Engineering Commons^™

Recent Advances In Graphene-Based Materials For Fuel Cell Applications, Hanrui Su, Yun Hang Hu

Michigan Tech Publications

The unique chemical and physical properties of graphene and its derivatives (graphene oxide, heteroatom-doped graphene, and functionalized graphene) have stimulated tremendous efforts and made significant progress in fuel cell applications. This review focuses on the latest advances in the use of graphene-based materials in electrodes, electrolytes, and bipolar plates for fuel cells. The understanding of structure-activity relationships of metal-free heteroatom-doped graphene and graphene-supported catalysts was highlighted. The performances and advantages of graphene-based materials in membranes and bipolar plates were summarized. We also outlined the challenges and perspectives in using graphene-based materials for fuel cell applications.

Synthesis And Characterization Of Free-Stand Graphene/Silver Nanowire/Graphene Nano Composite As Transparent Conductive Film With Enhanced Stiffness, Chuanrui Guo, Yanxiao Li, Yanping Zhu, Chenglin Wu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As-grown graphene via chemical vapor deposition (CVD) has potential defects, cracks, and disordered grain boundaries induced by the synthesis and transfer process. Graphene/silver nanowire/graphene (Gr/AgNW/Gr) sandwich composite has been proposed to overcome these drawbacks significantly as the AgNW network can provide extra connections on graphene layers to enhance the stiffness and electrical conductivity. However, the existing substrate (polyethylene terephthalate (PET), glass, silicon, and so on) for composite production limits its application and mechanics behavior study. In this work, a vacuum annealing method is proposed and validated to synthesize the free-stand Gr/AgNW/Gr nanocomposite film on transmission electron microscopy (TEM) grids. AgNW …

Synthesis And Characterization Of Free-Stand Graphene/Silver Nanowire/Graphene Nano Composite As Transparent Conductive Film With Enhanced Stiffness, Chuanrui Guo, Yanxiao Li, Yanping Zhu, Chenglin Wu, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As-grown graphene via chemical vapor deposition (CVD) has potential defects, cracks, and disordered grain boundaries induced by the synthesis and transfer process. Graphene/silver nanowire/graphene (Gr/AgNW/Gr) sandwich composite has been proposed to overcome these drawbacks significantly as the AgNW network can provide extra connections on graphene layers to enhance the stiffness and electrical conductivity. However, the existing substrate (polyethylene terephthalate (PET), glass, silicon, and so on) for composite production limits its application and mechanics behavior study. In this work, a vacuum annealing method is proposed and validated to synthesize the free-stand Gr/AgNW/Gr nanocomposite film on transmission electron microscopy (TEM) grids. AgNW …

Corrosion-Induced Mass Loss Measurement Under Strain Conditions Through Gr/Agnw-Based, Fe-C Coated Lpfg Sensors, Chuanrui Guo, Liang Fan, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, graphene/silver nanowire (Gr/AgNW)-based, Fe-C coated long period fiber gratings (LPFG) sensors were tested up to 72 hours in 3.5 w.t% NaCl solution for corrosion-induced mass loss measurement under four strain levels: 0, 500, 1000 and 1500 µ∈. The crack and interfacial bonding behaviors of laminate Fe-C and Gr/AgNW layer structures were characterized using Scanning Electron Microscopy (SEM) and electrical resistance measurement. Both optical transmission spectra and electrical impedance spectroscopy (EIS) data were simultaneously measured from each sensor. Under increasing strains, transverse cracks appeared first and were followed by longitudinal cracks on the laminate layer structures. The spacing …

Carbon-Based Interlayers In Perovskite Solar Cells, Aleksandr P. Litvin, Xiaoyu Zhang, Kevin Berwick, Anatoly V. Fedorov, Weitao Zheng, Alexander V. Baranov

Articles

Perovskites are solution-processed, high-performance semiconductors of interest in low-cost photovoltaics. The interfaces between the perovskite photoactive layers and the top and bottom contacts are crucial for efficient charge transport and minimizing trapping. Control of the collection of charge carriers at these interfaces is decisive to device performance. Here, we review recent progress in the realization of efficient perovskite solar cells using cheap, easily processed, stable, carbon-based interlayers. Interface materials including graphene, carbon nanotubes, fullerenes, graphene quantum dots and carbon dots are introduced and their influence on device performance is discussed.

Adhesion Of Two-Dimensional Titanium Carbides (Mxenes) And Graphene To Silicon, Yanxiao Li, Shuohan Huang, Congjie Wei, Chenglin Wu, Vadym Mochalin

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Two-dimensional transition metal carbides (MXenes) have attracted a great interest of the research community as a relatively recently discovered large class of materials with unique electronic and optical properties. Understanding of adhesion between MXenes and various substrates is critically important for MXene device fabrication and performance. We report results of direct atomic force microscopy (AFM) measurements of adhesion of two MXenes (Ti₃C₂T_x and Ti₂CT_x) with a SiO₂ coated Si spherical tip. The Maugis-Dugdale theory was applied to convert the AFM measured adhesion force to adhesion energy, while taking into account …

Crumpled Graphene Oxide: Aerosol Synthesis And Environmental Applications, Yi Jiang

McKelvey School of Engineering Theses & Dissertations

Environmental technologies, such as for water treatment, have advanced significantly due to the rapid expansion and application of nanoscale material science and engineering. In particular, two-dimensional graphene oxide (GO), has demonstrated considerable potential for advancing and even revolutionizing some of these technologies, such as engineered photocatalysts and membranes. To realize such potential, an industrially scalable process is needed to produce monomeric and aggregation-resistant GO nanostructures/composites, in addition to new knowledge of material properties, behavior, and performance within an environmental context.

Research presented in this thesis addresses both scientific and engineering gaps through the development of a simple, yet robust aerosol-based …

Adsorption Of Halogenated Aliphatic Contaminants By Graphene Nanomaterials: Comparison With Carbon Nanotubes And Granular Activated Carbons, Yang Zhou

All Theses

Graphene nanomaterials are two-dimensional single layer sp2 hybridized carbon atoms densely packed in a hexagonal honeycomb lattice and can be visualized as basic building blocks for fullerenes, carbon nanotubes (CNTs), and graphite. In addition, they are hydrophobic nanomaterials and possess a large specific surface area (SSA), thus they have been evaluated as promising adsorbents to remove synthetic organic compounds (SOCs) from water. As with granular activated carbons (GACs) and CNTs, adsorption behavior of SOCs on graphene depends on the physicochemical properties of the adsorbents (e.g., specific surface area, pore size distribution and surface chemistry), SOCs (e.g., hydrophobicity, molecular size and …