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Abstract Specific plasma engineering based synthesis can induce interesting photocatalytic antibacterial activities in TiO 2 films. This work presents the combination of pulsed DC (PDC) plasma with inductively coupled plasma (ICP) to synthesize undoped and nitrogen doped (N-doped) TiO 2 thin films using magnetron sputtering. The surface properties of resulting films were systematically analyzed in detail and correlated to the photocatalytic antibacterial activity against Gram negative Escherichia coli (E.coli). The addition of ICP source to PDC discharge generated TiO 2 films with enriched surface roughness due to the bombardment of highly activated species on the substrate. The ICP assisted films exhibited the morphology of nanoclusters with clear defined boundaries, higher O content and higher surface wettability. It was found that the films deposited with N-doping and addition of ICP source significantly increased the eradication of bacteria both in dark as well as in white light (artificial indoor light). Higher antibacterial activity of N-doped TiO 2 films in white light has been explained by photocatalytic degradation mechanism. Graphical abstract Image 1 Highlights • N-doped TiO 2 films have been deposited with tunable surface topography. • The surface topography and surface chemistry have been tailored through precise control of plasma species. • The high energy plasma produces the surfaces with higher wettability. • N-doped films with higher surface roughness exhibit significantly enhanced photocatalytic antibacterial activity. [ABSTRACT FROM AUTHOR]

Abstract: Ag:ZrO2 nanocomposite thin films have been synthesized by a modified sol–gel technique. The effect of post-deposition treatments i.e. thermal annealing and UV irradiation on micro-structural, chemical and optical properties of nanocomposite thin films have been studied by a transmission electron microscope, X-ray photoelectron spectrophotometer and UV–vis spectrophotometer. Films deposited with a polymeric ZrO2 sol containing Ag+ ions when treated with either thermal annealing or with UV irradiation exhibit formation of Ag:ZrO2 nanocomposite thin films via decomposition of Ag2O3 into metallic Ag. The formed Ag nanoparticles are found predominantly in spherical shape and density of Ag nanoparticles increases with increase in annealing duration for a particular concentration of Ag precursor. A protocol is provided to tailor the surface plasmon resonance-induced absorption peak at wavelength from 454 to 586nm. These nanocomposite thin films show saturable absorption and exhibit high value of non-linear absorption coefficient. [ABSTRACT FROM AUTHOR]