Danae J. Davis

Lithographically defined three-dimensional graphene structures.

A simple and facile method to fabricate 3D graphene architectures is presented. Pyrolyzed photoresist films (PPF) can easily be patterned into a variety of 2D and 3D structures. We demonstrate how prestructured PPF can be chemically converted into hollow, interconnected 3D multilayered graphene structures having pore sizes around 500 nm. Electrodes formed from these structures exhibit excellent electrochemical properties including high surface area and steady-state mass transport profiles due to a unique combination of 3D pore structure and the intrinsic advantages of electron transport in graphene, which makes this material a promising candidate for microbattery and sensing applications.

Graphene-Ni-α-MnO2 and -Cu-α-MnO2 nanowire blends as highly active non-precious metal catalysts for the oxygen reduction reaction.

Graphene-like carbon-Ni-α-MnO(2) and -Cu-α-MnO(2) blends can serve as effective catalysts for the oxygen reduction reaction with activities comparable to Pt/C.

New multi-electron high capacity anodes based on nanoparticle vanadium phosphides

Nanoscale vanadium phosphides can serve as new high capacity anodes in alkaline aqueous electrolytes. Competing corrosion reaction(s) are mitigated with the novel use of an anion exchange membrane providing for capacities as high as 2800 mAh g(-1) @ 100 mA g(-1) discharge rate.

Thermal Stability of Oxide-Based Solar Selective Coatings for CSP Central Receivers

Efforts at Sandia National Laboratories are addressing more efficient solar selective coatings for tower applications, based on oxide materials deposited by a variety of methods. Over the course of this investigation, several compositions with optical properties competitive to Pyromark have been identified. These promising coatings were deposited on Inconel 625 and Haynes 230 Ni alloys and isothermally aged in air at temperatures between 600–800 °C for up to 480 hours, concurrently with Pyromark®, which was used as a reference standard. At various heating times, the samples were removed from the furnace and their optical properties (solar-weighted absorptance and emittance) were measured. In addition, x-ray diffraction and scanning electron microscopy were utilized to investigate any structural or morphological changes that occurred over time with heating, in an attempt to correlate with changes in optical properties. At 600 and 700 °C, several of the coatings maintained an absorptivity > 90%. While the chemical makeup of the coating material greatly influences its optical properties, the morphology of the surface also plays in important part. A thermal sprayed coating modified using a novel laser treatment showed improved properties versus the untreated coating, on par with Pyromark™ at 600 °C, with little degradation after 480 hours. The results of aging on the optical, structural, and morphological properties of these novel coatings will be discussed.Copyright