Separation and Purification Technology, Vol.193, 358-367, 2018
Fabrication of ternary polyaniline-graphene oxide-TiO2 hybrid films with enhanced activity for photoelectrocatalytic hydrogen production
In this work, the polyaniline-graphene oxide-TiO2 (PANI/GO/TiO2) ternary hybrid films have been successfully fabricated on ITO electrodes via self-deposition of TiO2, GO and in-situ electropolymerization of aniline in a controllable method. The microstructures, morphologies, and photoelectrochemical properties of the as-prepared PANI/GO/TiO2 films in different multi-layer structure were characterized and evaluated systematically. The experimental results showed that the additions of GO and PANI endow the films visible-light responsive activity. Then the hybrid films were employed for the first time as photoanode in photoelectrocatalytic (PEC) water reduction for the hydrogen generation. Compared with pristine TiO2 electrode, the ternary hybrid films with alternative GO, TiO2 and outer PANI layer presented the best PEC activity, and by which the hydrogen generation rate is higher than most of the reported TiO2-based nanophotocatalysts. PEC mechanism analysis suggested that an efficient charge transfer would occur at the interface of PANI and GO/TiO2 due to the matched band potentials, and PANI served as the roles of both electron collector and transporter, so the collected electrons readily transferred to the counter electrode under a certain bias voltage to reduce water into H-2. In addition, the results of the contrast experiments demonstrated that the used electrolyte also played an important role in PEC water reduction, and the seawater might be an ideal medium for PEC process. This study is meaningful for the development of other new photoanode materials for PEC hydrogen generation.
Keywords:Photoelectrocatalysis;Hydrogen generation;Hybrid films;Layer-by-layer;Polyaniline-graphene oxide-TiO2