Uranium Phthalocyanine-Anchored Acid-Functionalized Multiwalled Carbon Nanotubes for Water Electrolysis

Giddaerappa,; Puttaningaiah, Keshavananda Prabhu Channabasavana Hundi; Aralekallu, Shambhulinga; Shantharaja,; Naseem Kousar,; Chikkabasur Kumbara, Ashwini; Sannegowda, Lokesh Koodlur

doi:10.1021/acsanm.3c01328

Cited by 16 publications

(5 citation statements)

References 60 publications

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“…Two superimposable peaks at 400.2 and 402.1 eV, which correspond to the –C–NH 2 bond and nitrogen coordinated with carbon and cobalt metal, respectively, were visible in the N 1s XPS spectrum (Figure c) . A prominent peak at 533.4 eV was identified in the O 1s spectrum (Figure d) for being associated with the C–O–C bond . Furthermore, four peaks appeared in the deconvoluted cobalt spectrum (Figure e), with Co 2p 3/2 and its satellite peak at 782.8 and 787.15 eV and Co 2p 1/2 and its satellite peak at 798.1 and 804.14 eV, respectively, indicating the presence of cobalt in the +2 oxidation state with high spin in the hybrid catalyst and confirming the coordination between cobalt and nitrogen atoms …”

Section: Resultsmentioning

confidence: 94%

“…The vibronic fine structure of poly[Co (II) THTPc] and the existence of dimeric/oligomeric species in the polymer were indicated by a small shoulder peak at 602 nm . Furthermore, the hybrid composite exhibited a bathochromic shift with reduced peak intensity compared to poly[Co (II) THTPc] due to increased π–π interactions with KB nanoparticles . Thermal analysis of poly[Co (II) THTPc] was performed using thermogravimetric analysis, as shown in Figure S3, which disclosed three distinct weight-loss stages involving dehydration (<105 °C), degradation of amine and catechol moieties (250–300 °C), and decomposition of the Pc core ring (610–740 °C), leading to stable CoO formation (>740 °C).…”

Section: Resultsmentioning

confidence: 99%

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Phthalocyanine Polymer Anchored Ketjen Black Nanoparticles for Bifunctional Oxygen Electrocatalysis

Kousar,

Thimmappa,

Giddaerappa

et al. 2024

ACS Appl. Nano Mater.

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The limitations of current benchmark oxygen electrocatalysts, such as RuO 2 , IrO 2 , and Pt/C, due to their high cost, scarcity, and unifunctionality, have inspired a search for more effective oxygen catalysts to advance sustainable enegry solutions. Hence, development of cost-effective bifunctional catalysts to overcome the issues associated with benchmark catalysts is crucial. Metal−organic framework composites containing conductive carbon materials present promising solutions to these challenges. This study reports the synthesis, characterization, and application of a metal−organic framework of cobalt(II) tetra(3-hydroxy tyramine) phthalocyanine polymer, poly[Co (II) THTPc], for bifunctional oxygen electrocatalysis. The synthesis methodology is simple, cost-effective, and sustainable. To improve the catalytic performance of poly[Co (II) THTPc], an organic-hybrid composite was prepared by incorporating Ketjen black (KB) nanoparticles at an optimized ratio. The resulting poly[Co (II) THTPc]:KB (4:1, respectively) hybrid exhibited outstanding catalytic activity for OER bearing an overpotential of 359 mV on a Ni foam substrate and 371 mV on a glassy carbon electrode (GCE) substrate at 10 mA cm −2 current density in 1.0 M KOH at 5 mV s −1 scan rate. Furthermore, the same composite catalyst demonstrated an onset potential of 0.876 V vs RHE for ORR with a half-wave potential of 0.767 V vs RHE, obeying four-electrontransfer pathway in the same electrolyte and scan rate on GCE. In addition, the designed hybrid catalyst demonstrated improved catalytic properties compared to standard catalysts, including a lower Tafel slope, reduced charge-transfer resistance, and higher exchange current density for OER and ORR. The remarkable catalytic performance of the developed hybrid can be attributed to various synergistic effects, favorable π−π interactions, and increased number of electroactive sites that downshifts the D-band center of Co adsorption sites, effectively reducing the activation barrier of reaction intermediates in both the OER and ORR. Importantly, the low-cost bifunctional oxygen catalyst exhibited excellent stability and efficiency, making it a potential bifunctional oxygen electrocatalyst for large-scale integrated green energy systems.

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 99%

Phthalocyanine Polymer Anchored Ketjen Black Nanoparticles for Bifunctional Oxygen Electrocatalysis

Kousar,

Thimmappa,

Giddaerappa

et al. 2024

ACS Appl. Nano Mater.

