Microwave treated sol–gel synthesis and characterization of hybrid ZnS–RGO composites for efficient photodegradation of dyes

Lellala, Kashinath; Namratha, K.; Srikantaswamy, S.; Vinu, Ajayan; Byrappa, K.

doi:10.1039/c6nj03716j

Cited by 52 publications

(18 citation statements)

References 64 publications

(67 reference statements)

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“…This may be attributed to the shielding effect of ZnS that caused the RGO surface to be densely covered by the ZnS component, leading to diminishing the scattering effect of RGO. Another explanation is that the interfacial interaction between ZnS and RGO might also contribute to the noticeable change of absorbance between TQZR-3 and TQRZ-3. , Apparently, there is a strong dependence between the photovoltaic performance and the deposition sequences of RGO. The J – V curves and detailed corresponding average photovoltaic parameters of the solar cells with different sequences of RGO deposition are shown in Figure S2 and Table S2, respectively.…”

Section: Resultsmentioning

confidence: 99%

Impacts of Reduced Graphene Oxide in CdS/CdSe Quantum Dots Co-sensitized Solar Cells

Wu¹,

Zhao²,

Huang

et al. 2017

J. Phys. Chem. C

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The introduction of various amounts of reduced graphene oxide (RGO) to CdS/CdSe quantum dots co-sensitized solar cells was investigated to enhance the light absorption and to promote the electron transfer. The characterization and comparison of optical and electrochemical properties as well as the performance of the resultant quantum dot-sensitized solar cells (QDSCs) with different amounts of RGO have been investigated systematically. The introduction of RGO demonstrated to enhance the light harvesting and consequently increase the short-circuit current density (J sc). ZnS inserting between QDs and RGO can effectively block the charge recombination at the interface; however, the defects of RGO in the TiO2/QDs/ZnS/RGO photoanode still may accelerate the interface charge recombination in QDSCs and lead to a slight decrease of the open-circuit voltage (V oc). The balance between the light harvesting and charge recombination in RGO modified QDSCs is a key for achieving high power conversion efficiency (PCE). Finally, the CdS/CdSe/ZnS co-sensitized cell with modification RGO (3 min) achieved a high PCE of 5.28% (J sc = 15.8 mA/cm2, V oc = 572 mV), more than 13% higher than that of 4.69% (J sc = 13.7 mA/cm2, V oc = 602 mV) obtained for the cell without RGO.

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Section: Resultsmentioning

confidence: 99%

Impacts of Reduced Graphene Oxide in CdS/CdSe Quantum Dots Co-sensitized Solar Cells

Wu¹,

Zhao²,

Huang

et al. 2017

J. Phys. Chem. C

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“…The inset displays Tauc plots that is the relation of [αhν] 1/2 versus photonic energy, which indicates the bandgap of ZnS QDs and composites are 3.32 and 3.36 eV, respectively. The slight change in band gap is probably attributed to the variation of ZnS QDs particle size with quantum size effect and the interfacial action of surface plasmons of rGO and ZnS QDs . These phenomenon also shows the close connection between the interfaces of ZnS QDs and rGO.…”

Section: Resultsmentioning

confidence: 86%

One‐Step Hydrothermal Synthesis of ZnS Quantum Dots‐Reduced Graphene Oxide Composites with Enhanced Photocatalytic Activity

Wei

Hong

Han

et al. 2018

Physica Status Solidi (a)

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Zinc sulfur quantum dots-reduced graphene oxide (ZnS QDs-rGO) composites are successfully synthesized by a one-step hydrothermal method. The ZnS QDs are well scattered on the surface of the wrinkled rGO with smaller particle size compared with initial ZnS QDs. The influence of the content of rGO in composites on the photocatalytic effect is also investigated in detail. The ZnS QDs-1.0% rGO has the highest photocatalytic activity and the degradation kinetics of methylene blue is more consistent with the zero order kinetic model than the pseudo first order kinetic model in this experiment. The mechanism for the enhancement of photocatalytic activity is mainly due to promoting separation of the photogenerated carriers with the introduction of rGO and the increase in specific surface area of ZnS QDs due to decrease in size. These results reveal that the effective synergistic action between ZnS QDs and rGO is the key factor to determine the photocatalytic degradation efficiency of the ZnS QDs-rGO composites.

