Hexagonal CeO2 and Eu-doped CeO2 nanoparticles were obtained using a facile microwave-hydro thermal method under mild conditions and their application towards manganese redox flow battery component were studied. The s...Hexagonal CeO2 and Eu-doped CeO2 nanoparticles were obtained using a facile microwave-hydro thermal method under mild conditions and their application towards manganese redox flow battery component were studied. The structural properties were studied by X-ray diffraction and indicate that samples present a fluorite structure. Raman spectroscopy shows Eu3＋ ions substitute Ce4＋ and generate oxygen vacancies. Electrochemical properties of pure and Eu-doped CeO2 films deposited at graphite substrates investigated by cyclic voltammetry and galvanostatic charge-discharge indicate that dopant concentration affects the electrochemical properties of CeO2. The increase in the reversibility redox of electrochemical systems observed is attributed to coexistence of Ce4＋/Ce3＋ redox couple confirmed by XPS.Charge-discharge tests display coulombic and voltage efficiency values of above 80% and 90%, respectively. The obtained specific capacity for Ce（0.99）Eu（0.01）O2（372.49 mAh/g） and pure oxide（334.84 mAh/g）indicates that both samples are promising for application in Mn-batteries.展开更多
基金Project supported by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior(Capes)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)+2 种基金Fundaao de AmparoàPesquisa do Estado de Minas Gerais(FAPEMIG)Rede Mineira de Química(RQ-MG)Grupo de Materiais Inorgnicos do Tringulo-GMIT Research Group supported by FAPEMIG(APQ-00330-14)
文摘Hexagonal CeO2 and Eu-doped CeO2 nanoparticles were obtained using a facile microwave-hydro thermal method under mild conditions and their application towards manganese redox flow battery component were studied. The structural properties were studied by X-ray diffraction and indicate that samples present a fluorite structure. Raman spectroscopy shows Eu3＋ ions substitute Ce4＋ and generate oxygen vacancies. Electrochemical properties of pure and Eu-doped CeO2 films deposited at graphite substrates investigated by cyclic voltammetry and galvanostatic charge-discharge indicate that dopant concentration affects the electrochemical properties of CeO2. The increase in the reversibility redox of electrochemical systems observed is attributed to coexistence of Ce4＋/Ce3＋ redox couple confirmed by XPS.Charge-discharge tests display coulombic and voltage efficiency values of above 80% and 90%, respectively. The obtained specific capacity for Ce（0.99）Eu（0.01）O2（372.49 mAh/g） and pure oxide（334.84 mAh/g）indicates that both samples are promising for application in Mn-batteries.
