One dimensional efficient photocatalyst based on plasmonic grating

Abstract We can summarize the benefits of the water photocatalysis by two words: clean energy and purification of pollutants, and its problems as the large energy gap and electron-hole recombination. Scientists are still looking for a semiconductor whose energy gap lies in the visible region, with electron-hole pairs of longer life time. One of the proposed solutions in this field is combining the available semiconductors (such as TiO2) with a metal of plasmonic properties. The existing of the plasmonic metal will ensure that the visible portion of the solar region will involve in the photocatalysis action. It will be absorbed by the plasmonic metal, be transformed into a local energy that leads to excitation processes in the semiconductor. Also, the existing of the metal will guarantee a longer life time for the electron-gap pairs generated in the semiconductor, as the metal acts as a sink for the electrons generated in the semiconductor. In this paper, we created a unique photocatalyst based on one dimensional grating coated by gold thin film and covered by TiO2 cap layer. By examining the sample with visible radiation, we obtained a rate of sabotage of 25 percent within three hours.