Speaker
Description
One of the greatest challenges of the 21st century is to reduce greenhouse gas emissions, while keeping the standard of living, by using more clean and renewable energy sources. Sunlight is by far the most abundant renewable source of energy, exceeding the potential of all other energy sources, and capable of supplying the present and projected world’s energy demands. Photoelectrochemical (PEC) cells offer an excellent method of producing both electrical (dye-sensitized solar cells - DSCs) or chemical energy (fuel - H2 production by water splitting) [1]. H2 generation via PEC solar water splitting is a promising approach since it combines the solar harvesting, conversion, and storage functionalities all-in-one, which is favorable in terms of packaging and overall system costs. Materials based on n-type metal oxides such TiO2, α-Fe2O3, or WO3 have gained relevance for such applications due to their low cost, easy preparation, synthesis, and high stability in aqueous media. Nanostructuring has emerged as one of the best tools to enhance the photoelectrodes' efficiency response. Different synthesis methods for preparing nanostructured photoelectrodes with different geometries (e.g. nanoparticles, nanoplatelets, nanopores, nanowires, nanotubes, etc.) have been widely explored to obtain an enhanced efficiency in the photoresponse, specifically by physical, electrochemical, and chemical routes. More recently, a great interest in nanotubes and nanowires geometry has emerged for applications in PECs. We propose to implement the most abundant/low cost and chemically stable, semiconductors oxide materials (e.g. TiO2, α-Fe2O3, WO3) using highly scalable (low cost) synthesis methods: hydrothermal, chemical, and electrochemical anodization processes. We obtained nanostructured photoelectrodes, nanoplatelets, nanowires, or hexagonally-ordered nanotubes arrays of semiconducting oxides for the PEC solar cells applications [2-5]. Detailed characterization and optimization of such nanostructures were made with detail and thoroughness to optimize the photoresponse.
References
[1] Grätzel, M., Nature, 414(6861), 338-344 (2001).
[2] A. Apolinário, et al. Journal of Materials Chemistry A, 2, 9067-9078 (2014),.
[3] Apolinário et al., J. Phys. Chem. Letters, 6 (5), 845-851 (2015).
[4] A.Apolinário, et al. ACS Applied Energy Materials 2 (2), 1040-1050 (2019).
[5] P.Quitério, A.Apolinário, et al. J. Phys. Chem. C 124, 24, 12897–12911(2020).
[6] ] A.Apolinário, et al. Nanomaterials 10 (2), 382 (2020).
