Interactive behavior of graphene quantum dots towards noble metal surfaces

Saeed, Wajeeha; Abbasi, Zeeshan; Bilal, Muhammad; Shah, Sajid Hussain; Waseem, Amir; Shaikh, Ahson Jabbar

doi:10.1016/j.physe.2022.115596

Cited by 13 publications

(3 citation statements)

References 57 publications

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“…The observed color change is likely attributable to alterations in the electronic structure or surface plasmon resonance of the GQDs, resulting in a perceptible transition from blue to green. 59,60 It demonstrated the labeled sensor's selectivity for copper ions. However, the selectivity was also checked in relation to cupric and cuprous ions.…”

Section: Copper Ion Detectionmentioning

confidence: 96%

Hydrothermal Pyrolysis of Styrofoam Waste for Efficient Copper Ion Sensing Using Graphene Quantum Dots

Kumar,

Rani,

Mathew

et al. 2024

ACS Sustainable Resour. Manage.

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The accelerating buildup of plastic waste, especially styrene foam, has become a major environmental problem. Traditional methods of recycling do not help in managing Styrofoam waste efficiently because of economic factors and minimal technological advancements available. Pyrolysis is one of the promising ways to transform styrenofoam wastes into value-added compounds with nominal emission of harmful gases. This research aims to explore the synthesis of graphene quantum dots (GQDs) from Styrofoam waste through hydrothermal pyrolysis and convert it into a high-utility, value-added product. The successful formation of GQDs was confirmed through multiple characterization techniques: transmission electron microscopy revealed a uniform size distribution of 6 ± 1 nm; dynamic light scattering confirmed all GQD samples were below 10 nm; Raman spectroscopy identified the presence of a single-layered graphene structure; and X-ray photoelectron spectroscopy demonstrated the incorporation of nitrogen and oxygen functionalities. The quantum yield of GQDs increased with increase in reaction temperature and the edge functionalities, giving a peak value of 1.87 as confirmed using photoluminescence and UV-Vis spectroscopy, indicating their suitability for enhanced optical performance. The synthesized GQDs were explored as sensors for the detection of heavy metal ions in water. The sensor showed versatility and efficacy for copper ions across different pH levels, water sources, and anions present in various copper salts. Ultimately the concentration of unknown copper ion solutions was calculated from GQD-sensor-based RGB studies, matching closely with UV-Vis spectroscopy values of the unknown solutions. This work demonstrates a promising approach for the pyrolysis-based treatment of plastic waste, contributing to waste management and sustainability efforts.

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Section: Copper Ion Detectionmentioning

confidence: 96%

Hydrothermal Pyrolysis of Styrofoam Waste for Efficient Copper Ion Sensing Using Graphene Quantum Dots

Kumar,

Rani,

Mathew

et al. 2024

ACS Sustainable Resour. Manage.

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“…Among the metallic nanoparticles, silver nanoparticles are very attractive due to their unique properties of nano-sensing [16][17][18][19][20], antibacterial activity [21,22], photocatalytic activity for organic pollutant degradation [23][24][25][26][27], localized surface plasmon resonance (LSPR) [16,17,28,29], and non-linear optical activity [30][31][32]. Moreover, silver as a noble metal is very stable in a water environment compared to other cheaper metals such as copper or iron [33], and it is the less expensive noble metal.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, silver as a noble metal is very stable in a water environment compared to other cheaper metals such as copper or iron [33], and it is the less expensive noble metal. Many syntheses are reported to produce Ag nanoparticles with different sizes and shapes, such as calcination/H 2 reduction [31,34], chemical reduction [16,20,32,[35][36][37], photoreduction [25], bio-based reduction [30,38], pulse laser ablation [39], or biosynthesis [22,[40][41][42]. Nevertheless, the chemical reduction method is one of the most versatile synthesis techniques [43][44][45][46], using a reducing and a capping agent.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Decomposition of H2O2 Using Metallic Silver Nanoparticles under UV/Visible Light for the Removal of p-Nitrophenol from Water

