The control over contagious diseases caused by pathogenic organisms has become a serious health issue. The extensive usage of antibiotics has led to the development of multidrug-resistant bacterial strains. In this regard, metal-oxide-based antibacterial nanomaterials have received potential research interest due to the efficient prevention of microorganism growth. In this study, splat-shaped Ag–TiO2 nanocomposites (NCs) were synthesized on the gram scale and the enhanced antibacterial properties of TiO2 in the presence of silver were examined. The formation of Ag–TiO2 NCs was analyzed through various characterization techniques. The cell viability experimental results demonstrated that the Ag–TiO2 NCs have good biocompatibility. The antibacterial activity of the prepared Ag–TiO2 NCs was tested against the Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacterial strains. The Ag–TiO2 NCs exhibited promising and superior antibacterial properties compared to TiO2 nanospheres as confirmed by the bacterial growth and inhibition zone. The improvement in the antibacterial activity was attributed to the synergistic effect of the hybrid nature of TiO2 nanoparticles in the presence of Ag.

We report a selectivity‐switchable nickel hydride‐catalyzed methodology that enables the stereocontrolled semi‐reduction of internal alkynes to E‐ or Z‐alkenes under very mild conditions. The proposed transfer semi‐hydrogenation process involves the use of a dual nickel/photoredox catalytic system and triethylamine, not only as a sacrificial reductant, but also as a source of hydrogen atoms. Mechanistic studies revealed a pathway involving photo‐induced generation of nickel hydride, syn‐hydronickelation of alkyne, and alkenylnickel isomerization as key steps. Remarkably, mechanistic experiments indicate that the control of the stereoselectivity is not ensuing from a post‐reduction alkene photoisomerization under our conditions. Instead, we demonstrate that the stereoselectivity of the reaction is dependent on the rate of a final protonolysis step which can be tuned by adjusting the pKa of an alcohol additive.