The Effect of Green Laser Irradiation on Photoelectrolysis

Abstract

Electrolysis uses a voltage to drive a reaction that yields hydrogen from the water contained in an Epsom salt solution. Advocates of the "hydrogen economy" have discussed hydrogen production as a potential medium of energy storage- electrical power would be produced by renewable sources and subsequently used to generate hydrogen through electrolysis. The resulting hydrogen gas would be chemically stable and able to be stored and distributed, thus overcoming the storage issues that currently afflict renewable wind and solar energy sources. The produced hydrogen gas can then be used to power fuel cells and efficiently convert the energy back to electrical power. This paper explores potential optimizations of photoelectrolysis, the process of performing electrolysis with the addition of a laser irradiating the cathode. Concentration of Epsom salt is a key variable that was tested. Experiments have shown that a higher concentration of Epsom salt will produce hydrogen at a faster rate. However, further optimization of this process is desired. It has been suggested that the addition of a green laser aimed at the cathode will accelerate the reaction by stretching the bond between the hydrogen and oxygen molecules. This research indicates that the green laser has a significant effect within a certain concentration range. At the highest performing concentration the addition of the laser resulted in an approximate doubling of hydrogen production rate, an increase that justifies the additional power requirement of the laser.