Study On Salinity Difference Energy Conversion Of The Graphene Oxide Membrane

Since the industrial revolution,the consumption of fossil energy has been increasing,resulting in more and more serious problems of energy shortage and environmental pollution,and the development and utilization of clean energy has become the consensus of all countries in the world.Salinity difference energy,a blue energy widely existing between sea water and river water,is also a highly competitive but largely underutilized clean energy.In this paper,the salinity difference energy conversion performance of graphene oxide composite membranes with different structures was studied by experimental and numerical simulation methods.In this paper,graphene oxide was successfully synthesized by improved Hummer method.Infrared spectrum analysis showed that the prepared graphene oxide had three functional groups:hydroxyl group,carboxyl group and epoxy group.Graphene oxide membrane was prepared by deposition of graphene oxide nanosheet on mixed cellulose ester film by vacuum filtration method,its space of the layers was 0.86 nm,the structure was uniform and the performance was stable.Taking graphene oxide as the research object,the salinity difference energy power generation effect of graphene oxide membranes with two structures of horizontal diffusion and vertical diffusion was compared.The experimental results show that the horizontal diffusion channel of graphene oxide membrane can realize high flux and selective transport of ions.In NaCl solution system with a concentration difference of 500|10 mM(sea water-river water),the maximum electric power density of conversion 5.29 W/m2.By changing the pH of the system and choosing different electrolyte solutions,the energy conversion efficiency of the system can be effectively improved.The vertical and horizontal diffusion models of different lamellar configurations are established by finite element numerical simulation,the transport behavior of electrolyte ions in different models of nanopore and the influence of the pore length of nanopore on the concentration difference power generation were discussed by solved the two-dimensional Poisson and Nernst-Planck equations.The numerical simulation results showed that the lower flow resistance the relatively larger diffusion current in the transverse diffusion model was mainly attributed to the high carrier concentration in the nanopore and the high pore density in its structure;when the length of the nanopore is short,the concentration difference power of the nanopore decreases with the decrease of the pore length due to the decrease of the ion selectivity and the effective concentration difference of the nanopore.In this paper,a new idea for the design of ion-selective membrane for high-performance concentration generation is opened up by the proposed energy conversion system of graphene oxide membrane interlayer transport of salinity difference energy conversion.Different models of nanopore concentration difference power generation are simulated,and the mechanism of nanopore concentration difference generation is analyzed and discussed in depth,theoretical guidance is provided for the actual.improvement of power generation.