Controlling the optoelectronic and anti-icing properties of two-dimensional materials by functionalization

Research on two-dimensional (2D) materials has exploded since 2004, when A. Geim and K. Novoselov demonstrated the remarkable properties graphene, which they had successfully isolated by using scotch tape. Subsequently, the research community has shown great interest to explore others 2D materials, namely transition metal dichalcogenides (TMDs), hexagonal boron nitride (h-BN), black phosphorus (BP), germanene and MXenes. Their physical and chemical properties identify them as promising candidates for application in electronic devices, sensors, catalytists, and coatings. We start in Chapter 1 by providing a general introduction to the field and explain the primary objective of this Ph.D. research project. Chapter 2 outlines the experimental details relative to the projects we report on in this thesis. Chapter 3 focuses on the growth of MoS2 by chemical vapour deposition. In Chapter 4, we describe how to identify the intrinsic defects of MoS2 grown by chemical vapour deposition with the help of X-ray photoelectron spectroscopy. In Chapter 5 we expand our study on surface functionalization of MoS2 grown by chemical vapour deposition. In Chapter 6, we shift our focus on another 2D material namely graphene and report on the wetting properties of a coating based on graphene oxide layer for anti-icing applications

Temperature-Adaptive Ultralubricity of a WS₂/a-C Nanocomposite Coating:Performance from Room Temperature up to 500 °c

[Image: see text] This study reports on the ultralubricity of a high-temperature resilient nanocomposite WS(2)/a-C tribocoating. The coefficient of friction of this coating remains at around 0.02 independently of a thermal treatment up to ∼500 °C, as confirmed by high-temperature tribotests. Moreover, the coating annealed at 450 °C keeps exhibiting a similar ultralubricity when cooled back down to room temperature and tested there, implying a tribological self-adaptation over a broad temperature range. High-resolution TEM observations of the tribofilms on the wear track unveil that WS(2) nanoplatelets form dynamically via atomic rearrangement and extend via unfaulting geometrical defects (bound by partial climb dislocations). The (002) basal planes of the WS(2) nanoplatelets, reoriented parallel to the tribo-sliding direction, contribute to a sustainable ultralubricity. The declining triboperformance beyond 500 °C is associated with sulfur loss rather than the transformation of WS(2) into inferior WO(3) via oxidation as suggested earlier. This self-adaptive WS(2)/a-C tribocoating holds promise for a constant ultralubrication with excellent thermal performance

Highly Efficient Remediation of Chloridazon and Its Metabolites:The Case of Graphene Oxide Nanoplatelets

The contamination of aqueous environments by aromatic pollutants has become a global issue. Chloridazon, a herbicide considered as harmless to the ecosystem, has been widely used in recent decades and has accumulated, together with its degradation products desphenyl-chloridazon and methyl-desphenyl-chloridazon, to a non-negligible level in surface water and groundwater. To respond to the consequent necessity for remediation, in this work, we study the adsorption of chloridazon and its metabolites by graphene oxide and elucidate the underlying mechanism by X-ray photoelectron spectroscopy. We find a high adsorption capacity of 67 g kg-1for chloridazon and establish that bonding of chloridazon to graphene oxide is mainly due to hydrophobic interaction and hydrogen bonding. These findings demonstrate the potential of graphene-based materials for the remediation of chloridazon and its metabolites from aqueous environments

Islam Agama Protes

108 hlm.; 21 cm

Islam mazhab pemikiran dan aksi

xii + 151 p.: 21 Cm

Menjadi Manusia Haji : Panduan Memahami Filosofi dan Makna Sosial di Balik Ritual-ritual Haji

286 hlm, 19 cm

Islam Mazhab Pemikiran dan Aksi

-

Ideologi Kaum Intelektual: Suatu Wawasan Islam

185 hal.: 17 c

Pemimpin Mustadh'afin: Sejarah Panjang Perjuangan Melawan Penindasan dan Kezaliman

107 hal.; 22 cm