Energy harvesting properties of chitosan film in harvesting water vapour into electrical energy

摘要

A water vapor cell (WVC) made of chitosan-based film has been successfully generated electrical energy when directly interacted with water vapor. The chitosan concentration in film was varied from 0 to 4.5%. WVC was characterized using a climate chamber oven to determine the energy harvesting properties when exposed to water vapour which represented as relative humidity (30-90% RH). No electrical energy was generated by 0% chitosan film. However, the other concentration generated electrical energy started to increase and reaching almost a steady state after 13-11 h exposure to > 70% RH. The highest electrical energy was 120.13 mu W obtained by 4% chitosan film and maintained continuously under 90% RH exposure. This electrical energy generation was due to the chemical interaction of hydrogen bonding that occurs between water vapor molecules and amine groups (NH2) of chitosan film as proven by FTIR analysis. Furthermore, chitosan film morphology was also contributing to the energy harvesting ability as proven by AFM and FESEM analyses where film concentration <= 4.0% have a smooth surface which favored the electrical energy generation.