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Homogeneous penetration of atmospheric pressure uniform air plasma (APUAP) into thin gaps is highly warranted for multipurpose processing of materials. Here, we report APUAP generation in a 7 mm discharge gap with ambient air as the working gas, well beyond the presently maximum achievable 4 mm. Driven by a short pulse high voltage power, a 7 mm wide and 60 mm long uniform air plasma sheet is generated. The discharge is robust and the uniformity is not affected by the complex and variable components of ambient air, as is the case for most plasma discharges in air. Ultrafast photography shows that, different from previous reports, the discharge initiates in the whole air gap simultaneously and brightens quickly with the fast rise of the pulsed voltage. The generation of uniform plasma is mainly attributed to the high density of seed electrons and the reduced number density of molecules in air. Moreover, the achievable gas temperature of up to 1300 K indicates that this type of plasma is suitable for processing of a broad range of materials. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have applications in plasmonics, medicine, catalysis and electronics. We report a simple, cost-effective, facile and reproducible technique to synthesise silver nanoparticles via plasma-induced non-equilibrium liquid chemistry with the absence of a chemical reducing agent. Silver nanoparticles with tuneable sizes from 5.4 to 17.8 nm are synthesised and characterised using Transmission Electron Microscopy (TEM) and other analytic techniques. A mechanism for silver nanoparticle formation is also proposed. The antibacterial activity of the silver nanoparticles was investigated with gram-positive and gram-negative bacteria. The inhibition of both bacteria types was observed. This is a promising alternative method for the instant synthesis of silver nanoparticles, instead of the conventional chemical reduction route, for numerous applications. [ABSTRACT FROM AUTHOR]

• Cold plasma was used to modify photoanodes of the SnO 2 based DSSCs. • Plasma removes hydrocarbonated and oxocarbonated species from photoanode surfaces. • N 2 plasma converts Sn into higher oxidation states and reduces oxygen vacancies. • Remarkable efficiency increasement of ~410% was achieved. Dye sensitized solar cells (DSSC) are an attractive third-generation photovoltaic technology particularly promising for operation under diffuse and lower light conditions. However, high costs of the precious metals used for sensitizing dyes and low charge generation capability parameters limit the utility of DSSCs in comparison to conventional silicon solar cells. In this study, tin oxide (SnO 2) photoelectrodes are treated with non-thermal atmospheric pressure plasmas to enhance photovoltaic performance. The effects of nitrogen and argon plasma surface treatment of photoanodes on the efficiency enhancement of DSSCs are systematically investigated by fabricating solar cells using pristine SnO 2 and plasma-treated photoanodes. Solar cells made with Eosin Y sensitized pristine SnO 2 photoanode exhibited a short circuit current density (J SC) of 1.03 mA cm−2 and an overall power conversion efficiency (PCE) of 0.30% whereas solar cells made with nitrogen plasma treated photoanode exhibited a J SC of 6.20 mA cm−2 and an overall PCE of 1.53% (4 times enhancement) under the same illumination of 100 mW cm−2 (AM 1.5). The efficiency of the solar cells fabricated with Ar plasma treated SnO 2 photoanodes also showed an enhanced power conversion efficiency. Further characterizations revealed that the surface plasma treatments increased the surface roughness of the photoanodes. Plasma treatment led to the incorporation of nitrogen species and removal of surface impurities resulting in an increase in dye adsorption in the photoanode and hence the enhancement in the efficiency of the DSSC. This study demonstrated a one-pot treatment method for efficiency enhancement which could be used in various applications such as photovoltaic, catalytic and energy generation applications including DSSCs, thin-film solar cells, perovskite solar cells, gas sensing, bio-sensing, supercapacitors, Li-ion batteries and others. [ABSTRACT FROM AUTHOR]