Theoretical and experimental study of solar cells based on nanostructured films of TiO2 sensitized with natural dyes extracted from Zea mays and Bixa orellana

Natural dyes were extracted from Zea mays and Bixa orellana, products from Peru, for the sensitization of nanoporous titanium dioxide (TiO2) films.

Metal–organic framework-derived nanoporous titanium dioxide–heteropoly acid composites and its application in esterification

MIL-125(Ti) metal–organic framework-derived nanoporous titanium dioxide–heteropoly acid (PW–TiO2) have been synthesized by a facile hydrothermal approach and subsequent calcination, and the PW–TiO2 catalysts were investigated using various characterization technologies including FTIR, XRD, SEM, TEM, N2-physisorption, and NH3-TPD. Further, we investigated the use of PW–TiO2 composites as heterogeneous acid catalysts for the catalytic esterification of oleic acid. Among all series of catalysts, the calcined PW–TiO2 at a temperature of 350°C showed excellent activity with a high conversion of 90.5% at 160°C for 4 h. More importantly, the catalyst could be simply separated via centrifugation and reused for six cycles and shows a relatively high conversion of 74.8%.