Enhanced photoelectrochemical water splitting behaviour of tuned band gap CdSe QDs sensitized LaB6

Abstract

We report the fabrication of tuned band gap quantum dots sensitized LaB6 hybrid nanostructures and their application as a photoanode for photoelectrochemical water splitting. The lanthanum hexaboride (LaB6) obtained by molten salt electrolysis method is sensitized with different sized CdSe quantum dots, which form a multiple-level hierarchical heterostructure and such design enhance the light absorption and charge carrier separation, which in turn showed higher photocurrent density compared to that of pristine LaB6. When LaB6 is sensitized with CdSe quantum dots of different band gaps, which have the absorption in the green and red (530 and 605 nm) regions in visible light, developed a ten times higher photocurrent density (11.0 mA cm-2) compared to that of pristine LaB6 (0.5 mA cm-2 at 0.75 V vs. Ag/AgCl) in 1 M Na2S electrolyte under illumination. These results prove that the tuned band gap quantum dots sensitized LaB6 heterostructures are an ideal candidate for a photoanode in solar water splitting applications. Copyright 2017 American Scientific Publishers All rights reserved.