CVD grown 2D MoS2 layers: A photoluminescence and fluorescence lifetime imaging study

In this letter, we report on the fluorescence lifetime imaging and accompanying photoluminescence properties of a chemical vapour deposition (CVD) grown atomically thin material, MoS2. µ-Raman, µ-photoluminescence (PL) and fluorescence lifetime imaging microscopy (FLIM) are utilized to probe the fluorescence lifetime and photoluminescence properties of individual flakes of MoS2 films. Usage of these three techniques allows identification of the grown layers, grain boundaries, structural defects and their relative effects on the PL and fluorescence lifetime spectra. Our investigation on individual monolayer flakes reveals a clear increase of the fluorescence lifetime from 0.3 ns to 0.45 ns at the edges with respect to interior region. On the other hand, investigation of the film layer reveals quenching of PL intensity and lifetime at the grain boundaries. These results could be important for applications where the activity of edges is important such as in photocatalytic water splitting. Finally, it has been demonstrated that PL mapping and FLIM are viable techniques for the investigation of the grain-boundaries. (Figure presented.). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Anaerobic Digestion of Aquatic Plants for Biogas Production

7th Global Conference on Global Warming (GCGW) -- JUN 24-28, 2018 -- Izmir, TURKEYWOS: 000587895700012Limited reserves of fossil fuel resources and negative environmental impacts increased energy demands toward renewable energy technologies. Bioenergy is one of the solutions, and biogas production from wastes and residues by anaerobic digestion (AD) is a promising technology. Municipal solid wastes, sludge from wastewater treatment plants, agricultural plant wastes, forestry residues and manure are the widely used sources in AD for biogas production. Aquatic plants can be evaluated as a renewable energy source. If waste and residues of these plants are not utilized in beneficial use, greenhouse gases (GHG) will be emitted through land-filling or direct combustion. Wastes should be converted to biogas with a high yield to decrease the quantity of wastes and biogas with a high-energy content. Substrate to inoculum ratio, temperature regime, C/N ratio, pH, volatile fatty acid and ammonia content are important process parameters for AD. Modified Gompertz, Cone and first-order equations are widely used model equations for kinetic parameters that are used in kinetic models (Monod, modified Andrew, Ratkowsky) for identification of optimum substrate concentration and temperature for each specific feed. This chapter evaluates effective process parameters on AD of aquatic plants for biogas production and application of kinetic analysis for assignment of optimum conditions.Scientific and Technological Research Council ofTurkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114Y500]; Ministry of Science, Industry and Technology of Turkish Republic [0330.STZ.2013-2]The authors acknowledge the Scientific and Technological Research Council ofTurkey (TUBITAK, Project No: 114Y500) for the financial support. We also thankThe Ministry of Science, Industry and Technology of Turkish Republic supporting our preliminary tests through the grant so-called SAN-TEZ (Project No: 0330.STZ.2013-2). We are grateful to IZSU Ci.gli Advanced BiologicalWastewater Treatment Plant, Izmir for giving us waste sludge for biogas production. We thank to Mr. G. Serin, M.Sc. students M. C. Akbas and B. Kaletas for assistance in laboratory studies. the authors acknowledge publisher "John Wiley and Sons" for permission of reuse of full article Gungoren Madeno.glu et al. [7]