研究目的

The main objective is to combine these both approaches to interpret the different adsorption isotherms of Paprika oleoresin dye (Capsicum annuum L) into TiO2 mesoporous at three temperatures: 288 K, 298 K, and 308 K.

研究成果

The adsorption process of paprika dye on TiO2 surface has been investigated by using a combination between the statistical physics modeling and a DFT simulation. The statistical physics treatment and the results of fitting showed that the developed of monolayer model with four energies is able to predict the microscopic topography and the geometry of the adsorbed dye molecules on TiO2. The stenographic and energetic parameters which deduced by this best fitting model have allowed physical interpretations and discussions describing the adsorption process of the paprika oleoresin dye on the TiO2 surface at the three different temperatures. The adsorption geometry was described by the number of molecules per site and showed that the dye molecules can be anchored on the TiO2 mesoporous with the two parallel and nonparallel configurations. From the energetic viewpoint, the calculated adsorption energies values revealed that the dye is adsorbed physically and chemically on the TiO2 surface. The DFT simulation has been carried out in order to complete this statistical physics investigation by studying the interaction of the Paprika dye on TiO2 surface to understand some of the atomistic details that are crucial to the dye/ semiconductor interaction. The DFT simulation has determined different binding modes which participate in the adsorption of Paprika dye on TiO2 surface. In particular, the interaction between the paprika dye and TiO2 is strengthened with the bidentate coordination mode via the two hydroxyl and ether functionalities groups involving in the adsorption process.

研究不足

The study focuses on the adsorption process of Paprika dye on TiO2 for dye sensitized solar cells, and the limitations are not explicitly mentioned in the abstract.