The role of counter-ions in crystal morphology, surface structure and photocatalytic activity of ZnO crystals grown onto a substrate

Autor(es)

Catto, Ariadne C. ^{[1, 2]} ; Ferrer, Mateus M. ^[3] ; Lopes, Osmando F. ^{[4, 5]} ; Mastelaro, Valmor R. ^[6] ; Andres, Juan ^[7] ; da Silva, Luis F. ^[1] ; Longo, Elson ^[2] ; Avansi Jr, Waldir

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Lab Nanostruct Multifunct Mat, Rodovia Washington Luiz, Km 235, BR-13565090 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, CDMF, Rodovia Washington Luiz, Km 235, BR-13565090 Sao Carlos, SP - Brazil

^[3] Univ Fed Pelotas, Ctr Technol Dev, Grad Program Mat Sci & Engn, BR-96010610 Pelotas, RS - Brazil

^[4] Forschungszentrum Julich, Inst Energy & Climate Res IEK Electrochem Proc En, D-52425 Julich - Germany

^[5] Univ Fed Uberlandia, Inst Chem, Lab Photochem & Mat Sci, BR-38400902 Uberlandia, MG - Brazil

^[6] Univ Sao Paulo, Inst Phys Sao Carlos, Ave Trabalhador Sao Carlos, BR-13566590 Sao Carlos, SP - Brazil

^[7] Univ Jaume 1, Dept Quim Fis & Anal, E-12080 Castellon de La Plana - Spain

• Tipo de documento: Artigo Científico
• Fonte: Applied Surface Science; v. 529, NOV 1 2020.
• Citações Web of Science: 0

Resumo

In this contribution, we present an experimental and theoretical investigation of the role of counter-ions in the crystal morphology, surface structure, and photocatalytic activity of hierarchical ZnO nanostructures. The effect of zinc precursor (nitrate, acetate and, sulfate) along the synthesis of ZnO nanostructures grown directly onto a substrate by means of a simple hydrothermal method was analyzed in detail. Scanning electron microscopy images showed a preferential growth of ZnO nanostructures along the c-axis, with a slight reduction in the orientation depending on the choice of the Zn source. Theoretical calculations based on the Wulff theory allowed us to better understand the morphological changes and directly relate the photocatalytic performance at the different exposed surfaces of the as-observed crystal shapes. Our results showed that photocatalytic activities in the discoloration of organic dyes became superior for hierarchical ZnO nanostructures obtained from zinc nitrate. This finding was explained by X-ray photoelectron and photoluminescence spectroscopies, which revealed that in addition to, the attached counter-ions and the abundance of carboxylate groups and organic residuals on ZnO surfaces, the presence of surface defects are determinant to enhance the photocatalytic performance of the material. (AU)

• Processo FAPESP: 18/18208-0 - Heteroestruturas a-Fe2O3/g-C3N4: Preparação, Caracterização e Aplicação como Sensores Resistivos de Gás
• Beneficiário: Ariadne Cristina Catto
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/12437-5 - Preparação e caracterização de nanoheterojunções semicondutoras aplicadas como sensores resistivos de gás fotoativados
• Beneficiário: Luís Fernando da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/13888-0 - Síntese de nano-heteroestruturas de BiVO4/óxidos de bismuto e avaliação de suas propriedades fotocatalíticas.
• Beneficiário: Osmando Ferreira Lopes
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• 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: 12/15170-6 - Síntese e caracterização de filmes finos e espessos de ZnO: aplicação como sensores de gás
• Beneficiário: Ariadne Cristina Catto
• Modalidade de apoio: Bolsas no Brasil - Doutorado