Experimental and Theoretical Investigations of Electronic Structure, Electrochemical Properties and Antibacterial Activity of β-Ag2MoO4

چکیده مقاله

In this investigation, a combined theoretical and experimental study on the electronic structure of (β-Ag2MoO4) nanocrystals has been employed. β-Ag2MoO4 sample were obtained by hydrothermal technique. Crystals were structurally characterized by XRD pattern and Rietveld refinement and the results showed the spinel-type cubic structure of β-Ag2MoO4 nanocrystals. The optical property of β-Ag2MoO4 was investigated by ultraviolet -visible diffuse reflectance spectroscopy (UV-DRS) within the range of 250-850 nm. UV-vis absorption measurements showed an optical band gap value of 3.24 eV. Transmission electron microscopy (TEM) was used to study the morphological aspects of the prepared sample.In addition, the electronic band structure, density of state (DOS) of β-Ag2MoO4 were studied by Quantum Espresso package[1] based on density functional theory (DFT). First principle calculations complement the experimental results and provide a deeper comprehension of atomic and electronic structure of β-Ag2MoO4. The calculated band structure revealed an indirect Egap of approximately 3.41 ev. According to DOS results, the energy states of valence band are basically composed of Ag 4d (4dz2 + 4dx2 − y2; 4dxz + 4dyz + 4dxy) orbitals and O 2p (2px + 2py + 2pz) orbitals. However, the conduction band composition is predominantly constituted by hybridization between Mo 4d and O 2p orbitals. Furthermore, water splitting[2] and CO2 reduction[3] were considered by electrochemical studies. Antibacterial activity of β-Ag2MoO4 against Escherichia coli as a model gram negative bacterium was demonstrated. Finally, photocatalytic property of synthesized sample demonstrated good catalytic performance for degradation of methylene blue under UV–light.