30^th World Nano Conference May 20-21, 2019 Zurich, Switzerland

Photocatalytic reduction of nitro-aromatics to industrially important amino-derivatives using greener process  attracted a great deal of research interest as compared to conventional synthetic techniques. In this context, this research will show some potential usage of different sizes and shapes of bare and metal loaded TiO2, nanostructures (1-4) for the improved photoreduction efficiency of nitroaromatics under solar irradiation. It observed that anisotropic and core-shell nanostructures displaying superior catalysis and photocatalysis properties than conventional bulk catalysts materials. Photocatalytic reduction of 25 μmol 2, 2'-dinitrobiphenyl in 50% aqueous isopropanol and 50 mg P25-TiO2 under an argon atmosphere and 20 h UV light irradiation selectively produced 23.8 μmol of benzo [c] cinnoline (95%), (scheme 1) and 2, 2'-biphenyldiamine (5%) whose amount gradually increased with the irradiation time beyond 20–24 h due to further reduction of benzo [c] cinnoline. Selective photoreduction of mono/dinitro benzene to nitroanline and diaminobenzene etc could be controlled by crystal phases and shapes of TiO2 nanoparticles both under UV and solar irradiation. Highly sunlight photoactive Aloe-veral shaped crystalline rutile TiO2 nanoarchitectures is found to have superior hydrogenation efficiency of different nitroaromatics than conventional P25 and rutile TiO2 under direct sunlight exposure. Cu nanostructures of various shapes and sizes as superior catalysts for nitro-aromatic reduction and co-catalyst for Cu/TiO2 photocatalysis. Likewise core shell and lenghty nanostructures of mono and bimetallic plasmonic nanocatalysts exhibited better selectivity and yield for nitroaromatices reduction.

Yoshitaka Okada completed his PhD degree in electronic engineering from the University of Tokyo. He is currently a Professor in the Department of New Energy at the Research Center for Advanced Science and Technology (RCAST) of the University of Tokyo. His recent research interests include epitaxial film growth of low-dimensional quantum nanostructures as well as III-V-N dilute nitrides for applications to high efficient intermediate-band and hot carrier solar cells and multijunction solar cells. Dr. Okada is a member of the IEEE, Materials Research Society (MRS) and Japan Society of Applied Physics (JSAP). He has authored and co-authored over 200 refereed journal publications and over 230 international conference presentations.

Significant efforts have been devoted in order to demonstrate operation of quantum dot intermediate band solar cells (QD-IBSCs) [1]. The challenge for QD-IBSCs is to establish methods to fabricate high-density QDs arrays of low defect density with long carrier lifetimes. The areal density of QDs has direct influence on the generation and recombination processes via IB states since the total density of states of IB (NIB) is linked to the areal density Nareal as NIB = Nareal × Nstacks / W, where Nstacks is the number of QD layer stacks and W is the width QD region, respectively. For this, we have shown that strain-compensated growth improves the QDs quality and characteristics of InAs/GaAs QDSCs with Nstacks up to 100 in self-organized heteroepitaxy by MBE. However, the average QD size prepared by such dry methods is still large and Nareal is low, typically limited to the range of 15-30 nm and 1011- 1012 cm-2, respectively. Furthermore, strain-induced bandgap widening of InAs QDs reduces the offset between the barriers, which results in an increased thermal escape of carriers out of QDs thereby reducing photocurrent production by 2-step photoabsorption (TSPA). In this work, optimization of QD-IBSC structure is studied for which PbS colloidal QDs of 4 nm in size were densely dispersed in a bulk CH3NH3PbBr3 perovskite matrix with a high energy bandgap of 2.4eV [2]. We focus on the TSPA characterization performed at room temperature.

 

Recent Publication

1. Y. Okada et al, Appl. Phys. Rev. 2, 021302 (2015). [2] H. Hosokawa et al, Nature Commun. (2019). DOI:

10.1038/s41467-018-07655-3.

Xidong Duan is a Professor at the College of Chemistry and Chemical Engineering, Hunan University, China. His current research interests include twodimensional materials, heterostructures and their applications. He received his BS degree in Chemistry from Hunan University in 1993, his MA degree in Materials from Hunan University in 1996, and his degree in Chemistry from Hunan University in 2016. He was previously a senior engineer at the Changsha Research Institute of Mining and Metallurgy before joining Hunan University.

