Thesis Type: Postgraduate
Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, ENERJİ SİSTEMLERİ MÜHENDİSLİĞİ ANABİLİM DALI, Turkey
Approval Date: 2024
Thesis Language: Turkish
Student: FATİH HİMMET
Supervisor: Gökhan Sürücü
Open Archive Collection: AVESIS Open Access Collection
Abstract:This thesis aims to investigate sustainable and environmentally friendly photocatalytic materials for green hydrogen production through water splitting; it presents an evaluation of single-layer two-dimensional (2D) structures such as WSi2N4 and Janus-type WSiGeN4 within the framework of Density Functional Theory (DFT). The mechanical, dynamic, electronic, and optical properties of WSi2N4 and WSiGeN4 materials have been thoroughly examined, and their promising potential for photocatalytic water splitting applications has been determined. The thermodynamic stability of these materials at 300 K has been confirmed through machine learning force fields (MLFF) supported Ab Initio Molecular Dynamics (AIMD) simulations. Extensive optimization and analyses have shown that these single layers possess advantageous properties such as suitable electronic band gaps, stable work functions, and durability over a wide pH range, which are critically important for the hydrogen evolution reaction (HER). As both HER and the oxygen evolution reaction (OER) have been observed on various chemical surfaces in photocatalytic applications, the WSiGeN4 2D Janus structure has been obtained by doping the WSi2N4 structure with Ge atoms to optimize reaction environments and catalytic processes. The inclusion of WSiGeN4 has significantly enhanced photocatalytic efficiency, meeting the optimal redox reaction levels in both conductivity and valence bands. Additionally, analyses have revealed that these materials possess high absorption capacity in the visible spectrum, which is critical for solar-powered photocatalytic applications.