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Ana Paula de Carvalho Teixeirahttp://lattes.cnpq.br/0157609658246739Arilza de Oliveira PortoMarcelo Machado VianaGuilherme Ferreira de Limahttp://lattes.cnpq.br/0357579591704475Rubens Lucas de Freitas Filho2020-08-14T02:05:11Z2020-08-14T02:05:11Z2020-02-19http://hdl.handle.net/1843/33979O presente trabalho consistiu no desenvolvimento de compósitos a partir da matriz óxido de grafeno (GO) para serem aplicados em eletrodos de supercapacitores. Os supercapacitores são dispositivos eletroquímicos que conseguem armazenar grandes quantidades de energia (carga) e possuem a habilidade de liberá-la rapidamente, sendo aplicados em diversas áreas na sociedade. O desenvolvimento dos compósitos baseou-se na melhoria da quantidade de carga armazenada no eletrodo. Foi estudado o comportamento de diversas cargas adicionadas a matriz GO sendo essas cargas o nitreto de carbono (g-C3N4), nitreto de boro (BN), nanotubos de carbono helicoidais (h-CNTs), carbono mesoporo, e sulfetos metálicos de Ni e Co. A matriz GO foi obtida através da oxidação do grafite mineral pelo método de Hummers modificado. Os compósitos foram obtidos pelo método solvotérmico onde foi fixada a quantidade de 20% m/m de carga adicionada à matriz. Os compósitos foram caracterizados pelas técnicas de Difração de Raios X (DRX), Análise Termogravimétrica (TG), Espectroscopia Raman, Microscopias Eletrônicas de Varredura e Transmissão (MEV/MET), Espectroscopia de Raios X por Energia Dispersiva (EDS), Voltametria Cíclica, Curvas de carga-descarga e isotermas de adsorção e dessorção de nitrogênio. A área superficial específica foi obtida pelo método BET. Pelas caracterizações realizadas foi possível observara formação de GO com poucas camadas, e que o mesmo foi reduzido, levando a formação do óxido de grafeno reduzido (rGO), durante o preparo dos compósitos pelo método solvotérmico. Por meio da caracterização eletroquímica, os compósitos apresentaram comportamento puramente capacitivo, operando pelo mecanismo de dupla camada elétrica, no qual os sistemas rGO/CoNiS, rGO/h-CNT/CoS, rGO/CoS e rGO/h-CNT apresentaram capacitância específica de 292, 173, 150 e 136 F.g-1 respectivamente. Os compósitos apresentaram melhorias nas suas capacitâncias específicas se comparada a matriz GO, e mostraram ser candidatos promissores a serem aplicados como eletrodos para supercapacitores.The present work consisted in the development of composites using graphene oxide as matrix (GO) to be applied as supercapacitor electrodes. Supercapacitors are electrochemical energy storage devices that can store large amounts of energy (charge) and can release this stored energy quickly, being applied in several areas of society. The development of composites was based on the improvements of charge storaged of the electrode, and for this purpose the behavior of several charges added to the GO matrix was studied, with these charges being carbon nitride (g-C3N4), boron nitride (BN), helical carbon nanotubes (h-CNTs), mesoporous carbon, and metallic Ni and Co sulfides. The GO matrix was obtained through the oxidation of mineral graphite by the modified Hummers method. The composites were obtained by the solvothermal method in which the amount of 20% w/w of load was fixed to matrix. The composites were characterized by the techniques of X-Ray Diffraction (XRD), Thermogravimetric Analysis (TG), Raman Spectroscopy, Scanning and Transmission Electron Microscopies (SEM / TEM), X-ray Spectroscopy by Dispersive Energy (EDS), Cyclic Voltammetry, charge-discharge curves and nitrogen adsorption and desorption isotherms. The specific surface area was obtained using the BET method. Through the characterizations performed it was possible to observe the formation of GO with few layers, and that it was reduced, leading to the formation of reduced graphene oxide (rGO), during the preparation of the composites by the solvothermal method. Through electrochemical characterization, the composites showed a purely capacitive behavior, operating by the double layer electrical mechanism, in which the rGO/CoNiS, rGO/h-CNT/CoS, rGO/CoS and rGO/h-CNT systems showed specific capacitance of 292, 173, 150 and 136 F.g-1 respectively. The composites showed improvements in their specific capacitances when compared to the GO matrix, and showed to be promising candidates to be applied as electrodes for supercapacitors.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorporUniversidade Federal de Minas GeraisPrograma de Pós-Graduação em QuímicaUFMGBrasilICX - DEPARTAMENTO DE QUÍMICAQuímica inorgânicaCompósitosGrafenoNanotubos de carbonoCapacitoresSulfetosCompósitosÓxido de grafeno (GO)Sulfetos metálicos (Ni/Co)Nanotubos de carbono helicoidaisSupercapacitoresSíntese e aplicação de compósitos baseados em sulfetos metálicos, estruturas de carbono e nitretos em supercapacitores de alto desempenhoinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFMGinstname:Universidade Federal de Minas Gerais (UFMG)instacron:UFMGORIGINALDissertação Final após correções Rubens Lucas de Freitas Filho Vfinal.pdfDissertação Final após correções Rubens Lucas de Freitas Filho Vfinal.pdfapplication/pdf7334246https://repositorio.ufmg.br/bitstream/1843/33979/1/Disserta%c3%a7%c3%a3o%20Final%20ap%c3%b3s%20corre%c3%a7%c3%b5es%20Rubens%20Lucas%20de%20Freitas%20Filho%20Vfinal.pdf374bc68cefdd2a47b22cf375aff32a3dMD51LICENSElicense.txtlicense.txttext/plain; charset=utf-82119https://repositorio.ufmg.br/bitstream/1843/33979/2/license.txt34badce4be7e31e3adb4575ae96af679MD521843/339792020-08-13 23:05:11.232oai:repositorio.ufmg.br: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Repositório InstitucionalPUBhttps://repositorio.ufmg.br/oaiopendoar:2020-08-14T02:05:11Repositório Institucional da UFMG - Universidade Federal de Minas Gerais (UFMG)false
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