Rapid development of the photoresponse and oxygen evolution of TiO2 nanotubes sputtered with Cr thin films realized via laser annealing

Recently, earth abundant transition metal oxides have gained particular attention as potential catalyst candidates due to their availability and low-cost comparing to substrates containing precious Pt or Au species. Herein, we present characterization of morphology, structure and electrochemical properties of pulsed 532 nm laser treated TiO2 nanotubes (NT) sputtered by the thin film of chromium. Scanning electron microscopy enables verification of the diameter and length of titania while Raman and X-ray photoelectron spectroscopies were used to evaluate crystalline phase and the oxidation state of elements, respectively. The recorded polarization curves clearly indicate that the optimized laser-treatment enhances activity towards oxygen evolution reaction (OER) of the TiO2 NT decorated with very small amount of Cr species. The analysis of Mott-Schottky plot shows significant increment in donor density (N-d) for the laser irradiated sample comparing to the one before annealing and pristine titania resulting from the effective manipulation of the electrode/electrolyte interface. Moreover, the impact of the processing parameters including energy fluence of laser beam and the thickness of sputtered Cr layer on the current density was evaluated by the electrochemical measurements performed under vis and UV-vis light. The results show promising application of direct interaction of laser beam with the surface of material exhibiting initially both poor OER activity and visible light response. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, earth abundant transition metal oxides are investigated as potential catalyst candidates for oxygen evolution reaction due to their availability and low cost. The pulsed laser treated TiO2 nanotubes sputtered with chromium layer exhibit enhanced activity towards OER and increased donor density, impacting the electrode/electrolyte interface effectively. Results show promising application of direct laser interaction with materials exhibiting poor initial OER activity and visible light response.