Two-dimensional layered materials such as garphene, MoS2 and WSe2 have attracted considerable interest in recent times as semiconductor after Si and becoming an important material platform in condensed matter physics and modern electronics and optoelectronics. The studies to date however generally rely on mechanically exfoliated flakes which always be limtited to simple 2D materals, especially 2D lateral complicated structure can not be perpared through exfoliation strategy. Much like the traditional semiconductor technique, complicated structure such as controlling the space distribution of composition and electronic structure of two dimensional semiconductor material is essential to construct all modern electronic and optoelectronic devices, including transistors, p–n diodes, photovoltaic/photodetection devices, light-emitting diodes and laser diodes. And many physics phenomenon can only appear in more complicated structure. To fully explore the potential of this new class of materials, it is necessary to develop rational synthetic strategies of two dimensional lateral complicated struture, such as lateral heterostructure, multiheterostructure, superlattice, quantum well etc., With a relatively small lattice mismatch (~4%) between MoS2 and MoSe2 or WS2 and WSe2, it is possible to produce coherent MoS2–MoSe2 and WS2–WSe2 heterostructures through a lateral epitaxial process (Fig. 1a). Our studies indicate that simple sequential growth often fails to produce the desired heterostructures because the edge growth front can be easily passivated

after termination of the first growth and exposure to ambient conditions. To retain a fresh, unpassivated edge growth front is important for successive lateral epitaxial growth. To this end, we have designed a thermal CVD process that allows in situ switching of the vapour-phase reactants to enable lateral epitaxial growth of single- or few-layer TMD lateral heterostructures. We used this technique to realize the growth of compositionally modulated MoS2– MoSe2 and WS2–WSe2 lateral heterostructures. From the Fig. 1 b,c,d,e we can see the formation of WS2–WSe2 lateral heterostructures clearly. The WS2–WSe2 lateral heterostuctures with both p- and n-type characteristics can also allow us to construct many other functional devices, for example, a CMOS inverter. Fig. 1g is the optical image of the invert constructed using the WS2–WSe2 lateral heterostuctures and the curves of the output–input and the voltage gain. The voltage gain reaches as large as 24.

Mirko ÄŒernák is a professor at the Department of Physical Electronics, Faculty of Science, Masaryk University, Brno, Czech Republic. He is also the director of the R&D Centre for Low-cost Plasma and Nanotechnology Surface Modifications (CEPLANT) at Masaryk University. His research interests include the fundamental study of high pressure electrical discharges, plasma chemistry, and applied plasma physics. He has published more than 100 papers in the scientific journals and has been cited more than 2100 times, H-index: 24

Because of their unique properties known only in ceramic materials the mesoporous ceramic nanofibres (CNFs) have been developed for many advanced materials applications in energy harvesting systems, batteries, catalysts, sensors to mention just a few. The usual way to fabricate CNFs consists of a sol-gel electrospinning procedure followed by a thermo-calcination process performed at temperatures up to 800°C for several hours. The slow thermocalcination is the bottleneck in potential in-line or even continuous production, which significantly adds to the cost of CNFs and products manufactured therefrom. An additional problem is that the high calcination temperature is prohibitive in the preparation of inorganic nanofibres layers on heat-sensitive substrates and problematic in adhesion of the nanofibres to metal substrates. A novel fast ambient-air plasma technique enables the calcination at near-room temperatures and times less than 30 min that opens opportunities for the low-cost continuous manufacturing of thin CNFs mats and layers. Moreover to enhance the nanofibres flexibility the plasma calcination enables to manufacture organic/inorganic nanofibres with the core-shell structure. The results on plasma-calcination of TiO2 and Al2O3 CNFs will be presented.

Gunther holds an engineer diploma in Chemistry & Plastic technology and bachelor in Safety advisor (2005). With over 10 years of invaluable experience in SHEQ managing projects and resources in an effective and efficient manner. Highly focused with a comprehensive knowledge and understanding of various industries and sectors such as plastic engineering, automotive, trailer building, composite engineering/ development, chemical industry, logistics, Operational services and consulting. As a true professional he is always willing to challenge the status quo and improve on existing standards. Since June 2016 he joined the company OCSiAl as a H&S manager, responsible for the regulatory affairs worldwide.

The company OCSiAl is been founded in 2009 and is also the first SWCNT manufacturer who has completed his EU-REACH registration for a tonnage band of up to 10T/a and is planning to receive approval for a tonnage band up to 100T/y by the end of Q3/2019. At the end of the 2017 we achieved our signed consent order with the EPA that allows us to import up to 25T/y. Because Tuball™ is used and also tested in various applications on an ongoing basis, also receiving a lot of interests worldwide. That is why it is obvious that the company OCSiAl is establishing the necessary regulatory and quality standards worldwide. The first part of this presentation will aim at providing a short introduction of our Tuball™ substance and his product line, a second part of the presentation will be about the morphology vs Health & Safety status, the third part is an overview about the status and plans of the ongoing registrations an compliance. The fourth and last part of the presentation will focus on the health, safety and environmental aspects of our Tuball™ substance and the different applications. As SWCNT manufacturer, OCSiAl is doing continues investments in improving our understanding of our different (new) Tuball products themselves and potential hazards through their (entire) life cycle. We are involved in generating additional test data and collaborating with industry associations and networks. This presentation will describe the steps being taken by the company’s H&S Lead manager, Van Kerckhove Gunther to successfully introduce our carbon nanotubes (SWCNT’s) regulatory status and outline our (future) plans for numerous of studies and qualifying our Tuball™ substance including the different kind of compositions.

