Synergistic doping with Ag, CdO, and ZnO to overcome electron-hole recombination in TiO2 photocatalysis for effective water photo splitting reaction

Nehal A Erfan; Mohamed S Mahmoud; Hak Yong Kim; Nasser A M Barakat

doi:10.3389/fchem.2023.1301172

Synergistic doping with Ag, CdO, and ZnO to overcome electron-hole recombination in TiO₂ photocatalysis for effective water photo splitting reaction

Front Chem. 2023 Nov 6:11:1301172. doi: 10.3389/fchem.2023.1301172. eCollection 2023.

Authors

Nehal A Erfan¹, Mohamed S Mahmoud^{1

2}, Hak Yong Kim^{3

4}, Nasser A M Barakat¹

Affiliations

¹ Chemical Engineering Department, Minia University, El-Minia, Egypt.
² Department of Engineering, University of Technology and Applied Sciences, Suhar, Oman.
³ Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, Republic of Korea.
⁴ Department of Organic Materials and Fiber Engineering, Jeonbuk National University, Jeonju, Republic of Korea.

Abstract

This manuscript is dedicated to a comprehensive exploration of the multifaceted challenge of fast electron-hole recombination in titanium dioxide photocatalysis, with a primary focus on its critical role in advancing the field of water photo splitting. To address this challenge, three prominent approaches-Schottky barriers, Z-scheme systems, and type II heterojunctions-were rigorously investigated for their potential to ameliorate TiO₂'s photocatalytic performance toward water photo splitting. Three distinct dopants-silver, cadmium oxide, and zinc oxide-were strategically employed. This research also delved into the dynamic interplay between these dopants, analyzing the synergetic effects that arise from binary and tertiary doping configurations. The results concluded that incorporation of Ag, CdO, and ZnO dopants effectively countered the fast electron-hole recombination problem in TiO₂ NPs. Ag emerged as a critical contributor at higher temperatures, significantly enhancing photocatalytic performance. The photocatalytic system exhibited a departure from Arrhenius behavior, with an optimal temperature of 40°C. Binary doping systems, particularly those combining CdO and ZnO, demonstrated exceptional photocatalytic activity at lower temperatures. However, the ternary doping configuration involving Ag, CdO, and ZnO proved to be the most promising, surpassing many functional materials. In sum, this study offers valuable insights into how Schottky barriers, Z-scheme systems, and type II heterojunctions, in conjunction with specific dopants, can overcome the electron-hole recombination challenge in TiO₂-based photocatalysis. The results underscore the potential of the proposed ternary doping system to revolutionize photocatalytic water splitting for efficient green hydrogen production, significantly advancing the field's understanding and potential for sustainable energy applications.

Keywords: heterojunction; photocatalyst; solar irradiation; titanium oxide doping; water photo splitting.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. National Research Foundation (NRF) of Korea, Korean government (MSIT) project numbers 2022R1A2C2007676 financially supported this research.