On the relevance of understanding and controlling the locations of dopants in hematite photoanodes for low-cost water splitting

Autor(es)

Souza, Jr., Joao B. ^[1] ; Souza, Flavio L. ^{[1, 2]} ; Vayssieres, Lionel ^[3] ; Varghese, Oomman K. ^[4]

Afiliação do(s) autor(es)

^[1] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-13083970 Campinas - Brazil

^[2] Fed Univ ABC UFABC, Ctr Ciencias Nat & Humanas CCNH, BR-09210580 Santo Andre, SP - Brazil

^[3] Xi An Jiao Tong Univ, Int Res Ctr Renewable Energy IRCRE, Sch Energy & Power Engn, State Key Lab Multiphase Flow Power Engn, Xian 710049 - Peoples R China

^[4] Univ Houston, Dept Phys, Nanomat & Devices Lab, Houston, TX 77204 - USA

• Tipo de documento: Artigo Científico
• Fonte: Applied Physics Letters; v. 119, n. 20 NOV 15 2021.
• Citações Web of Science: 0

Resumo

Successful large-scale implementation of solar fuel technologies relies on cost, performance, and reliability of materials, devices, and infrastructures. Earth-abundant, low-cost, easily recyclable, and environmentally benign light absorbers are desired for renewable fuel generation technologies, such as solar photoelectrochemical (PEC) water splitting. Hematite is considered an ideal material for PEC oxygen evolution reaction, which is a critical component in the overall water splitting process for hydrogen fuel generation. However, intrinsic and operational limitations have prevented hematite-based PEC devices from reaching their highest theoretical solar-to-hydrogen efficiency of 15%-17%. Literature clearly shows that no single approach can eliminate these limitations. An overall fundamental understanding of the effect of dopant addition as well as their physical locations and functions within the photoelectrode, in both as-synthesized form and under operating conditions, is of critical importance to unleash the tremendous potentials of hematite-based PEC systems. In this short perspective, the concept of effective doping (i.e., increase of charge carrier density) up to the limit of dopant segregation at the grain boundaries to lower the charge recombination is discussed. Based on relevant theoretical and experimental data from the literature on the effects of surface-to-bulk doping as well as dopant segregation at the grain boundaries on hematite photoelectrode performance, we discuss here the views on the necessity of understanding these processes and their individual and synergistic effects to unravel a simple yet powerful approach to design and develop highly efficient hematite photoanodes for clean hydrogen generation using water and sunlight. (AU)

• Processo FAPESP: 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte
• Beneficiário: Adalberto Fazzio
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/11986-5 - Geração e Armazenamento de Novas Energias: trazendo desenvolvimento tecnológico para o país
• Beneficiário: Ana Flávia Nogueira
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia