Titanium dioxide (TiO2) has been widely used as an advanced semiconductor and as a white pigment for many years. In recent years, TiO2 has gained much more interest for its semiconducting properties for use as photocatalytic and photovoltaic materials. Understanding the fundamental nucleation and growth mechanisms is crucial to controlling microstructure and properties for these applications. Nanosized rutile and anatase particles were synthesized from a water-soluble titanium(IV) precursor using a hydrothermal method. The impact of various hydrothermal conditions on the formation, phase, morphology, and grain size of the TiO2 products was investigated using XRD, TEM, and FTIR. At near neutral pH, aggregated rutile rods are formed. By increasing the alkalinity of the reaction medium, the anatase phase was favored and, as expected, larger particle sizes resulted from longer duration reactions. The effects of reaction conditions are discussed with respect to coordination chemistry and coarsening mechanisms.
There are few feasible options for sorbents, which can be quickly manufactured and deployed in the event of a major oil spill and so every oil spill is an ecological disaster. This paper aims to provide an understanding of what a realistic, full-scale crude oil spill solution would look like based on the performance of the best sorbents currently available, their costs, and their advantages.Adsorbent materials or “sorbents” described here have been a recent target for research toward applications in environmental cleanup, remediation, and hazardous material containment. These materials contain many compositions, syntheses, and practical manufacturing parameters that make most of them practically and logistically unfit to tackle quantities much larger than a single barrel of oil. Different properties of crude oil and nonpolar materials, such as their viscosity, density, and weathering, can also make these materials seem attractive on a lab scale but underperform in field testing and in practical applications. This review addresses the challenges, advantages, and disadvantages of different technical applications of the superior sorbent materials and material types in the literature. In addition, we discuss the different costs and manufacturing challenges of sorbent materials in real oil spills and what a feasible containment sorbent material might look like.
Lithium metal electrodes are regarded as the optimal anode for next generation lithium ion batteries especially in the lithium-sulfur architecture. Unfortunately, the lithium metal anode falls subject to several challenges such as dendrite formation and low Coulombic efficiency, which inhibit its candidacy as a viable technology. As such, substantial research efforts alter cell parameters in effort to manipulate interfacial chemistries, mitigate dendrite growth, and improve cyclability. Unlike conventional efforts, we demonstrate a practical cell operation approach to reinforce the Solid Electrolyte Interphase in lithium anodes via a refined formation protocol governed by the redox reactions found in lithium-sulfur systems. Galvanostatic and electrochemical impedance data on Li-Li symmetrical cells reveal that cell operation during the formation phase plays a critical role on interface stability of lithium metal anodes. Li-Li symmetrical cells subject to our refined protocol, P2, displayed advantages in steadily enduring high cycling currents of 6 mA with minimal polarization, and in lowering the charge transfer resistance at the cell interfaces by a fourfold when compared to cells subject to conventional formation protocols. Additionally, scanning electron microscopy images demonstrate that our formation protocol significantly minimizes the size and dispersion of lithium dendrites, as well as the degree of plated lithium. These effects are enabled by the reinforced SEI formed during P2 which offers a stable ratio between the rates of lithium intercalation to lithium deposition. Microcomputerized tomography characterization further supports these findings by revealing that P2 averts dendrite nucleation sites, and yields greater quantity of SEI species, encompassing 41.1% volume of the entire anode, compared to just 21.5% from the common formation protocol found in literature. Overall, this approach deviates from the convention of materials exploration yet highlights the importance of understanding the nature of interfacial chemistries in response to cell operation. We believe the Daisy Patino and Bo Dong contributed equally to this work.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.