Light-driven oxygen evolution from water oxidation: TiO2 engineering in the performance of the immobilised photocatalysts

• Type: Other Publications
• Date: 2021

Authors

Sampaio, M.J. (Author) FEUP; Yu, Z (Author) Other; Lopes, JC (Author) Other; Tavares, PB (Author) Other; Claudia G Silva (Author) FEUP; Liu, L (Author) Other; Joaquim Luís Faria (Author) FEUP

Associated Projects

LA LSRE-LCM - Financiamento Plurianual 2020-2023 para a Unidade LA LSRE-LCM Laboratório de Processos de Separação e Reacção - Laboratório de Catálise e Materiais

Other information

Authenticus ID: P-00Z-2A5

DOI: 10.21203/rs.3.rs-799280/v1

Abstract (EN): <jats:title>Abstract</jats:title> <jats:p>Calcination treatments in the range of 500¿900 ºC of TiO<jats:sub>2</jats:sub> synthesised by the sol-gel resulted in materials with variable physicochemical (<jats:italic>i.e.</jats:italic>, optical, specific surface area, crystallite size and crystalline phase) and morphological properties. The photocatalytic performance of the prepared materials was evaluated in the oxygen evolution reaction (OER) following UV-LED irradiation of aqueous solutions containing iron ions as sacrificial electron acceptors. The highest activity for water oxidation was obtained with the photocatalyst thermally treated at 700 ºC (TiO<jats:sub>2</jats:sub>-700). Photocatalysts with larger anatase to rutile ratio of the crystalline phases and higher surface density of oxygen vacancies (defects) displayed the best performance in OER. The oxygen defects at the photocatalyst surface have proven to be responsible for the enhanced photoactivity, acting as important active adsorption sites for water oxidation. Seeking technological application, water oxidation was accomplished by immobilising the photocatalyst with the highest OER rate measured under the established batch conditions (TiO<jats:sub>2</jats:sub>-700). Experiments operating under continuous mode revealed a remarkable efficiency for oxygen production, exceeding 12% of the apparent quantum efficiency (AQE) at 385 nm (UV-LED system) compared to the batch operation mode.</jats:p>

Language: English

Type (Professor's evaluation): Scientific