An investigation on the tuning effect of glucose-capping on the size and bandgap of CuO nanoparticles

Jeyarani, W. Jothi; Tenkyong, Tenzin; Bachan, Neena; Kumar, D. Arun; Shyla, J. Merline

doi:10.1016/j.apt.2016.01.006

Cited by 36 publications

(8 citation statements)

References 44 publications

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“…Although CuO x -0.025M/15m incorporates some Cu 2 O, which has a larger band gap range of 1.8–2.5 eV, the calculated band gap is slightly smaller than the control, at 1.28 eV. This is attributed to the competing impact of the increase in size and the presence of oxygen vacancies, both factors that will decrease the optical band gap. , As the particles are treated with higher NaBH 4 concentrations, there is a continual gradual decrease in band gap. This is not surprising as the NaBH 4 treatment is shown to propel the formation of Cu(0), which, it should be noted, impedes an accurate determination of the band gap from the Tauc plot.…”

Section: Resultsmentioning

confidence: 86%

“…As the CuO particles are subjected to post-treatments, their measured band gaps shift. Changes in the band gap are related to the metal oxidation state, as well as the particle size, shape, crystallinity, microstrain, and oxygen vacancies . Although CuO x -0.025M/15m incorporates some Cu 2 O, which has a larger band gap range of 1.8–2.5 eV, the calculated band gap is slightly smaller than the control, at 1.28 eV.…”

Section: Resultsmentioning

confidence: 92%

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Multivariate Analysis on the Structure–Activity Parameters for Nano-CuO_x-Catalyzed Reduction Reactions

Shultz-Johnson,

Chang,

Bisram

et al. 2024

ACS Appl. Nano Mater.

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Understanding the origin of enhanced catalytic activity is critical to heterogeneous catalyst design. This is especially important for non-noble metalbased catalysts, notably metal oxides, which have recently emerged as viable candidates for numerous thermal catalytic processes. For thermal catalytic reduction/hydrogenation using metal oxide nanoparticles, enhanced catalytic performance is typically attributed to an increased surface area and the presence of oxygen vacancies. Concomitantly, the treatments that induce oxygen vacancies also impact other material properties, such as the microstrain, crystallinity, oxidation state, and particle shape. Herein, multivariate statistical analysis is used to disentangle the impact of material properties of CuO nanoparticles on catalytic rates for nitroaromatic and methylene blue reduction. The impact of the microstrain, shape, and Cu(0) atomic percent is demonstrated for these reactions; furthermore, a protocol for correlating material property parameters to catalytic efficiency is presented, and the importance of catalyst design for these broadly utilized probe reactions is highlighted.

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Section: Resultsmentioning

confidence: 86%

Section: Resultsmentioning

confidence: 92%

Multivariate Analysis on the Structure–Activity Parameters for Nano-CuO_x-Catalyzed Reduction Reactions

Shultz-Johnson,

Chang,

Bisram

et al. 2024

ACS Appl. Nano Mater.

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“…The hierarchical Cu-CNT NW structure exhibits an extremely low average total reflectance of 0.75 ± 0.26% in the vis-to-NIR range and 1.37 ± 0.92% in the MIR range, clearly outperforming the other studied structures as well as previously reported hierarchical, carbon-based systems. − Comparing the featureless spectrum of the CuO film with that of the CuO NW structure, we observe that the light trapping effect of the microscale NWs , reduces the average total reflectance from a few percent to less than 1% in the 400–700 nm range. However, beyond 700 nm, the reflectance increases significantly because of the limited light absorption below the bandgap of CuO (1.4–1.7 eV). , Similarly, for the forest of Cu NWs, light-trapping by the nanowire geometry minimizes the reflection at short wavelengths, where the metal has stronger absorption due to interband transitions . By comparing the response of Cu NW arrays with that of the cactus-like Cu-CNT structure, we observe that the CNT deposition dramatically suppresses the reflectance of the Cu NWs for wavelengths longer than 550 nm.…”

Section: Resultsmentioning

confidence: 88%

“…However, beyond 700 nm, the reflectance increases significantly because of the limited light absorption below the bandgap of CuO (1.4−1.7 eV). 61,62 Similarly, for the forest of Cu NWs, lighttrapping by the nanowire geometry minimizes the reflection at short wavelengths, where the metal has stronger absorption due to interband transitions. 63 By comparing the response of Cu NW arrays with that of the cactus-like Cu-CNT structure, we observe that the CNT deposition dramatically suppresses the reflectance of the Cu NWs for wavelengths longer than 550 nm.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Ultra-Broadband and Omnidirectional Perfect Absorber Based on Copper Nanowire/Carbon Nanotube Hierarchical Structure

