High-efficient Synthesis of Graphene Oxide Based on Improved Hummers Method

Yu, Hang; Zhang, Bangwen; Bulin, Chaoke; Li, Ruihong; Xing, Ruiguang

doi:10.1038/srep36143

Cited by 543 publications

(289 citation statements)

References 34 publications

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“…It also causes an increase in electrocatalytic activity of graphene because of the increase in spin densities and asymmetries of charge at the various sites of the double‐doped graphene. A power conversion efficiency of 8.08% which is superior to 6.34% of Pt‐CE was achieved when GO was reduced and doped with nitrogen and boron . This B and N co‐doped graphene was reported by Yu et al where the doped graphene was achieved via chemically grafting ionic liquid followed by thermal annealing.…”

Section: Dsscsmentioning

confidence: 73%

“…It involves the oxidation of graphite via different chemical routes such as Brodie's oxidation method (fuming nitric acid and potassium chlorate), Staudenmaier method (fuming HNO 3 , concentrated H 2 SO 4 , and KClO 4 ), Hofmann method (concentrated HNO 3 , concentrated H 2 SO 4 , and KClO 4 ), and Hummers method (concentrated H 2 SO 4 in the presence of KMnO 4 ) . Hummers method has been reported to be the best and simplest method to yield good quality GO …”

Section: Heteroatom‐doped Graphenementioning

confidence: 99%

“…164 Hummers method has been reported to be the best and simplest method to yield good quality GO. [165][166][167] Graphene oxide acts as an electrically insulating material because of the structural disorder applied by the C-O bonds (sp 3 ) which disrupts its conductive πnetwork. 168 The disruption in electrical conductivity can be restored by reduction of GO.…”

Section: Oxygen-doped Graphenementioning

confidence: 99%

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Heteroatom-doped graphene and its application as a counter electrode in dye-sensitized solar cells

2018

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Summary The most frequently used counter electrode (CE) in dye‐sensitized solar cells (DSSCs) is platinum on fluorine‐doped tin oxide glass. This electrode has excellent electrical conductivity, chemical stability, and high electrocatalytic affinity for the reduction of triiodide. However, the high cost of metallic platinum and the poor electrochemical stability pose a major drawback in the commercial production. This has necessitated a search for a non‐precious metal and metal‐free electrocatalyst that demonstrates better catalytic activity and longer electrochemical stability for practical use in DSSCs. Graphene has been at the centre of attention due to its excellent optoelectronic properties. However, a defect‐free graphene sheet is not suitable as a CE in DSSCs, because of its neutral polarity which often restricts efficient charge transfer at the graphene/liquid interface, irrespective of the high in‐plane charge mobility. Hence, heteroatom‐doped graphene‐based CEs are being developed with the aim to balance electrical conductivity for efficient charge transfer and charge polarization for enhanced reduction activity of redox couples simultaneously. The elements commonly used in chemical doping of graphene are nitrogen, oxygen, boron, sulfur, and phosphorus. Halogens have also recently shown great promise. It has been demonstrated that edge‐selective heteroatom‐doping of graphene imparts both efficient in‐plane charge transfers and polarity, thereby enhancing electrocatalytic activity. Thus, heteroatom‐doped graphene serves as a good material to replace conventional electrodes and enhance power conversion efficiency in DSSCs. The focus is to reduce the cost of DSSCs. This review explores the performance of DSSCs, factors that influence the power conversion efficiency, and various physicochemical properties of graphene. It further outlines current progress on the synthetic approaches for chemical doping (substitutional and surface transfer doping) of graphene and graphene oxide with different heteroatoms in order to fine‐tune the electronic properties. The use of heteroatom‐doped graphene as a CE in DSSCs and how it improves the photovoltaic performance of cells is discussed.

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Section: Dsscsmentioning

confidence: 73%

Section: Heteroatom‐doped Graphenementioning

confidence: 99%

Section: Oxygen-doped Graphenementioning

confidence: 99%

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Heteroatom-doped graphene and its application as a counter electrode in dye-sensitized solar cells

2018

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“…The GO suspension was obtained by graphite oxidation by a modified Hummers method [4][5][6]. To this end, a solution was prepared from 0.1 g of graphite powder, 0.05 g of sodium nitrate and concentrated sulfuric acid of 7 ml with the addition of 0.3 g of potassium permanganate.…”

Section: Methodsmentioning

confidence: 99%

Use of Nanocomposite Material Based on Graphene Oxide and Silver Nanoparticles in Research of Blood Erythrocytes in Various Diseases

