Browsing by Author "Thakur, Anupma"

Now showing 1 - 4 of 4
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    Review—Combining Experimental and Engineering Aspects of Catalyst Design for Photoelectrochemical Water Splitting
    (IOP, 2022) Sharma, Chhavi; D., Pooja; Thakur, Anupma; Negi, Y. S.; Engineering Technology, Purdue School of Engineering and Technology
    Hydrogen is one of the cleanest, most favourable, and most practical energy transferors. However, its efficient generation, storage and transportation are still a challenge. There are various routes available toward greener hydrogen. Solar-driven splitting is considered a cleaner method with no harmful emission and viability of up-scaling. Various semiconductors were studied for photo-electrochemical catalysis to improve overall efficiency of the system (i.e. Solar-to-Hydrogen (STH)). The insistence of framing this article is to offer an intense evaluation of scientific and technical aspects of available designing strategies' for photocatalysts and recent fruitful advancements towards product development. This review might act as a handbook for budding researchers and provide a cutting-edge towards innovative & efficient catalyst designing strategy to improve efficiency for working scientists.
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    Spherical Templating of CoSe2 Nanoparticle-Decorated MXenes for Lithium-Sulfur Batteries
    (American Chemical Society, 2022) Lieu, Wei Ying; Fang, Daliang; Li, Yuanjian; Li, Xue Liang; Lin, Congjian; Thakur, Anupma; Wyatt, Brian C.; Sun, Shengnan; Ghosh, Tanmay; Anasori, Babak; Ng, Man-Fai; Yang, Hui Ying; Seh, Zhi Wei; Mechanical and Energy Engineering, Purdue School of Engineering and Technology
    Two-dimensional MXenes produce competitive performances when incorporated into lithium–sulfur batteries (LSBs), solving key problems such as the poor electronic conductivity of sulfur and dissolution of its polysulfide intermediates. However, MXene nanosheets are known to easily aggregate and restack during electrode fabrication, filtration, or water removal, limiting their practical applicability. Furthermore, in complex electrocatalytic reactions like the multistep sulfur reduction process in LSBs, MXene alone is insufficient to ensure an optimal reaction pathway. In this work, we demonstrate for the first time a loose templating of sulfur spheres using Ti3C2Tx MXene nanosheets decorated with polymorphic CoSe2 nanoparticles. This work shows that the templating of sulfur spheres using nanoparticle-decorated MXene nanosheets can prevent nanosheet aggregation and exert a strong electrocatalytic effect, thereby enabling improved reaction kinetics and battery performance. The S@MXene-CoSe2 cathode demonstrated a long cycle life of 1000 cycles and a low capacity decay rate of 0.06% per cycle in LSBs.
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    Stabilizing Ti3C2Tx MXene flakes in air by removing confined water
    (National Academy of Sciences, 2024) Fang, Hui; Thakur, Anupma; Zahmatkeshsaredorahi, Amirhossein; Fang, Zhenyao; Rad, Vahid; Shamsabadi, Ahmad A.; Pereyra, Claudia; Soroush, Masoud; Rappe, Andrew M.; Xu, Xiaoji G.; Anasori, Babak; Fakhraai, Zahra; Mechanical and Energy Engineering, Purdue School of Engineering and Technology
    MXenes have demonstrated potential for various applications owing to their tunable surface chemistry and metallic conductivity. However, high temperatures can accelerate MXene film oxidation in air. Understanding the mechanisms of MXene oxidation at elevated temperatures, which is still limited, is critical in improving their thermal stability for high-temperature applications. Here, we demonstrate that Ti[Formula: see text]C[Formula: see text]T[Formula: see text] MXene monoflakes have exceptional thermal stability at temperatures up to 600[Formula: see text]C in air, while multiflakes readily oxidize in air at 300[Formula: see text]C. Density functional theory calculations indicate that confined water between Ti[Formula: see text]C[Formula: see text]T[Formula: see text] flakes has higher removal energy than surface water and can thus persist to higher temperatures, leading to oxidation. We demonstrate that the amount of confined water correlates with the degree of oxidation in stacked flakes. Confined water can be fully removed by vacuum annealing Ti[Formula: see text]C[Formula: see text]T[Formula: see text] films at 600[Formula: see text]C, resulting in substantial stability improvement in multiflake films (can withstand 600[Formula: see text]C in air). These findings provide fundamental insights into the kinetics of confined water and its role in Ti[Formula: see text]C[Formula: see text]T[Formula: see text] oxidation. This work enables the use of stable monoflake MXenes in high-temperature applications and provides guidelines for proper vacuum annealing of multiflake films to enhance their stability.
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    Treatment of carbon electrodes with Ti3C2Tx MXene coating and thermal method for vanadium redox flow batteries: a comparative study
    (Royal Society of Chemistry, 2024-04-19) Teenakul, Kavin; Ahmad Alem, Sayed Ali; Gond, Ritambhara; Thakur, Anupma; Anasori, Babak; Khataee, Amirreza; Mechanical and Energy Engineering, Purdue School of Engineering and Technology
    One of the significant challenges of vanadium redox flow batteries is connected to the negative electrode where the main reaction of V(ii)/V(iii) and the side reaction of hydrogen evolution compete. To address this issue, we used titanium carbide (Ti3C2Tx) MXene coating via drop-casting to introduce oxygen functional groups and metals on the carbon electrode surface. Characterization through scanning electron microscopy and X-ray photoelectron spectroscopy confirmed the even distribution of Ti3C2Tx MXene on the electrodes and the presence of titanium and termination groups (-O, -Cl, and -F). The cyclic voltammetry analysis of MXene-coated electrodes showed more sharp electrochemical peaks for the V(ii)/V(iii) reaction than thermal-treated electrodes, even at relatively high scan rates. Notably, a relatively high reaction rate of 5.61 × 10-4 cm s-1 was achieved for the V(ii)/V(iii) reaction on MXene-coated electrodes, which shows the competitiveness of the method compared to thermal treatment (4.17 × 10-4 cm s-1). The flow battery tests, at a current density of 130 mA cm-2, using MXene-coated electrodes showed pretty stable discharge capacity for over 100 cycles. In addition, the voltage and energy efficiency were significantly higher than those of the system using untreated electrodes. Overall, this work highlights the potential application of MXene coating in carbon electrode treatment for vanadium redox flow batteries due to remarkable electrocatalytic activity and battery performance, providing a competitive method for thermal treatment.