As amostras de ZnO sintetizadas com diferentes concentrações do líquido iônico TEA-PS.BF4 apresentaram pureza superior a 93 % em uma única fase, conforme con- firmado pela técnica de difração de raios X. O refinamento dos dados de DRX evidenciou a influência do LI no tamanho do cristalito, na microdeformação e na anisotropia da rede cris- talina. O tamanho do cristalito aumentou com a adição do líquido iônico enquanto a aniso- tropia e a microdeformação diminuíram, já que ao aumentar o tamanho do cristalito espera- se a redução de tensões internas na estrutura.
Em relação aos filmes confeccionados, observou-se um aumento da poro- sidade para a amostra com 5 % de LI e analogamente verificou-se um aumento do tamanho médio dos poros. A espectroscopia Raman dos filmes mostrou um aumento do tamanho do cristalito com o aumento da concentração do líquido iônico, reafirmando os resultados ob- servados com o refinamento dos dados de DRX.
A caracterização eletroquímica das células evidenciou a melhoria do fo- toânodo com 5 % de LI, que apresentou uma eficiência de 2,23 % e densidade de corrente de 7,13 mA.cm-², já que em comparação ao fotoânodo sem líquido iônico tem-se uma efici- ência de 1,93 % e densidade de corrente de 4,11 mA.cm-². Observou-se, por espectroscopia de impedância eletroquímica, que o líquido iônico contribuiu para aumento da resistência a transferência de carga, ou seja, diminui a recombinação na interface semicondutor/eletrólito do dispositivo.
Dessa forma, concluiu-se que o líquido iônico influência a estrutura cris- talina e morfologia do óxido de zinco, promovendo a melhora nas respostas eletroquímicas de CSSC nas quais esse material foi aplicado, quando utilizado na proporção de 5 % (m/m). Sugere-se uma análise mais detalhada em relação à porosidade dos filmes, utilizando técni- cas como BET, bem como a análise dos mecanismos cinéticos de oxidação e redução durante a fotoconversão. Além disso, para melhorar a reprodutibilidade da confecção das CSSC’s se faz necessário um estudo reológico da suspensão, visando a otimização e padronização dos filmes.
Nos trabalhou futuros sugere-se alterar a proporção de líquido iônico du- rante a síntese, realizando um planejamento experimental para uma análise estatística das respostas exploradas neste trabalho.
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