Towards sustainable TiO2 photoelectrodes based on cellulose nanocrystals as a processing adjuvant

Martínez-Barón, C. ; Calvo, V. ; Hernández-Ferrer, J. ; Villacampa, B. (Universidad de Zaragoza) ; Ansón-Casaos, A. ; González-Domínguez, J. M. ; Maser, W. K. ; Benito, A. M.

Resumen: Photoelectrodes of TiO2 in the form of films are commonly fabricated using screen printing techniques, employing viscous commercial TiO2 pastes. However, these pastes comprise environmentally unfriendly, multicomponent formulations designed to manufacture the photoactive TiO2 nanoparticles. To strive for sustainable processing and pave the way for the use of liquid-phase film processing technologies, the inherent limited water dispersibility of TiO2 nanoparticles must be overcome. In this study, we show that cellulose nanocrystals, produced via an environmentally benign one-pot hydrolysis process, enable the preparation of stable TiO2 water dispersions. The remarkable stability of these dispersions, evidenced by their outstanding ξ-potential values of −34 mV, facilitates the fabrication of macroporous TiO2 photoactive films throughout spray coating. Employed as photoanodes in a photoelectrochemical cell, our TiO2 photoanodes are compared with conventional TiO2 electrodes obtained from commercial pastes under water splitting conditions. Interestingly, our photoanodes reveal a remarkable three-fold enhancement of the photocurrent performance (132 vs. 46 μA cm−2) and a four-fold increase in the on–off response rate (4 vs. 1 s). These findings underscore the valuable role of cellulose nanocrystals as a green processing asset for achieving TiO2 water dispersions. Moreover, they serve as sacrificial adjuvants for preparing highly macroporous and functional film photoelectrodes, representing a significant step forward in the pursuit of sustainable and efficient materials processing.

Idioma: Inglés

DOI: 10.1039/d4su00160e

Año: 2024

Publicado en: RSC Sustainability 2, 7 (2024), 2015-2025
ISSN: 2753-8125

Financiación: info:eu-repo/grantAgreement/ES/DGA/E47-23R
Financiación: info:eu-repo/grantAgreement/ES/DGA/T03-23R
Financiación: info:eu-repo/grantAgreement/ES/MICINN PID2020-120439RA-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2022-139671OB-I00

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)