Impact of passivation on GaS nanoflakes: A study on stability, electronic, spectroscopy, and photocatalytic properties

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2025-02, Vol.326, p.125173, Article 125173
• Main Authors: Rai, Jyoti, Kumar, Kuldeep, Verma, Mukesh Kumar, Sharma, Munish
• Format: Article
• Language: English
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2024.125173

[Display omitted] •Passivation enhances GaS nanoflake stability, with fluorinated GaS-NF being the most stable.•Cl-GaS NF shows Negative Differential Conductance, making it useful for device switching.•Higher quantum capacitance observed in passivated GaS-NFs, beneficial for supercapacitors.•Hydrogenated GaS-NF is a highly effective photocatalyst for water splitting.•Passivation shifts absorption spectra to the visible range, enhancing applications in photovoltaics, imaging, and photocatalysis. This study uses first-principle calculations to investigate the properties of pristine and passivated gallium sulfide nanoflakes. Passivation significantly enhances stability, with fluorinated nanoflakes being the most stable and pristine nanoflakes the least stable, having formation energies of −0.058 eV/atom and −0.009 eV/atom, respectively. The pristine and passivated nanoflakes show semiconducting band gap, which lies in a visible region. Hydrogenated nanoflakes exhibit the largest band gap of 3.62 eV, making them highly suitable for photocatalysis, while fluorine and chlorine passivation result in band gaps of 3.16 eV and 3.01 eV. Scanning tunneling microscopy reveals distinct topographical features for each passivated nanoflake, affecting their electronic properties, including negative differential conductance, making it suitable for advanced switching devices and sensors. The quantum capacitance value of 815 µF/cm2 for chlorinated nanoflakes suggests that passivated nanoflakes could be beneficial for supercapacitor applications. Spectroscopic studies show that passivation changes the infrared spectrum and moves absorption spectra from the ultraviolet to the visible range. The hydrogenated nanoflakes are found ideal for water splitting, and adjusting the pH can further optimize its photocatalytic performance. These findings highlight the potential of passivated nanoflakes in photovoltaics, biomedical imaging, photocatalysis, and advanced technological devices.