Enhanced Photoinduced Electrocatalytic Oxidation of Methanol Using Pt Nanoparticle-Decorated TiO2–Polyaniline Ternary Nanofibers

Abstract Herein, perylene-3,4,9,10-tetracarboxylic acid-doped polyaniline (PTP) nanofibers with/without photoreactive anatase TiO2 (TiO2–PTP and PTP, respectively) have been successively synthesized and subsequently decorated by Pt nanoparticles (Pt NPs) to prepare Pt–PTP and Pt–TiO2–PTP composites. High-resolution transmission electron microscopy confirms the presence of ∼3 nm spherical-shaped Pt NPs on both the composites along with TiO2 on Pt–TiO2–PTP. Pt loading on the composites is deliberately kept similar to compare the methanol electro-oxidation in the two composites. The Pt nanocomposites along with the precursor polyanilines are characterized by optical characterization, X-ray diffraction study, X-ray fluorescence spectroscopy, and Raman spectroscopy. The ternary composite-modified (Pt–TiO2–PTP) electrode demonstrates high electrocatalytic performance for methanol oxidation reaction in acid medium than Pt–PTP and Pt–TiO2. The higher electrochemical surface area (1.7 times), high forward/backward current ratio, and the higher CO tolerance ability for Pt–TiO2–PTP make it a superior catalyst for methanol oxidation reaction in the electrochemical process than Pt–PTP. Moreover, the catalytic activity of Pt–TiO2–PTP is further enhanced significantly with light irradiation. The cooperative effects of photo- and electrocatalysis on methanol oxidation reaction in Pt–TiO2–PTP enhance the methanol oxidation catalytic activity approximately 1.3 times higher in light illumination than in dark. Therefore, the present work will be proficient to get a light-assisted sustainable approach for developing the methanol oxidation reaction activity of Pt NP-containing catalysts in direct methanol fuel cells.