Influence of Photo-Deposited Pt and Pd onto Chromium Doped TiO2 Nanotubes in Photo-Electrochemical Water Splitting for Hydrogen Generation

Influence of Photo-Deposited Pt and Pd onto Chromium Doped TiO2 Nanotubes in Photo-Electrochemical Water Splitting for Hydrogen Generation

https://doi.org/10.3390/catal11020212

Tayebeh Sharifi, Tecush Mohammadi, Mohamad Mohsen Momeni, Hrvoje Kusic, Marijana Kraljic Rokovic, Ana Loncaric Bozic, Yousef Ghayeb

Abstract

Hydrogen (H2) is considered as an ideal fuel for the future. The photo-electrochemical (PEC) water splitting employing semiconducting materials and induced irradiation, preferably of solar spectrum, presents a viable route for H2 production. In this work, self-ordered chromium-doped TiO2 nanotube (CT) was fabricated using in-situ electro-anodization. CT surface modification was then performed by photo-deposition of Pt and Pd particles, producing Pt-CT and Pd-CT catalysts, respectively. Their morphological features, crystallinity, surface composition, and optical absorption have been inspected by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman, and UV–vis absorption spectroscopy. Linear sweep voltammetry, chronoamperometry, and open circuit potential methods have been applied to study PEC activities of Pt-CT and Pd-CT catalysts in a form of electrodes. It was found that Pt-CT and Pd-CT electrodes possess excellent photo-generated electron/hole (e−/h+) separation and transport properties. The enhanced photocurrent responses of 4 and 3 times more than that of CT are revealed for Pt-CT and Pd-CT, respectively. The activity of as-prepared Pt-CT and Pd-CT catalysts was then tested for H2 generation. The maximum amount of the evolved H2 followed decreasing order: 1.08 > 0.65 > 0.26 mL cm−2 h−1 for Pt-CT, Pd-CT, and CT electrodes, respectively, clearly showing the positive contribution of photo-deposited (nano)particles onto CT surface.

https://www.mdpi.com/2073-4344/11/2/212