Desenvolvimento de um nanocompósito a base de azo polímero funcionalizado com grafeno como fotossensibilizador para célula solar
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Data
2021-03-01
Autores
Pacheco, Jessica Crivelaro
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Universidade Estadual Paulista (Unesp)
Resumo
O presente trabalho de pesquisa tem por objetivo demonstrar os resultados obtidos com o estudo e desenvolvimento de um nanocompósito formado a partir de um azo polímero funcionalizado com grafeno como fotossensibilizador para célula solar. Para esta finalidade, estudou-se os filmes poliméricos de poli(azo-Bismarck R), poli(azoBismarck Y) e os nanocompósitos poli(azo-Bismarck R)-rGO e poli(azo-Bismarck Y)- rGO, que foram preparados por técnica de voltametria cíclica sobre eletrodo de óxido de estanho dopado com flúor (FTO). O estudo da resposta fotoeletroquímica dos filmes foi realizado pelas técnicas de voltametria cíclica, cronoamperometria e espectroscopia de impedância eletroquímica (EIS). Como resultado obteve-se os parâmetros eletroquímicos otimizados para preparação dos filmes poliméricos de BBR e BBY e de seus nanocompósitos. Foi possível verificar um aumento da fotocorrente gerada pelos filmes dos nanocompósitos otimizados em relação aos filmes poliméricos, o que foi atribuído a interação stacking π-π existente entre as folhas de grafeno e as camadas do polímero. Foi observado também, um aumento de quatro vezes o valor da fotocorrente gerada pelo poli(azo-Bismarck Y), quando comparada à fotocorrente gerada pelo poli(azo-Bismarck R). Isso foi associado às mudanças nas propriedade ópticas do polímero, causadas pelo grupo metila, doador de densidade eletrônica, que está presente na estrutura do monômero do Bismarck Brown R e que pode ter influenciado de forma negativa na obtenção de fotocorrente para o poli(azoBismarck R). Os interessantes resultados de resposta fotoeletroquímica obtidos para o nanocompósito poli(azo-Bismarck Y)-rGO, permitiram sua aplicação como fotossensibilizador em uma célula solar do tipo DSSC. O poli(azo-Bismarck Y)-rGO se mostrou um promissor material para essa finalidade, assim como para aplicação em outros dispositivos fotovoltaicos.
This research work aims to demonstrate the results obtained with the study and development of a nanocomposite formed from an azo polymer functionalized with graphene as a photosensitizer for the solar cell. For this purpose, we studied the polymeric films of poly(azo-Bismarck R), poly(azo-Bismarck Y) and poly(azo-Bismarck R)-rGO and poly(azo-Bismarck Y)-rGO nanocomposites, which were prepared by cyclic voltammetry on a fluorine doped tin oxide (FTO) electrode. The photoelectrochemical response of the films was performed using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy (EIS). As result, the optimized electrochemical parameters were obtained for the preparation of polymeric films of BBR and BBY and their nanocomposites. It was possible to verify an increase in the photocurrent generated by the nanocomposite films optimized in relation to the polymeric films, which was attributed to the π-π stacking interaction between the graphene sheets and the polymer layers. It was also observed, an increase of four times the value of the photocurrent generated by the poly(azoBismarck Y), when compared to the photocurrent generated by the poly(azo-Bismarck R). This was associated with changes in the optical properties of the polymer, caused by the methyl group, an electronic density donor, which is present in the structure of the Bismarck Brown R monomer and which may have negatively influenced the photocurrent for the poly(azo-Bismarck R). The interesting results of photoelectrochemical response obtained for the poly(azo-Bismarck Y)-rGO nanocomposite, allowed its application as a photosensitizer in a DSSC type solar cell. The poly(azo-Bismarck Y)-rGO proved to be a promising material for this purpose, as well as for application in other photovoltaic devices.
This research work aims to demonstrate the results obtained with the study and development of a nanocomposite formed from an azo polymer functionalized with graphene as a photosensitizer for the solar cell. For this purpose, we studied the polymeric films of poly(azo-Bismarck R), poly(azo-Bismarck Y) and poly(azo-Bismarck R)-rGO and poly(azo-Bismarck Y)-rGO nanocomposites, which were prepared by cyclic voltammetry on a fluorine doped tin oxide (FTO) electrode. The photoelectrochemical response of the films was performed using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy (EIS). As result, the optimized electrochemical parameters were obtained for the preparation of polymeric films of BBR and BBY and their nanocomposites. It was possible to verify an increase in the photocurrent generated by the nanocomposite films optimized in relation to the polymeric films, which was attributed to the π-π stacking interaction between the graphene sheets and the polymer layers. It was also observed, an increase of four times the value of the photocurrent generated by the poly(azoBismarck Y), when compared to the photocurrent generated by the poly(azo-Bismarck R). This was associated with changes in the optical properties of the polymer, caused by the methyl group, an electronic density donor, which is present in the structure of the Bismarck Brown R monomer and which may have negatively influenced the photocurrent for the poly(azo-Bismarck R). The interesting results of photoelectrochemical response obtained for the poly(azo-Bismarck Y)-rGO nanocomposite, allowed its application as a photosensitizer in a DSSC type solar cell. The poly(azo-Bismarck Y)-rGO proved to be a promising material for this purpose, as well as for application in other photovoltaic devices.
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Palavras-chave
Nanocompósito, Óxido de grafeno reduzido, Azo polímero, Fotossensibilizador, Célula solar sensibilizada por corante, Nanocomposite, Reduced graphene oxide, Azo polymeren, Photosensitizer, Dye-sensitized solar cell