Ultra-small (r&lt;2 nm), stable (&gt;1 year) copper oxide quantum dots with wide band gap

Talluri, Bhusankar; Prasad, Edamana; Thomas, Tiju

doi:10.1016/j.spmi.2017.11.044

Cited by 33 publications

(10 citation statements)

References 56 publications

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“…These results are in agreement with those previously reported . It is worth mentioning at this point that the absence of vibrational bands at about 694, 700, 820, and 934 cm –1 , characteristics of Cu 2 O , and Cu(OH) 2 , , evidences the high purity of the CuO NLs. This result is in agreement with the previously discussed XRD results.…”

Section: Resultssupporting

confidence: 93%

Cupric Oxide Nanoleaves for the Oxidative Degradation of Methyl Orange without Heating or Light

Londoño-Calderón

Menchaca-Nal

François

et al. 2020

ACS Appl. Nano Mater.

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Low-cost 2D cupric oxide nanoleaves (CuO NLs) are straightforwardly synthesized at room temperature by precipitation varying the addition method of the alkali. No further treatments are necessary to obtain high purity NLs. The effect of the different addition methods of alkali on the morphological, structural, vibrational, and optical properties is studied by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) and ultraviolet−visible (UV−vis) spectroscopies. NLs grown by alkali addition in a dropwise manner are on average 281, 178, and 17 nm long, wide, and thick, respectively, and composed of crystallites of 14 nm corresponding to the crystallographic planes (1̅ 11)/ ( 002) and ( 111)/(200). NLs obtained by this method agglomerate forming flower-like nanostructures, exhibiting indirect band gap energy of 1.21 eV. NLs grown by alkali addition in a one-step manner are on average significantly bigger, being 602, 219, and 26 nm long, wide, and thick, respectively, composed of crystallites of 19 and 16 nm corresponding to the crystallographic planes (1̅ 11)/(002) and ( 111)/(200), respectively. These NLs agglomerate randomly with no predominant form observed, exhibiting indirect band gap energy of 1.39 eV. The addition method of alkali does not influence the average crystallite size of NLs, whereas the microstrain distribution is sensitive to the initial concentration of OH − ions. Our results suggest that an indirect electronic transition between the valence and conduction bands might be more feasible than a direct one. NLs grown by the one-step method present the highest efficiency as catalyst toward catalytic oxidative degradation of the methyl orange dye with no heating and without the influence of light. Finally, this catalyst is easily recycled several times preserving its high catalytic activity.

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Section: Resultssupporting

confidence: 93%

Cupric Oxide Nanoleaves for the Oxidative Degradation of Methyl Orange without Heating or Light

Londoño-Calderón

Menchaca-Nal

François

et al. 2020

ACS Appl. Nano Mater.

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“…The higher bandgap of the synthesized nanorods compared to bulk CuO is attributed to the quantum size effect. When particle size approaches the nanoscale dimension, the overlapping of adjacent energy levels minimizes and subsequently the width of energy band widens [44]. As the optical properties of the CuO nanorods also indicate the presence of indirect band gap, the Tauc plot derivative for indirect optical bandgap calculation is depicted in Figure 5c.…”

Section: Optical Analysismentioning

confidence: 99%

Muntingia calabura Leaves Mediated Green Synthesis of CuO Nanorods: Exploiting Phytochemicals for Unique Morphology

et al. 2021

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In this study, phytochemical assisted nanoparticle synthesis was performed using Muntingia calabura leaf extracts to produce copper oxide nanoparticles (CuO NPs) with interesting morphology. Scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis of the biosynthesized CuO NPs reveal formation of distinct, homogeneous, and uniform sized CuO nanorods structure with thickness and length of around 23 nm and 79 nm, respectively. Based on Fourier-transform infrared (FTIR) analysis, the unique combinations of secondary metabolites such as flavonoid and polyphenols in the plant extract are deduced to be effective capping agents to produce nanoparticles with unique morphologies similar to conventional chemical synthesis. X-ray diffraction (XRD) analysis verified the monoclinical, crystalline structure of the CuO NPs. The phase purity and chemical identity of the product was consolidated via X-Ray photoelectron spectroscopy (XPS) and Raman spectroscopic data which indicate the formation of a single phase CuO without the presence of other impurities. The direct and indirect optical band gap energies of the CuO nanorods were recorded to be 3.65 eV and 1.42 eV.

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“…Particularly, the decrease in particle size, as well as the increase in band gap energy of the as-prepared nanoparticles, signified the size quantization effects [16]. When particle size reached the nanosized scale, the overlapping of adjacent energy levels minimized and, subsequently, the width of energy band widened [17,18]. that this could be due to the more viscous nature of the aloe vera extract, which adheres to the surface of the nanoparticles during synthesis.…”

Section: Optical Propertiesmentioning

confidence: 99%

Phytochemical-Assisted Green Synthesis of Nickel Oxide Nanoparticles for Application as Electrocatalysts in Oxygen Evolution Reaction

et al. 2021

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Electrocatalytic water splitting is a promising solution to resolve the global energy crisis. Tuning the morphology and particle size is a crucial aspect in designing a highly efficient nanomaterials-based electrocatalyst for water splitting. Herein, green synthesis of nickel oxide nanoparticles using phytochemicals from three different sources was employed to synthesize nickel oxide nanoparticles (NiOx NPs). Nickel (II) acetate tetrahydrate was reacted in presence of aloe vera leaves extract, papaya peel extract and dragon fruit peel extract, respectively, and the physicochemical properties of the biosynthesized NPs were compared to sodium hydroxide (NaOH)-mediated NiOx. Based on the average particle size calculation from Scherrer’s equation, using X-ray diffractograms and field-emission scanning electron microscope analysis revealed that all three biosynthesized NiOx NPs have smaller particle size than that synthesized using the base. Aloe-vera-mediated NiOx NPs exhibited the best electrocatalytic performance with an overpotential of 413 mV at 10 mA cm−2 and a Tafel slope of 95 mV dec−1. Electrochemical surface area (ECSA) measurement and electrochemical impedance spectroscopic analysis verified that the high surface area, efficient charge-transfer kinetics and higher conductivity of aloe-vera-mediated NiOx NPs contribute to its low overpotential values.

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Ultra-small (r<2 nm), stable (>1 year) copper oxide quantum dots with wide band gap

Cited by 33 publications

References 56 publications

Cupric Oxide Nanoleaves for the Oxidative Degradation of Methyl Orange without Heating or Light

Cupric Oxide Nanoleaves for the Oxidative Degradation of Methyl Orange without Heating or Light

Muntingia calabura Leaves Mediated Green Synthesis of CuO Nanorods: Exploiting Phytochemicals for Unique Morphology

Phytochemical-Assisted Green Synthesis of Nickel Oxide Nanoparticles for Application as Electrocatalysts in Oxygen Evolution Reaction

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