Mamaeva¹,

Максимов²,

Neustroev³

et al. 2018

KEn

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The electrical and structural properties of a nanocomposite material based on silver nanoparticles and graphene oxide were investigated. Using electron and atomic force microscopy it was shown that the nanoparticles formed predominantly have sizes from 60 to 100 nm. Measurements of the current-voltage characteristics showed electrical conductivity values significantly exceeding the parameters of the initial graphene oxide. The prepared nanocomposites were used for scanning by electron microscopy (SEM) of blood samples of sick children with hematuria syndrome and patients of the radiological department of an oncologic dispensary diagnosed with cervical cancer. The formation of nanosize objects on the surface of erythrocytes is revealed. The size of these volumes is comparable to the size of the viruses. Results of these studies can indirectly confirm an assumption of authors about possible transportation of viruses by erythrocytes to various organs and viral etiology of renal diseases with the hematuria syndrome and cervical cancer.

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“…For production of graphene, several procedures have been used to carry out the exfoliation of the π-stacked carbon layers such as the chemical vapor deposition and the micromechanical cleavage of graphite [113,114]. A common procedure used due to its simplicity and low cost is the Hummers method, which consists of the strong oxidation of the bulk graphite, its exfoliation and the subsequent thermal or chemical reduction [115,116]. As the complete removal of the oxygen functional groups caused by the oxidation process may not be complete, the reduced form is commonly referred to as reduced graphene oxide (rGO).…”

Section: Tio2 Systems With Graphene and Other Carbonaceous Materialsmentioning

confidence: 99%

An approach to the photocatalytic mechanism in the TiO2-nanomaterials microorganism interface for the control of infectious processes

Rodríguez-González

Obregón

Patrón-Soberano

et al. 2020

Applied Catalysis B: Environmental

135

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J o u r n a l P r e -p r o o f 2 Graphical Abstract Highlights  Photoactive TiO2 nanomaterials can solve the actual microbial infectious defies  The microbial cell/TiO2 surface approach is key to get the photo-kill mechanism  Microbial preparation requires a reproducible protocol for proper characterization  Advanced surface characterization techniques can unravel the photo-kill mechanism  Generation of ROS, physical injuries and biocidal features confirm the annihilation J o u r n a l P r e -p r o o f Abstract The approach of this timely review considers the current literature that is focused on the interface nanostructure/cell-wall microorganism to understand the annihilation mechanism. Morphological studies use optical and electronic microscopes to determine the physical damage on the cell-wall and the possible cell lysis that confirms the viability and microorganism death. The key parameters of the tailoring the surface of the photoactive nanostructures such as the metal functionalization with bacteriostatic properties, hydrophilicity, textural porosity, morphology and the formation of heterojunction systems, can achieve the effective eradication of the microorganisms under natural conditions, ranging from practical to applications in environment, agriculture, and so on. However, to our knowledge, a comprehensive review of the microorganism/nanomaterial interface approach has rarely been conducted. The final remarks point the ideal photocatalytic way for the effective prevention/eradication of microorganisms, considering the resistance that the microorganism could develop without the appropriate regulatory aspects for human and ecosystem safety. Introduction and background 1. TiO 2 based materials obtained from TiO 2 and its composites J o u r n a l P r e -p r o o f previous studies have demonstrated that photocatalysis can be considered a promising tool in anticancer therapies, since the photocatalyst can kill cancer cells such as HeLa cells, which cause cervical cancer [7]. The energy absorbed by the photocatalyst comprises the range of ultraviolet and/or visible light, even natural sunlight. When the photocatalyst absorbs light, if the energy of the photons is enough to excite the electrons J o u r n a l P r e -p r o o f 6in the valence band (VB), then they migrate to a higher energy level in the conduction band (CB) of the material, as it is illustrated in Fig. 1. This phenomenon generates the charge carriers known as hole-electron pairs. The photogenerated hole can migrate to the surface of the material and react with water molecules or hydroxyl ions to produce hydroxyl radicals, while the photoexcited electron in the conduction band can react with the adsorbed molecular oxygen to produce superoxide ions [8]. Since the report of Fujishima and Honda about the water splitting process using a TiO2 electrode under UV irradiation, numerous studies have exploited the photoactive properties of this material [9,10]. Several reviews have studied the relationship between the electronic properties of TiO2 with...

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High-efficient Synthesis of Graphene Oxide Based on Improved Hummers Method

Cited by 543 publications

References 34 publications

Heteroatom-doped graphene and its application as a counter electrode in dye-sensitized solar cells

Heteroatom-doped graphene and its application as a counter electrode in dye-sensitized solar cells

Use of Nanocomposite Material Based on Graphene Oxide and Silver Nanoparticles in Research of Blood Erythrocytes in Various Diseases

An approach to the photocatalytic mechanism in the TiO2-nanomaterials microorganism interface for the control of infectious processes

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