Reduced graphene oxide enhancing the photoelectrochemical properties of poly(3-hexylthiophene)

Poly(3-hexylthiophene) has been used in different photoelectrochemical devices as active material. However, its efficiency regarding photo-conversion is low and the coupling with a second compound is necessary to reduce the electron-hole recombination effect on the generation of photocurrent. The low efficiency could be related to the organization of the polymer. In this work, we propose the use of reduced graphene oxide as modifier to P3HT to enhance its photocatalytic properties. The results here obtained strong suggest, both theoretically and experimentally, an important change in the polymer chain organization from twisted to planar configuration. As consequence, an important increase in the photoelectrochemical properties were observed. In the present case an improvement of over 50% in the value of the photocurrent comparing the pure material and the binary one, processed under the same conditions. In addition, the half-life of the charge carrier increased substantially from 0.781 ms to 9.54 ms. The results are promising because they demonstrate that a higher organization level of the polymer chains increases the photocatalytic properties of the material. Furthermore, the theoretical study not only explains why the properties are improved, but also leads to new understanding of the electronic structure obtained in a binary material.