The Role of the Ferroelectric Polarization in the Enhancement of the Photocatalytic Response of Copper-Doped Graphene Oxide-TiO2 Nanotubes through the Addition of Strontium

Nuhad Abdullah Alomair; Nouf Saleh Al-Aqeel; Sanaa Saad Alabbad; Hafedh Kochkar; Gilles Berhault; Muhammad Younas; Fathi Jomni; Ridha Hamdi; Ismail Ercan

doi:10.1021/acsomega.2c06717

The Role of the Ferroelectric Polarization in the Enhancement of the Photocatalytic Response of Copper-Doped Graphene Oxide-TiO₂ Nanotubes through the Addition of Strontium

ACS Omega. 2023 Feb 24;8(9):8303-8319. doi: 10.1021/acsomega.2c06717. eCollection 2023 Mar 7.

Authors

Nuhad Abdullah Alomair^{1

2}, Nouf Saleh Al-Aqeel^{1

2}, Sanaa Saad Alabbad¹, Hafedh Kochkar^{1

2}, Gilles Berhault³, Muhammad Younas⁴, Fathi Jomni⁵, Ridha Hamdi², Ismail Ercan⁶

Affiliations

¹ Department of Chemistry, College of Science, Imam Abdulrahman Bin Faisal University, P. O. Box 1982, 31441 Dammam, Saudi Arabia.
² Basic & Applied Scientific Research Center, Imam Abdulrahman Bin Faisal University, P. O. Box 1982, 31441 Dammam, Saudi Arabia.
³ Institut de Recherches sur la Catalyse et l'Environnement de Lyon, CNRS-Université Lyon I, 69100 Villeurbanne, France.
⁴ Core Research Facilities, King Fahd University of Petroleum and Minerals, 31261 Dhahran, Saudi Arabia.
⁵ Départment de Physique, Faculté des Science de Tunis, Université Tunis El Manar, Campus Universitaire, Tunis 1002 Tunisia.
⁶ Department of Electrical and Electronics Engineering, Faculty of Engineering, Düzce University, Düzce 81010, Turkey.

Abstract

To evaluate the potential role of in situ formed Sr-Ti-O species as a ferroelectric component able to enhance the photocatalytic properties of an adjacent TiO₂ semiconductor, Cu-doped/graphene oxide (GO)/TiO₂ nanotubes (TiNTs) composites (with 0.5 wt % Cu and 1.0 wt % GO) have been synthesized while progressive amounts of strontium (up to 1.0 wt %) were incorporated at the surface of the composite through incipient wetness impregnation followed by post-thermal treatment at 400 °C. The different resulting photocatalytic systems were then first deeply characterized by means of N₂ adsorption-desorption measurements, X-ray diffraction (XRD), UV-vis diffuse reflectance (UV-vis DR), Raman and photoluminescence (PL) spectroscopies, and scanning electron microscopy (SEM) (with energy-dispersive X-ray (EDX) spectroscopy and Z-mapping). In a second step, optimization of the kinetic response of the Sr-containing composites was performed for the formic acid photodegradation under UV irradiation. The Sr-containing Cu/GO/TiNT composites were then fully characterized by electrochemical impedance spectroscopy (EIS) for their dielectric properties showing clearly the implication of polarization induced by the Sr addition onto the stabilization of photogenerated charges. Finally, a perfect correlation between the photocatalytic kinetic evaluation and dielectric properties undoubtedly emphasizes the role of ferroelectric polarization as a very valuable approach to enhance the photocatalytic properties in an adjacent semiconductor.