Enhancement of photocurrent response for self-ordered Nb2O5 nanotubes synthesized at room temperature

Autor(es)

de Brito, Juliana Ferreira ^[1] ; Mascaro, Lucia Helena ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Chem, Rod Washington Luiz, Km 235, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Materials Science; v. 56, n. 3, p. 2088-2102, JAN 2021.
• Citações Web of Science: 0

Resumo

The major challenge regarding new photocatalysts is to obtain a semiconductor with high and stable photocurrent from inexpensive and abundant materials. Niobium oxide meets some of these requirements, but its photocurrent is usually very low. Therefore, this study introduces the synthesis and characterization of self-organized Nb(2)O(5)nanotubes (Nb(2)O(5)Nt) presenting a high photocurrent density of 0.04 mA cm(-2)under incidence of artificial sunlight, of 100 mW cm(-2), and potential of 1.5 V without further surface modification. The best catalyst was obtained through anodization of a Nb foil at 90 V for 2 h in a one-compartment and two-electrodes cell at room temperature, using glycerol, H2O, and NH4F as the electrolyte, followed by annealing at 450 degrees C for 60 min. The water concentration was the most important factor to obtain the desired morphology with a good distribution of nanotube diameters, high UV absorption, low bang gap (3.2 eV) compared to the observed for the Nb2O5 semiconductor (3.4 eV), and great photocurrent density. Such properties turn the Nb(2)O(5)Nt into a promising catalyst for direct use in photochemical reactions or as a good platform yet to be combined in heterojunctions or applied for doping and decoration. (AU)

• Processo FAPESP: 14/50249-8 - Green chemistry: sustainable synthetic methods employing benign solvents, safer reagents, and bio-renewable feedstock
• Beneficiário: Arlene Gonçalves Corrêa
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 18/02950-0 - Redução fotoeletrocatalítica de N2 a NH3 em reator fotoeletroquímico com fotoânodo direcionador de elétrons de Nb2O5/Pt e cátodo de GDL decorado com Fe, Co e Sb2Se3
• Beneficiário: Juliana Ferreira de Brito
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• 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
• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 18/16401-8 - Fotocatalisadores e fotoeletrodos para obtenção de combustíveis renováveis
• Beneficiário: Lucia Helena Mascaro Sales
• Modalidade de apoio: Auxílio à Pesquisa - Regular