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“…The filtered solution was treated with microwave irradiation for 5 min at 900 W and kept for hydrothermal treatment (stainless steel autoclaves) processing at 150 °C for 24 h. The products obtained were washed with water followed by a centrifuging process, and the resultant product was dried in a vacuum oven for 24 h at 80 °C to give a black solid particle named graphene oxide (GO). 39,40 2.3. Synthesis of Hybrid Nanocomposite Fe 3 O 4 −GO.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Later, dilute hydrochloric acid solution (10 mL of HCl and 200 mL of water) was used for the washing and filtering of the solution several times. The filtered solution was treated with microwave irradiation for 5 min at 900 W and kept for hydrothermal treatment (stainless steel autoclaves) processing at 150 °C for 24 h. The products obtained were washed with water followed by a centrifuging process, and the resultant product was dried in a vacuum oven for 24 h at 80 °C to give a black solid particle named graphene oxide (GO). , …”

Section: Experimental Methodsmentioning

confidence: 99%

Microwave-Assisted Facile Hydrothermal Synthesis of Fe₃O₄–GO Nanocomposites for the Efficient Bifunctional Electrocatalytic Activity of OER/ORR

Lellala

2021

Energy Fuels

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A challenging task is to develop and improve the efficiency of the electrocatalysts for bifunctional oxygen reaction activities for the higher generation of current with lower overpotential. In the present work, ultrafine Fe 3 O 4 nanoparticles were uniformly decorated on the layered surface of graphene oxide (GO) sheets using the microwave-assisted hydrothermal method and successfully tested for bifunctional oxygen reaction activities for the first time. This heterostructure composites were used as a promising candidate for highly efficient bifunctional material for oxygen evolution/reduction reactions (ORR/OER) in both KOH and H 2 SO 4 solutions. The composite structure and morphology were characterized by scanning and high-resolution transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and Xray photoelectron spectroscopy. These heterostructure composites show a very low onset potential value for ORR (0.975 V vs RHE) and OER (1.25 V vs RHE) in the presence of KOH solution. Additionally, the composites exhibit superior performance activity for ORR (0.92 V vs RHE) and OER (1.2 V vs RHE) in sulfuric acid solution. Interestingly, the pure GO showed a better result than the previously reported work that supported the superior electrocatalytic performance of the hybrid composites. This coupling of techniques provides a higher density of Fe−C−O crystalline sites and ultrafine Fe−O particles as boosting higher charge transferability in the composites. This physicochemical behavior facilitates in breaking the functional groups on the surface and providing more active transfer sites that are influenced by microwave and hydrothermal processing. This study may provide useful insights into the Fe-enabled high bifunctional activity to guide the design of an efficient catalyst for many potential electrochemical activities.

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Microwave treated sol–gel synthesis and characterization of hybrid ZnS–RGO composites for efficient photodegradation of dyes

Abstract: Excellent photocatalytic activity by highly photo-responsive electron transfer from ZnS–RGO, and RGO acts as an electron reservoir and effectively suppresses charge recombination.

Cited by 52 publications

References 64 publications

Impacts of Reduced Graphene Oxide in CdS/CdSe Quantum Dots Co-sensitized Solar Cells

Impacts of Reduced Graphene Oxide in CdS/CdSe Quantum Dots Co-sensitized Solar Cells

One‐Step Hydrothermal Synthesis of ZnS Quantum Dots‐Reduced Graphene Oxide Composites with Enhanced Photocatalytic Activity

Microwave-Assisted Facile Hydrothermal Synthesis of Fe₃O₄–GO Nanocomposites for the Efficient Bifunctional Electrocatalytic Activity of OER/ORR

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Microwave treated sol–gel synthesis and characterization of hybrid ZnS–RGO composites for efficient photodegradation of dyes

Abstract: Excellent photocatalytic activity by highly photo-responsive electron transfer from ZnS–RGO, and RGO acts as an electron reservoir and effectively suppresses charge recombination.

Cited by 52 publications

References 64 publications

Impacts of Reduced Graphene Oxide in CdS/CdSe Quantum Dots Co-sensitized Solar Cells

Impacts of Reduced Graphene Oxide in CdS/CdSe Quantum Dots Co-sensitized Solar Cells

One‐Step Hydrothermal Synthesis of ZnS Quantum Dots‐Reduced Graphene Oxide Composites with Enhanced Photocatalytic Activity

Microwave-Assisted Facile Hydrothermal Synthesis of Fe3O4–GO Nanocomposites for the Efficient Bifunctional Electrocatalytic Activity of OER/ORR

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Microwave-Assisted Facile Hydrothermal Synthesis of Fe₃O₄–GO Nanocomposites for the Efficient Bifunctional Electrocatalytic Activity of OER/ORR