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“…The Nyquist plots with their equivalent circuits (inset) for HER and OER are represented in Figure a,b. The elements of the equivalent circuit such as R s , R ct , R c , C , and Q indicate the solution resistance, charge-transfer resistance, coating resistance, capacitance, and constant phase element, respectively. , All of the electrodes exhibited different kinetics with a difference in R ct values and are summarized in Tables S3 and S4. For both HER and OER, the composite electrode (HQCoPc + KB) displayed a lower resistance ( R ct ) value compared to other electrodes, which implies better charge transfer and kinetics at the electrode/electrolyte interface of the HQCoPc + KB electrode.…”

Section: Resultsmentioning

confidence: 99%

Cobalt Phthalocyanine Based Metal–Organic Framework as an Efficient Bifunctional Electrocatalyst for Water Electrolysis

Giddaerappa,

Naseem Kousar,

Deshpande

et al. 2024

Energy Fuels

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Water is the most convenient and facile fossil-free source for the production of hydrogen (H 2 ). Electrochemical water splitting is considered a promising and potential approach for accomplishing hydrogen frugality. Although water-splitting reaction is the most versatile and green technique, it accounts for only 4% of the universal H 2 production. The main hindrance in large-scale production is the sluggish kinetics of the reaction, which employs costlier and precious catalysts. In addition, the half-cell reactions for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting require two different types of precious catalysts, which not only increases the cost but also decreases the efficiency due to the enhanced complexity of the system. Hence, designing an efficient, robust, nonprecious, earthabundant, and low-cost electrocatalyst capable of catalyzing both HER and OER during overall water splitting is an urgent requirement to meet the energy demand for sustainable growth. Here, a highly potential bifunctional electrocatalyst is fabricated using quinone-substituted cobalt(II) phthalocyanine (HQCoPc) with carbon nanoparticles (Ketjen black, KB). The organic hybrid of HQCoPc + KB modified on GCE and Ni foam showed remarkable electrocatalytic performance for HER and OER in acidic and basic conditions, respectively. The HQCoPc + KB composite affords a lower onset of 76 mV for HER and an overpotential of 234 and 360 mV at 10 mA•cm −2 for HER and OER, respectively, with superior stability for more than 40,000 s. The designed HQCoPc + KB bifunctional electrocatalyst not only offers a better catalyst for addressing a water-splitting reaction but also provides costeffectiveness and good chemical stability for sustainable energy technology.

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“…Carbon nanomaterials (graphene, carbon nanotubes, graphene oxide, etc.) contribute to enhanced electrical conductivity and a large surface area, while macrocycles provide tenable biocompatibility, enhanced sensor responsiveness, and processability [ 39 , 65 ]. Furthermore, the inclusion of metal nanoparticles enhances the sensing capability of nanohybrid materials by adding significant catalytic activity, signal amplification, and distinctive optical properties [ 66 ].…”

Section: Introductionmentioning

confidence: 99%

Macromolecule–Nanoparticle-Based Hybrid Materials for Biosensor Applications

Kuntoji,

Kousar,

Gaddimath

et al. 2024

Biosensors

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Biosensors function as sophisticated devices, converting biochemical reactions into electrical signals. Contemporary emphasis on developing biosensor devices with refined sensitivity and selectivity is critical due to their extensive functional capabilities. However, a significant challenge lies in the binding affinity of biosensors to biomolecules, requiring adept conversion and amplification of interactions into various signal modalities like electrical, optical, gravimetric, and electrochemical outputs. Overcoming challenges associated with sensitivity, detection limits, response time, reproducibility, and stability is essential for efficient biosensor creation. The central aspect of the fabrication of any biosensor is focused towards forming an effective interface between the analyte electrode which significantly influences the overall biosensor quality. Polymers and macromolecular systems are favored for their distinct properties and versatile applications. Enhancing the properties and conductivity of these systems can be achieved through incorporating nanoparticles or carbonaceous moieties. Hybrid composite materials, possessing a unique combination of attributes like advanced sensitivity, selectivity, thermal stability, mechanical flexibility, biocompatibility, and tunable electrical properties, emerge as promising candidates for biosensor applications. In addition, this approach enhances the electrochemical response, signal amplification, and stability of fabricated biosensors, contributing to their effectiveness. This review predominantly explores recent advancements in utilizing macrocyclic and macromolecular conjugated systems, such as phthalocyanines, porphyrins, polymers, etc. and their hybrids, with a specific focus on signal amplification in biosensors. It comprehensively covers synthetic strategies, properties, working mechanisms, and the potential of these systems for detecting biomolecules like glucose, hydrogen peroxide, uric acid, ascorbic acid, dopamine, cholesterol, amino acids, and cancer cells. Furthermore, this review delves into the progress made, elucidating the mechanisms responsible for signal amplification. The Conclusion addresses the challenges and future directions of macromolecule-based hybrids in biosensor applications, providing a concise overview of this evolving field. The narrative emphasizes the importance of biosensor technology advancement, illustrating the role of smart design and material enhancement in improving performance across various domains.

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Uranium Phthalocyanine-Anchored Acid-Functionalized Multiwalled Carbon Nanotubes for Water Electrolysis

Cited by 16 publications

References 60 publications

Phthalocyanine Polymer Anchored Ketjen Black Nanoparticles for Bifunctional Oxygen Electrocatalysis

Phthalocyanine Polymer Anchored Ketjen Black Nanoparticles for Bifunctional Oxygen Electrocatalysis

Cobalt Phthalocyanine Based Metal–Organic Framework as an Efficient Bifunctional Electrocatalyst for Water Electrolysis

Macromolecule–Nanoparticle-Based Hybrid Materials for Biosensor Applications

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