Elisabetta Travaglia is a research fellow at CNR-IOM Trieste, working within the H2020 European project NFFA Europe, where she deals with the technical aspects of transnational access to the laboratories, and actively takes part to the management of the whole project. Elisabetta has a master degree in Chemistry and a PhD degree in Nanotechnology, both obtained at the University of Trieste. Since several years she has been involved in dissemination and outreach activities both for experts and general public, also addressing children to show them that science is fun.

NFFA-Europe is a European open-access resource for experimental & theoretical nanoscience that carries out comprehensive projects for multidisciplinary research at the nanoscale ranging from synthesis to nanocharacterization, to theory and numerical simulation. Advanced infrastructures specialized on growth, nano-lithography, nano-characterization, theory and simulation and fine-analysis with Synchrotron, FEL and Neutron radiation sources are integrated into a multi-site combination to develop frontier research on methods for reproducible nanoscience research thus enabling European and international researchers from diverse disciplines to carry out advanced proposals impacting on science and innovation. NFFA-Europe coordinates access to infrastructures on different aspects of nanoscience research that are not currently available at single specialized sites without duplicating specific scopes. Internationally peer-reviewed approved user projects have access to the best suited instruments, competences and technical support for performing research, including access to analytical large scale facilities, theory and simulation and high-performance computing facilities. Access is offered free of charge to European users. Two researchers per user group are entitled to receive partial financial contribution towards the travel and subsistence costs incurred. The user access scheme includes at least two “installations” and is coordinated via a single entry point portal that activates an advanced user-infrastructure dialogue to build up a personalized access programme with an increasing return on science and innovation production. NFFA-Europe’s own research activity addresses key bottlenecks of nanoscience research: i.e. nanostructure traceability, protocol reproducibility, in-operando nano-manipulation and analysis, open data.

The alternative conception of "black body" (in the wave diffraction sense) is represented in this article for electromagnetic waves. For many decades, many researchers have tried to find a structure (constant in time, and with field representation by complex amplitudes at any frequency) of an absorbing shell that would satisfy simultaneously (jointly) the following conditions: (a) effective absorption; (b) a spatial ultra-wide absorption band (i.e. the absorption efficiency is independent of the spatial frequency or of incident wave direction), (c) an ultra-wide absorption temporal frequency band (i.e. the absorption efficiency does not depend on the incident wave time frequency), (d) the small thickness of the absorbing coating compared to the length of the absorbed wave and to the geometric dimension of protected body. But without full success, because any wave to be absorbed need time (more or equal to its period) and distance (more or equal to its wavelength) to have time to make a work (if we do not make conversion its frequency) on the absorber. Now remind that in all these years microelectronic technologies (designed for computational purposes and according the law Gordon Moore) have been intensively developed: the miniature and rate of the element base (or the spatial-temporal resolution). On the other hand wavelengths that were intended to be absorbed by the “black” shells remained the same due to the constant conditions of the long-range propagation of these waves. 

This work is an attempt to use the great successes of microelectronics to satisfy conditions (a)-(d) jointly. The required level of nano-electronics development is very high, but quite real today. Spatial interior construction of black body is presented by thin micro-structure having boundaries like foam or, in other words, air cavities or cells (virtual resonators with oscillatory fading) separated from each other by very thin walls of controlled transparency. Temporal control of these boundaries (walls) is very fast periodical switching between nonreflecting (opened, transparent, isolated metal needles) and the reflecting (closed, opaque, like metal grid, united metal needles) states of walls. During transparent state the structure the structure lets in itself an incident wave without scattering. At the beginning of the reflecting state of the foam walls, “instant metallization” of walls splits the instant spatial distribution of incident wave into a lot small pieces which become the initial conditions of oscillations inside the virtual resonators. The minimum own frequency of the any virtual resonator (metal cavity) is very higher than the inverse duration of incident wave propagation though the thickness of the foam-like shell. So any part of incident wave, which came into the shell, has enough time to be absorbed. And energy of incident wave scattered by shell in its reflecting state can be much less than the energy absorbed by virtual resonators if the duration of transparent state (in each period of switching) is very greater then the reflecting state duration. Thus, the virtual resonator is a special nano-electronic chip, which does not process signals, but is a direct participant in life of waves to be absorbed.