et al. 2023

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Three Ag nanoparticle (NP) colloids are produced from borohydride reduction of silver nitrate in water by varying the amount of sodium citrate. These nanoparticles are used as photocatalysts with H2O2 to degrade a p-nitrophenol (PNP) solution. X-ray diffraction patterns have shown the production of metallic silver nanoparticles, whatever the concentration of citrate. The transmission electron microscope images of these NPs highlighted the evolution from spherical NPs to hexagonal/rod-like NPs with broader distribution when the citrate amount increases. Aggregate size in solution has also shown the same tendency. Indeed, the citrate, which is both a capping and a reducing agent, modifies the resulting shape and size of the Ag NPs. When its concentration is low, the pH is higher, and it stabilizes the formation of uniform spherical Ag NPs. However, when its concentration increases, the pH decreases, and the Ag reduction is less controlled, leading to broader distribution and bigger rod-like Ag NPs. This results in the production of three different samples: one with more uniform spherical 20 nm Ag NPs, one intermediate with 30 nm Ag NPs with spherical and rod-like NPs, and one with 50 nm rod-like Ag NPs with broad distribution. These three Ag NPs mixed with H2O2 in water enhanced the degradation of PNP under UV/visible irradiation. Indeed, metallic Ag NPs produce localized surface plasmon resonance under illumination, which photogenerates electrons and holes able to accelerate the production of hydroxyl radicals when in contact with H2O2. The intermediate morphology sample presents the best activity, doubling the PNP degradation compared to the irradiated experiment with H2O2 alone. This better result can be attributed to the small size of the NPs (30 nm) but also to the presence of more defects in this intermediate structure that allows a longer lifetime of the photogenerated species. Recycling experiments on the best photocatalyst sample showed a constant activity of up to 40 h of illumination for a very low concentration of photocatalyst compared to the literature.

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Engineered hybrid iron‐cobalt metal oxide nanoparticles for effective adsorption of malachite green dye

Hussain,

Shafaat,

Sarfraz

et al. 2024

J of Chemical Tech & Biotech

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BACKGROUNDHybrid iron and cobalt metal oxide nanoparticles are well known; however, are not optimized in terms of size and stability. We engineered these hybrid nanoparticles using the co‐precipitation method and characterized them by various techniques, which are then used for the effective adsorption and removal of malachite green (MG) dye.RESULTSThe ideal conditions for synthesis are determined to be 50:50 ratio of Fe2O3 and CoO, pH of 11, temperature range of 40 °C–60 °C, and reactant addition time of 20 min. These hybrid nanoadsorbents effectively eliminated MG dye from aqueous solutions. Factors such as initial MG dye concentration, pH of the medium, contact time, temperature, and nanoadsorbent dose were optimized for the MG removal to achieve a maximum removal efficiency of 96.9%. Non‐linear fitting of data indicates that both Langmuir and Freundlich models provided the best fit, suggesting the presence of both monolayer and multilayer adsorption of MG on hybrid nanoparticles. The kinetics of MG dye removal are better controlled by the intraparticle diffusion (IPD) phenomenon. The adsorption of MG onto the hybrid nanoparticles was confirmed to be endothermic, with negative ΔG and positive ΔH values. The optimized synthetic conditions also positively impacted the hybrid nanoparticles which enhanced the adsorption and exhibited ferromagnetic behavior as compared to the superparamagnetic behavior reported in the literature, making them significantly important for dye removal applications.CONCLUSIONThese findings demonstrate the potential of optimized hybrid nanoparticles as effective nanoadsorbents for dye removal applications, with implications for further applications in photocatalysis and sensing. © 2024 Society of Chemical Industry (SCI).

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Interactive behavior of graphene quantum dots towards noble metal surfaces

Cited by 13 publications

References 57 publications

Hydrothermal Pyrolysis of Styrofoam Waste for Efficient Copper Ion Sensing Using Graphene Quantum Dots

Hydrothermal Pyrolysis of Styrofoam Waste for Efficient Copper Ion Sensing Using Graphene Quantum Dots

Enhanced Decomposition of H2O2 Using Metallic Silver Nanoparticles under UV/Visible Light for the Removal of p-Nitrophenol from Water

Engineered hybrid iron‐cobalt metal oxide nanoparticles for effective adsorption of malachite green dye

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