A hybrid biofuel cell, a zinc-air cell employing laccase as the oxygen reduction catalyst is investigated. A simple cell design is employed; a membraneless single chamber and a freely suspended laccase in the buffer electrolyte. The cell is characterised based on its open-circuit voltage, power density profile and galvanostatic discharge at 0.5 mA. The activity of laccase as an oxidoreductase is substantiated from the cell discharge profiles. The use of air electrode in the cell design enhanced the energy output by 14%. The zinc-air biofuel cell registered an open-circuit voltage of 1.2 V and is capable to deliver a maximum power density of 1.1 mWcm-2 at 0.4 V. Despite its simple design features, the power output is comparable to that of biocatalytic cell utilising a much more complex system design.
Various production methods have been developed for graphene production, but each of them falls short in either the economic or quality aspect. In this paper, we present the flame deposition method, a modified chemical vapor deposition (CVD) that uses an open-flame. In this method, resulting carbon deposits were found to be graphitic in nature, thereby suggesting multilayer graphene growth in a very short reaction time of 5 min. Furthermore, the deposits were transferred onto a cyanoacrylate plastic substrate and its sheet resistance was measured to be 81 ohm/square. The results showed that open-flame deposition exhibits high potential for low-cost, low-energy and high-quality production of graphene.