Tuning photocatalytic performance via oxygen vacancies and in situ ZnS formation on ZnO for hydrogen evolution
Year: 2025
Type: article
Abstract: The quest for renewable energy solutions drives research into photocatalytic materials for hydrogen evolution, with zinc oxide (ZnO) emerging as a promising candidate. This study systematically examines the structural, optical, and photocatalytic properties of ZnO and oxygen-deficient ZnO x , synthesized via the hydrothermal method. Powder X-ray diffraction (P-XRD) reveals a crystal phase transition from the Zn(OH) 2 to ZnO 2 precursor, evolving into wurtzite ZnO and ZnO x . UV–Vis DR spectroscopy indicates enhanced visible light absorption and narrowed band gaps in ZnO x , suggesting improved photocatalytic water splitting capabilities. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) confirm the presence of oxygen vacancies and Zn +2 ions in the lattice. Transmission electron microscopy (TEM) shows well-faceted crystals with size increases at higher annealing temperatures. Oxygen-deficient ZnO annealed at 400 °C (ZnO x -400) exhibits superior photocatalytic hydrogen production efficiency (5780 μmol g −1 cat ), emphasizing the critical role of oxygen vacancies in enhancing activity. Under alkaline sulfide environments, in situ ZnS formation on ZnO surfaces creates stable ZnS/ZnO composite structures, enhancing photocatalyst durability and recyclability. This study underscores the importance of oxygen vacancies, ZnS formation, and structural tuning in optimizing ZnO for visible-light-driven hydrogen evolution, advancing renewable energy solutions.
Source: Renewable Energy
Authors: Adarsh K. Mourya, Rudra P. Singh, Mohd Amin, Sakshi R. Barad, Mohammadmahdi Abedi, Atul V. Wankhade
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,460
OpenAlex ID: W4409500564