Researchers are combining two promising photocatalysts to achieve greater efficiency in converting sunlight to hydrogen and longer life in a water-splitting cell.
We must abandon fossil fuels if we are to avoid a climate catastrophe. Industry and research have emphasized hydrogen as a clean alternative. Hydrogen is virtually limitless and only produces water vapor when utilized to create energy. To develop a fully eco-friendly hydrogen society, we must first be able to cleanly mass-produce hydrogen.
One method is “artificial photosynthesis,” in which materials, called “photocatalysts,” harness sun energy to divide water into oxygen and hydrogen. However, current photocatalysts are not cost-effective or scalable for solar water splitting. To get there, two major issues must be addressed: the inefficiency of STH conversion and the fragility of photoelectrochemical water splitting cells.
Professor Masashi Kato and his team at the Nagoya Institute of Technology in Japan worked hard to improve photocatalysis by investigating new materials and their combinations, as well as the underlying physicochemical mechanisms. Dr. Kato and his team have now achieved this by combining titanium oxide (TiO2) and p-type cubic SiC (3C-SiC), two promising photocatalyst materials, into a tandem structure that is a highly robust and effective water-splitting cell.
The tandem structure studied by the team has semi-transparent TiO2 as the photoanode and 3C-SiC as the photocathode. This is because the tandem construction allows more light to excite charge carriers and generate currents, increasing the conversion efficiency of the water gap cell.
The scientists then tested the effects of external voltage and pH on photocurrents generated in the cell before testing water splitting at various light intensities. They counted the oxygen and hydrogen produced. Dr. Kato says the results were encouraging “With the bias, the maximum photon-to-current efficiency was 0.74 percent. Our water splitting system is among the best currently available, with a lifespan of around 100 days.” The results of this investigation also revealed several plausible causes behind the proposed tandem structure’s performance.
Before photoelectrochemical water splitting devices can be extensively employed, more study is required. Still, this study is a step in the right direction. “Our contributions will help to accelerate the development of artificial photosynthesis, which will produce energy directly from sunlight. Our discoveries can thus aid in the creation of sustainable societies “Dr. Kato’s vision