et al. 2020

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Zero reflection and complete light absorption are required in a wide range of applications ranging from sensing devices to solar heaters and photoelectrodes. However, simultaneously satisfying the requirements of the broadband spectrum, omnidirectionality, polarization insensitivity, and scalability is very challenging. Combining the light-trapping characteristics of microscale copper nanowires (Cu NWs) with the unique optical properties of carbon nanotubes (CNTs), we experimentally demonstrate a novel perfect absorber that has an average total reflectance of 0.75% over the broad 400–1000 nm wavelength range and an average specular reflectance as low as 0.1%. Importantly, our cactus-like, hierarchical structure retains a similar performance independently of light polarization and for a broad range of incident angles. We furthermore developed a model that elucidates how the Cu NW and CNT components synergistically contribute to the suppression of both specular and diffuse reflections while maximizing light absorption. Thanks to the scalability of the fabrication process, on the basis of the thermal oxidation and chemical vapor deposition methods, our broadband and omnidirectional perfect absorber exhibits a large potential for boosting the performance of many light-harnessing devices.

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“…The reduction of the particle size of Mn 3 O 4 can be achieved using CAs during synthesis. Organic molecules containing OH groups, such as glucose, salicylates, and molecules from the chromotropic acid family, show adsorption on inorganic particles and generate interest for application as CAs and dispersing agents. − Tetrahydroxy-1,4-quinone (TQ), catechin (CT), and gallocyanine (GC) are promising materials for CA application. They belong to the catechol family of materials (Figure A–C), which show strong adsorption on particles by bonding to surface atoms (Figure D).…”

Section: Introductionmentioning

confidence: 99%

Influence of Capping Agents on the Synthesis of Mn₃O₄ Nanostructures for Supercapacitors

Yang

Zhitomirsky

2023

ACS Appl. Nano Mater.

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Nanotechnology offers powerful strategies for the synthesis of advanced materials for supercapacitors. It is hypothesized that the size reduction of Mn3O4 nanoparticles can eliminate time-consuming electrochemical activation and increase the electrochemical pseudocapacitance of this material. Moreover, due to the redox properties and specific features of its chemical synthesis procedure, Mn3O4 can potentially outperform other promising cathode materials for energy storage in supercapacitors. A facile room temperature method to fabricate Mn3O4 nanoparticles is described, which is based on the application of advanced capping agents (CAs) for nanofabrication. Building on the strong adsorption power of the catechol ligand, we utilize tetrahydroxy-1,4-quinone, catechin, and gallocyanine as CAs for the preparation of Mn3O4. The use of the catecholate molecules as CAs for chemical precipitation facilitates the preparation of Mn3O4 platelet nanoparticles with a typical size of 5 nm. The reduction of the particle size allows the fabrication of advanced Mn3O4 multiwalled carbon nanotube cathodes with 40 mg cm–2 active mass (AM), which show a significant increase in capacitance in a 0.5 M Na2SO4 electrolyte. The highest capacitances of 7.03 F cm–2 (175.8 F g–1) at a potentiodynamic sweep rate of 2 mV s–1 and 9.13 F cm–2 (228.3 F g–1) at a constant current density of 3 mA cm–2 are obtained at a low impedance using gallocyanine as a CA. Obtained electrodes outperform MnO2-based cathodes of similar mass. Another important finding is the possibility to avoid the time-consuming activation process for Mn3O4-based electrodes. Analysis of the testing results provides evidence of the influence of the CA structure on the electrode performance. The results of this investigation pave the way for the application of Mn3O4 in advanced high-AM supercapacitor cathodes.

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An investigation on the tuning effect of glucose-capping on the size and bandgap of CuO nanoparticles

Cited by 36 publications

References 44 publications

Multivariate Analysis on the Structure–Activity Parameters for Nano-CuO_x-Catalyzed Reduction Reactions

Multivariate Analysis on the Structure–Activity Parameters for Nano-CuO_x-Catalyzed Reduction Reactions

Ultra-Broadband and Omnidirectional Perfect Absorber Based on Copper Nanowire/Carbon Nanotube Hierarchical Structure

Influence of Capping Agents on the Synthesis of Mn₃O₄ Nanostructures for Supercapacitors

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An investigation on the tuning effect of glucose-capping on the size and bandgap of CuO nanoparticles

Cited by 36 publications

References 44 publications

Multivariate Analysis on the Structure–Activity Parameters for Nano-CuOx-Catalyzed Reduction Reactions

Multivariate Analysis on the Structure–Activity Parameters for Nano-CuOx-Catalyzed Reduction Reactions

Ultra-Broadband and Omnidirectional Perfect Absorber Based on Copper Nanowire/Carbon Nanotube Hierarchical Structure

Influence of Capping Agents on the Synthesis of Mn3O4 Nanostructures for Supercapacitors

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Multivariate Analysis on the Structure–Activity Parameters for Nano-CuO_x-Catalyzed Reduction Reactions

Multivariate Analysis on the Structure–Activity Parameters for Nano-CuO_x-Catalyzed Reduction Reactions

Influence of Capping Agents on the Synthesis of Mn₃O₄ Nanostructures for Supercapacitors