WITHDRAWN: Power Generation by Water Transpiration from Microporous Alumina

Abstract

Hydropower generation has been the most developed sustainable energy source that is based on the electromagnetic transduction of the gravitational potential energy but is only realized through elaborate construction of water dam and not yet suitable for small-scale energy harvesters. Here, we report that wetting and evaporation of water from a small block of porous alumina can generate electrical current in the direction of water transpiration. This induced current in microporous alumina is associated with the mass transport of water accompanying the accumulated charge near the negatively charged surface of the alumina pore. Without any pre-treatment or additives, once water evaporation commences, a 3×3 cm2 piece of alumina generates an open-circuit voltage of up to 0.27 V. Possible influence on power generation of the water-insulator interface and naturally available protons in water are discussed with respect to experimental results. Total output of this novel microporous ceramic electric generator can be scaled up and could be used for stand-alone energy harvesters or power generators in self-powered off-grid agricultural/ industrial sensors.