Incorporation of Cu5FeS4 QDs with Abundant Oxygen Vacancy TiO2 QDs/TiO2 OVs: Double S-Scheme Photocatalysts for Effectual N2 Conversion to NH3 under Simulated Solar Light

Khadijeh Pournemati; Aziz Habibi-Yangjeh; Alireza Khataee

doi:10.1021/acs.inorgchem.4c00440

Incorporation of Cu₅FeS₄ QDs with Abundant Oxygen Vacancy TiO₂ QDs/TiO₂ OVs: Double S-Scheme Photocatalysts for Effectual N₂ Conversion to NH₃ under Simulated Solar Light

Inorg Chem. 2024 Apr 15;63(15):6957-6971. doi: 10.1021/acs.inorgchem.4c00440. Epub 2024 Apr 4.

Authors

Khadijeh Pournemati¹, Aziz Habibi-Yangjeh¹, Alireza Khataee^{2

3}

Affiliations

¹ Department of Chemistry, Faculty of Science, University of Mohaghegh Ardabili, 56199-13131 Ardabil, Iran.
² Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, 51666-16471 Tabriz, Iran.
³ Department of Chemical Engineering, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey.

PMID: 38576059
DOI: 10.1021/acs.inorgchem.4c00440

Abstract

Photocatalytic N₂ conversion to NH₃ is a green, sustainable pathway with renewable energy sources and carbon neutrality. In this research, ternary TiO₂ QDs/TiO₂ OVs/Cu₅FeS₄ nanocomposites were prepared by an easy and affordable procedure and utilized to produce clean ammonia energy without a sacrificial agent. The amount of produced green ammonia by the optimum nanocomposite achieved was 17,274 μmol L^-1 g^-1, which was approximately 20.9, 6.48, 4.45, 2.26, and 1.45 times higher than those of commercial TiO₂, TiO₂ QDs, TiO₂ OVs, Cu₅FeS₄, and TiO₂ QDs/TiO₂ OVs photocatalysts, respectively. Lattice compatibility through the developed homojunction within TiO₂ QDs/TiO₂ OVs and the integration of Cu₅FeS₄ nanoparticles led to the establishment of a double S-scheme homo/heterojunction system, which improved the photocatalytic activity by maintaining electrons and holes with high oxidation and reduction power and greatly reduced the recombination of charges, which led to the acceleration of charge transfer and migration. Besides, the promoted surface area compared to the pure components, introducing oxygen vacancies, and reducing the particle size boosted the photocatalytic N₂ conversion to NH₃. The results of this research are a basis for the rational design of homojunction/heterojunction visible-light-responsive systems for photocatalytic nitrogen fixation reactions.