Nanostructured zinc oxide–chromophore hybrid films with multicolored electrochromic properties

We describe the synthesis and the electrochromic properties of hybrid films made of zinc oxide and different tetrasulfonated metallophthalocyanines (M-TSPc with M = Ni, Co and Fe). We show that the films deposited electrochemically by a one-step method at 70 °C are well-crystallised, porous and nanostructured. By this means a large amount of phthalocyanine can be immobilized and fixed in a transparent inorganic matrix. Moreover, these molecules are electrochemically active and the films can be considered for potential applications in electrochemical devices. In phosphate buffer, we show that by changing the applied potential toward negative potential, the color of the bulk films can be monitored. The color transitions and the potentials for these transitions are a function of the metal in the complex.