Síntese, caracterização e aplicação do alfa-hidróxido de níquel associado a óxido de grafeno reduzido como sensor voltamétrico

• Ano de defesa: 2018
• Autor(a) principal: Silva, Aleckson Souto
• Orientador(a): Martins, Paulo Roberto
• Banca de defesa: Martins, Paulo Roberto, Sgobbi, Lívia Flório, Chagas, Rafael Pavão das
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Química (IQ)
• Departamento: Instituto de Química - IQ (RG)
• País: Brasil
• Palavras-chave em Português: Nanocompósito; Materiais nanoestruturado; Ni(OH) 2 /GO; α-Ni(OH) 2 /rGO; Sensor voltamétrico
• Palavras-chave em Inglês: Nanocomposite; Nanostructured materials; α-Ni(OH) 2 /GO; α-Ni(OH) 2 /rGO; Voltammetric sensor
• Área do conhecimento CNPq: QUIMICA::QUIMICA INORGANICA
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/8738

The present work aims to the development of voltammetric sensors based on α-Ni(OH) 2 /GO and α- Ni(OH) 2 /rGO nanocomposites for detection and determination of uric acid, paracetamol and ascorbic acid by differential pulse voltammetry. For this, nanostructured nickel hydroxide stabilized in the alpha polymorphic form associated with graphene oxide (GO) or reduced graphene oxide (rGO) were synthesized and characterized. The method used for synthesis of α- Ni(OH) 2 was Tower’s modified, for oxidized graphite was that of Hummers and reduced graphene oxide was that of Stankovich. X-ray diffractometry, confocal Raman spectroscopy, cyclic voltammetry, transmission electron microscopy, infrared spectroscopy and thermogravimetric analysis were used to characterize the synthesized nanomaterials. The presence of graphene oxide and reduced graphene oxide with nickel hydroxide was confirmed by the results. The nickel hydroxide/graphene composites arouse great interest for the development of electrochemical sensors due to their good cost-effectiveness, biocompatibility and high catalytic effect. The thin films of α-Ni(OH) 2 /GO and α-Ni(OH) 2 /rGO showed better electrical properties compared to thin film of α-Ni (OH) 2 and it can be attributed to the increase in surface area and electrical conductivity. Through the differential pulse voltammetry, α-Ni(OH) 2 /GO and α-Ni(OH) 2 /rGO films presented good linear relationship between peak current and uric acid, ascorbic acid and paracetamol concentrations in the range concentration of 0.099 mmol.L -1 – 1.38 mmol.L -1 , with linear coefficients higher than 0.993 and detection limit lower than 2,645x10 -5 mol.L -1 for uric acid, 2,080x10 -5 mol. L -1 for ascorbic acid and 4.248x10 -5 mol. L -1 for paracetamol.