution evaporation generators（NSEG）have been proposed on the basis of the"water-volt effect".NSEG can transfer the evaporation energy from solution into electrical energy in the environment,which provides a new way for exploring green,environmental protection and new energy.Generally speaking,the electrical power generation materials have some features such as hydrophilic,charged surface,nanochannels.And the mechanism of NSEG is attributed to the streaming potential mechanism.However,the understanding of structural properties of materials are still at the macro level,the energy change during the process of natural solution evaporation has paid little attention.In addition,solid-liquid interaction includes two processes:surface evaporation and flow in nanochannels.Whether the charge transfer on the surface and ion flow in the nanochannels are manifested as only streaming potential remains a challenge.According to the characteristics of the power generation materials,ZSM-5 was selected as the power generation material in this study.Its structure regulation was adjusted by adding different amounts of structural guide agent.The change of the energy caused by the material structure regulation in the water contact process was studied,and the energy efficiency relationship between the power generation induced by solution evaporation and the energy change was established.Moreover,a new mechanism of solution evaporation-induced power generation was proposed by means of probe method,salt solution concentration regulation method,organic solvents regulation and side evaporation area regulation.Specific research contents are as follows:1.In order to study the energy change between the electrical power materials and water in the process of natural solution evaporation,the structure of ZSM-5 was regulated and the influence of energy change was studied.The structure of ZSM-5including morphology,pore size,Si/Al ratio were regulated by tailoring the content of structure guide agent TPAOH.Si O₂ zeolite and series ZSM-5 with different Si/Al ratios were synthesized with TPAOH adding amounts of 0,1.50,3.55 and 7.00 m L with fixed factors.All the materials were characterized and assembled into NSEG to study the output electrical performance.The results show that ZSM-5/T3.55 has negative surface charge,uniform particle size,abundant pore size distribution,and minimum Si/Al ratio of 42.0 in all samples.Compared with other power generation materials,ZSM-5/T3.55based NSEG has the largest open-circuit voltage(V_oc)of 1.35 V and short circuit current(I_sc)of 223 n A when it evaporates in DI water.The energy change in the contact process between the material and water was analyzed by DSC test and DFT calculation.The enthalpy of evaporation of DI water is decreased from 2424 J/g to 1441 J/g after the addition of ZSM-5/T3.55 by thermodynamic analysis,which reduces the heat energy for DI water to evaporate.From the kinetic analysis,the binding energy of Si O₂ zeolite with water is-0.0003e^-calculated by DFT model.However,compared with Si O₂ zeolite,the presence of Al in ZSM-5/T3.55 enhances the binding force with water.Therefore,the binding energy of ZSM-5/T3.55 reaches-0.0005e^-,which promotes the easy migration of water molecules.Hence,ZSM-5/T3.55 not only reduces the enthalpy of water evaporation in the process of natural solution evaporation thermodynamically,but also promotes the migration of water molecules dynamically.By this way,the NSEG efficiently realize the conversion of evaporative energy to electric energy.In addition,the maximum output power of the ZSM-5/T3.55 based NSEG is about 0.301μW when the thickness of ZSM-5 film is 13μm height is and 2.5 cm.2.In view of the mechanism of NSEG,the widely accepted one is only streaming potential.However,we propose a“dual mechanism”in the process of natural solution evaporation generation.On the one hand,the evaporation potential occurs at the interface between electrical power generation materials and solution by transferring charge.On the other hand,the streaming potential is formed between the inside nanochannel of material and solution by the dynamic effect.Therefore,we propose a new mechanism of NSEG which is dominated by evaporation potential and synergistic with streaming potential.Several methods have been used taking ZSM-5/T3.55 based NSEG as the research object.First,the V_oc at different evaporation heights in DI water and different concentrations of Na Cl solutions was measured by probe method.The coexistence of evaporation potential and streaming potential is first discovered.Second,the solution evaporation enthalpy and vapor pressure regulations were obtained by salt solution concentration regulation method.It is found that the higher concentration of Na Cl solution shows a higher evaporation enthalpy but a lower vapor pressure,resulting in the lower evaporation potential and streaming potential.Then the output electrical performance of NSEG is reduced.Third,a series of organic solvents were studied to verify the existence of evaporation potential and the driving force of NSEG by the solution regulation method.Finally,the side evaporation regulation method was used in the process of solution evaporation.It is found that the larger evaporation area is conductive to the evaporation and flow of water molecules.Therefore,the evaporation potential and streaming potential are enhanced simultaneously which results in a higher V_oc.Based on the above analysis,this study proposes a“dual mechanism”of synergistic evaporation potential and streaming potential to explain the phenomenon of natural solution evaporation generation.