Abstract
This paper proposes to manipulate the thickness of the electro-double-layer (EDL) inside the anodic aluminum oxide (AAO) nanochannels as an ionic diode membrane to select uni-ions as through electrical static charges. By applying enough bias on membrane, EDL can overlap and block counter ion outside the channel in 10nm holes, which is 2~10 times larger than the membrane of Pressure-Retarded Osmosis or Reverse Electrodialysis. The resistance of EDL overlapped is 3.2~7.1 lower than non-overlapped. Besides, by applying negative bias on membrane can induce negative charges on HfO2 surface, which is opposite to the AAO surface in the electrolyte to form a heterojunction interface. Based on the reference [11], this heterojunction interface between two different charge layers can suppresses the ions concentration polarization (ICP) effect and enhances the rectification ratio. The resistance of the membrane with this heterojunction interface is 9.27 lowers than the membrane without it. Finally, proving by experiment, this membrane can be used in salinity power generation, which is considering as a great potential, renewable energy.