Assembly of quinone-based renewable biobattery using redox molecules from Lawsonia inermis

The current study tested the hypothesis whether common plant extracts could be used as redox molecules in biobattery. Natural quinone molecules were extracted from Lawsonia inermis (henna) via sequential extraction using hexane, ethyl acetate, methanol and 80% methanol in water, followed by purification using column chromatography to examine their potential function as redox molecules in biobattery. A combination of UV–visible spectroscopy and gas chromatography–mass spectrometry (GC–MS) analysis confirmed the presence of quinones in the extracted fractions. UV analysis showed maximum absorbance at 295 nm and 450 nm which correspond to 4- t -butyl-1,2-benzoquinone and duroquinone. In addition, GC–MS analysis of the henna extract confirmed the presence of tocopherol (vitamin E) as a potential redox molecule. We determined the impact of the type of electrolyte, electrode, salt bridge and volume of extract on the overall efficiency of biobattery. Among the different cell combinations tested, the optimum battery with a maximum voltage of 0.97 V was achieved using a carbon||quinone cathodic half-cell, copper||sulphuric acid anodic half-cell and a KCl (1.0 M) salt bridge. Our experiments demonstrate that natural redox molecules from common African plants, including L. inermis extracts, can serve as source of electrical energy and alternative materials for the renewable battery.