Solar energy is the most abundant and sustainable energy on earth, but it is also diffuse. Therefore, to utilize this energy it should be converted to storable energy, such as chemical energy in solar fuels.
As a promising means of solar energy conversion, photovoltaic (PV) cell-based electrolysis has drawn considerable attention for its effective solar fuel generation, especially the generation of hydrogen by solar water-splitting. Numerous studies have achieved remarkable accomplishments in enhancing the solar-to-hydrogen (STH) conversion efficiency by employing tandem or interconnected PV cells as photodriven devices with the help of optimized catalysts. In addition, optimal design of the PV-electrolysis module is required for effective use and commercialization of these systems.
Inspired by this critical need, various efforts have aimed at fostering convenient and practical uses of PV-electrolysis to make this technology ubiquitous, manageable, and efficient. However, for versatile usage of the system, there are still many considerations that need to be resolved in the application of artificial leaves in natural environments.
In Advanced Materials, researchers from Pohang University of Science and Technology and the Korea Institute of Ceramic Engineering and Technology, Korea, have reported the design and function of a monolithic photoelectrolysis system—a so-called artificial leaf—for use in various environments.
A floatable and planar compact artificial leaf was newly developed with a unique configuration, which makes the module applicable in various environmental conditions. An adjustable free-space between the electrodes substrate and the PV cells in series enables the artificial leaf to float on the surface of water, fully utilizing the incident solar light in turbid or deep water conditions without absorption loss. The leaf’s floatability provides another benefit; that is, easy retrieval of the module after use, which saves resources and prevents pollution. Additionally, the single-face electrodes allow the device to operate even in water-scarce conditions, as long as the catalyst surface is wetted.
These characteristics endow this artificial leaf with versatility and a high adaptability to natural environments, widening the applicability of the device for ubiquitous generation of energy in the future.