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van der Waals gap engineering of graphite and vermiculite using electric fields and intercalants for separation applications
No full textStability and Electronic Properties of SnS/ZnS Interfaces: A First-Principles Investigation
No full textIn this study, we investigate the stability and electronic properties of bulk, surface, and interface structures between tin sulfide (SnS) and zinc sulfide (ZnS) by using first-principles calculations and high-throughput interface structure search methods. Our analysis reveals significant differences in the electronic structures of these materials, with distinct bandgaps observed for SnS and ZnS in bulk and surface configurations as well as at their pristine interface. The pristine SnS/ZnS interface exhibits a staggered (type-II) band alignment, which is favorable for solar cell applications. We further explore the impact of interface defects, finding that an equal distribution of atoms from both SnS and ZnS surfaces at the interface offers optimal stability and maintains semiconducting properties. In contrast, interfaces with an excess of any single element tend to exhibit metallic characteristics. These findings highlight the critical role of atomic composition in the design of stable and efficient SnS/ZnS interfaces, paving the way for improved thin-film solar cell performance
Safe and Sustainable by Design MOF Beads for Selective Entrapment and Recovery of Rare Earth Elements
No full textWe report the development of CA-BNMG-1 composite beads-cellulose acetate macrobeads embedded with nanosized copper imidazolate MOFs (BNMG-1) -engineered via nonsolvent-induced phase separation for the selective recovery of rare earth elements (REEs) from complex aqueous environments. This encapsulation strategy ensures uniform MOF dispersion, enhanced mechanical integrity, and minimized Cu(II) leaching (<1%), fulfilling the Safe and Sustainable by Design (SSbD) criteria. The CA matrix not only mitigates copper toxicity but also enables facile bead handling, recyclability, and scalable deployment in fixed-bed systems. Adsorption studies across a 10-REE standard solution and two simulated waste streams demonstrated significantly improved REE selectivity over pristine BNMG-1. Separation factors (SFs) for Yb(III) over Mn(II), Ni(II), and Na(I) reached 194.5, 325.8, and 339, respectively; Eu(III) showed SFs of 155.5, 260.5, and 271.2. The beads retained over 95% of their uptake capacity across multiple adsorption and single desorption cycles using mild acidic eluents, confirming excellent reusability and structural stability. This work advances a robust, low-toxicity, and scalable REE recovery platform that integrates adsorptive performance with environmental safety. CA-BNMG-1 beads offer a compelling alternative to solvent extraction, with potential for integration into circular economy strategies targeting REE recovery from e-waste, mine tailings, and industrial effluents-addressing both resource security and sustainability challenges
Intermittent Control in Autonomous Vehicle Steering Control and Lane Keeping
No full textIntermittent control is a control approach in which a continuous control law is applied, but is switched on and off based on a threshold criteria in the controlled variable. Evidence of intermittency in control strategies employed by humans in various tasks have been reported widely, however, an analysis of why an intermittent controls strategy might be advantageous even when an continuous control strategy is feasible, is not widely available. In vehicle steering control, empirical data suggests that humans indeed use an intermittent strategy. In this paper, we examine this question of advantages of an intermittent control strategy with the help of typical vehicle steering control and lane keeping problems. Using simulation results, we generate insights related to stability, robustness and energy efficiency of intermittent control over continuous control. These insights may have immediate applications to autonomous driverless cars and other wider range of applications. � 2022 Elsevier B.V., All rights reserved
Nanosheets Derived from Titanium Diboride as Gate Insulators for Atomically Thin Transistors
No full textDevelopment and integration of gate insulators that offer a low equivalent oxide thickness (EOT) while maintaining a physically thicker layer are critical for advancing transistor technology as device dimensions continue to shrink. Such materials can deliver high gate capacitance and yet reduce gate leakage, thereby minimizing static power dissipation without compromising performance. These insulators should also provide the necessary interface quality, thermal stability, switching endurance, and reliability. Here, we demonstrate that nanosheets derived from titanium diboride (NDTD), synthesized at room temperature using a scalable dissolution-recrystallization method, exhibit EOT ∼ 2 nm irrespective of the physical thickness when used as top gate dielectrics for monolayer MoS2 field effect transistors (FETs). Furthermore, these nanosheets enable near-ideal subthreshold swing of 60 mV/decade, low gate leakage current (-4 A/cm2), and current on/off ratio of 106 at a supply voltage of 1 V, indicating clean interface and excellent electrostatic control. These titanium diboride (TiB2) derived nanosheet-gated MoS2 FETs also demonstrate stable operation at 125 °C and switching endurance in excess of 109 cycles. While nanosheets derived from metal diborides have been employed in energy storage, catalysis, and CO2 capture, this study showcases their potential as excellent gate insulators for microelectronics
An analysis of heterogeneous catalytic activity of transition metal - carbon composites and thiospinels towards electrochemical energy generation
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