Control of monomeric Vo's versus Vo clusters in ZrO2-x for solar-light H2 production from H2O at high-yield (millimoles gr-1 h-1)

Yiannis Deligiannakis; Asterios Mantzanis; Areti Zindrou; Szymon Smykala; Maria Solakidou

doi:10.1038/s41598-022-19382-3

Control of monomeric Vo's versus Vo clusters in ZrO_2-x for solar-light H₂ production from H₂O at high-yield (millimoles gr^-1 h^-1)

Sci Rep. 2022 Sep 7;12(1):15132. doi: 10.1038/s41598-022-19382-3.

Authors

Yiannis Deligiannakis^{1

2}, Asterios Mantzanis³, Areti Zindrou³, Szymon Smykala⁴, Maria Solakidou^{3

5}

Affiliations

¹ Laboratory of Physical Chemistry of Materials and Environment, Department of Physics, University of Ioannina, Ioannina, Greece. ideligia@uoi.gr.
² Institute of Environment and Sustainable Development, University Research Center of Ioannina, 45110, Ioannina, Greece. ideligia@uoi.gr.
³ Laboratory of Physical Chemistry of Materials and Environment, Department of Physics, University of Ioannina, Ioannina, Greece.
⁴ Institute of Engineering Materials and Biomaterials, Silesian University of Technology, 18a Konarskiego St, 44-100, Gliwice, Poland.
⁵ Laboratory of Biomimetic Catalysis and Hybrid Materials, Department of Chemistry, University of Ioannina, 45110, Ioannina, Greece.

Abstract

Pristine zirconia, ZrO₂, possesses high premise as photocatalyst due to its conduction band energy edge. However, its high energy-gap is prohibitive for photoactivation by solar-light. Currently, it is unclear how solar-active zirconia can be designed to meet the requirements for high photocatalytic performance. Moreover, transferring this design to an industrial-scale process is a forward-looking route. Herein, we have developed a novel Flame Spray Pyrolysis process for generating solar-light active nano-ZrO_2-x via engineering of lattice vacancies, Vo. Using solar photons, our optimal nano-ZrO_2-x can achieve milestone H₂-production yield, > 2400 μmolg^-1 h^-1 (closest thus, so far, to high photocatalytic water splitting performance benchmarks). Visible light can be also exploited by nano-ZrO_2-x at a high yield via a two-photon process. Control of monomeric Vo versus clusters of Vo's is the key parameter toward Highly-Performing-Photocatalytic ZrO_2-x. Thus, the reusable and sustainable ZrO_2-x catalyst achieves so far unattainable solar activated photocatalysis, under large scale production.

Abstract

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