Fabrication of hemisphere nanostructure and application for photoelectrochemical catalyst via secondary sputtering lithography

Abstract

Due to greenhouse gas emission, problem of global warming is arising more seriously annually. Especially, use of fossil fuels which is one of the main reason for global warming is a crucial issue. For this reason, many alternative energy sources that can replace current fossil fuel is getting attention. One of the most promising next generation energy is hydrogen, and there has been many studies to efficiently produce hydrogen. Many catalysts have therefore been researched and one of the most appealing one is photoelectrochemical (PEC) catalyst. PEC catalyst works as semiconductor excites electrons by the absorbed light, and use these electrons in addition to the applied bias for catalytic reaction. Thus, it is important for the catalyst to absorb the fixed amount of light efficiently and use the excited electrons for the desired reaction without much loss. In the current work, we fabricated hemisphere nanostructure with copper oxide and efficiently absorbed light. Also, we increased surface area compared to the film structure in order to increase the catalytic reaction site. PEC test was conducted in order to confirm the effect of the nanostructure. By the hemisphere nanostructure, current density of the fabricated sample was higher compared to film sample, and we could infer that efficient catalytic reaction took place.