The electrochemical study of fast catalytic reactions is limited by mass transport using the conventional electrochemical cell with a rotating disk electrode (RDE).
Solar hydrogen generation via water
splitting using a monolithic
photoelectrochemical cell, also called artificial leaf, could be a
powerful technology to accelerate the transition from fossil to sustainable
energy sources. Identification of scalable methods for the fabrication
of monolithic devices and gaining insights into their operating mode
to identify solutions to improve performance and stability represent
great challenges. Herein, we report on the one-step fabrication of
a CoWO|ITO|3jn-a-Si|Steel|CoWS monolithic device via the simple photoinduced
deposition of CoWO and CoWS as oxygen evolution reaction (OER) and
hydrogen evolution reaction (HER) catalyst layers, respectively, onto
an illuminated ITO|3jn-a-Si|Steel solar cell using a single-deposition
bath containing the [Co(WS4)2]2– complex. In a pH 7 phosphate buffer solution, the best device achieved
a solar-to-hydrogen conversion yield of 1.9%. Evolution of the catalyst
layers and that of the 3jn-a-Si light-harvesting core during the operation
of the monolithic device are examined by conventional tools such as
scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy
(EDX), and inductively coupled plasma optical emission spectroscopy
(ICP-OES) together with a bipotentiostat measurement. We demonstrate
that the device performance degrades due to the partial dissolution
of the catalyst. Still, this degradation is healable by simply adding
[Co(WS4)2]2– to the operating
solution. However, modifications on the protecting indium-doped tin
oxide (ITO) layer are shown to initiate irreversible degradation of
the 3jn-a-Si light-harvesting core, resulting in a 10-fold decrease
of the performances of the monolithic device.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.