DFT and molecular docking insights into barium- and polyacrylic acid-integrated nickel selenide for efficient dye reduction and biological applications.

The escalating discharge of industrial waste has hampered access to clean and potable water. This study aims to explore the potential use of nanomaterials for eliminating organic pollutants and harmful microbes such as Escherichia coli (E. coli) from wastewater. Nickel selenide (NiSe) doped with varying concentrations (2% and 4%) of barium (Ba2+) and a fixed concentration (3%) of polyacrylic acid (PAA) was synthesized via a coprecipitation route. An array of cutting-edge characterization techniques were employed to analyze the crystallographic structure, morphological features, elemental composition, molecular vibrations and optical properties of the synthesized NSs. 4% Ba/PAA-doped NiSe displayed significant catalytic activity (CA) against rhodamine B (RhB) dye, exhibiting a removal efficiency of 85.37% under neutral conditions, attributed to energy level adjustments and morphological transformation caused by dopants (PAA and Ba2+). Furthermore, a potent bactericidal effect was shown against E. coli, with an inhibition zone of 6.90 mm. The inhibitory effect of Ba/PAA-doped NiSe NSs on DNA gyrase in E. coli was elucidated by molecular docking investigations, which validated their bactericidal activity. The DFT investigation, including MESP, HOMO, and LUMO analyses, provided significant insights into the electronic structure and active compound reactivities.