Unveiling Morphology-Structure Interplay on Hydrothermal WO₃ Nanoplatelets for Photoelectrochemical Solar Water Splitting

• Type: Another Publication in an International Scientific Journal
• Date: 2024

Authors

Sofia Gonçalves (Author) Other; Paula Quitério (Author) Other; João Freitas (Author) Other; Dzmitry Ivanou (Author) Other; Lopes, T. (Author) FEUP; Adélio Mendes (Author) FEUP; João P. Araújo (Author) Other; Célia T. Sousa (Author) Other; Arlete Apolinário (Author) Other

Journal

Title: ACS Applied Materials & Interfaces

Vol. 16

ISSN: 1944-8244

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 1 Citation

Other information

Authenticus ID: P-017-FZQ

DOI: 10.1021/acsami.4c11729

Abstract (EN): Photoelectrochemical (PEC) water splitting offers a sustainable route for hydrogen production, leveraging noncritical semiconductor materials. This study introduces a seed layer-free hydrothermal synthesis approach for semiconductor photoanodes based on tungsten trioxide (WO3) nanoplatelets. Aiming to boost the efficiency of photoelectrochemical water splitting through optimization of the synthesis parameters of bare WO3, focusing on temperature, time, and layer thickness, we systematically explored their effects on the morphological, structural, and optical characteristics of WO3 photoanodes. Combining a low-temperature regime (90 degrees C for 12 h) with a multilayer strategy (up to six-layers) resulted in significant improvements in photocurrent. Particularly, the five-layer sample exhibited a remarkable increase of over 70% compared to the single-layer photoanode. Morphological aspects, particularly the fractal dimension of nanoplatelets and the emergence of the (220) crystalline orientation, usually neglected, were found to play pivotal roles in modulating the PEC response. Rietveld refinement of X-ray diffraction patterns further underscored the importance of crystallographic facets, volume unit cell expansion, and microstrain in influencing photocurrent outcomes. Furthermore, we adapted the Mott-Schottky equation to incorporate the fractal dimension reflecting the nanostructures' nature, usually set to a planar interface. Our findings highlight the interchange between nanoplatelet morphology and structural parameters in determining the PEC efficiency of WO3 photoanodes.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 21