The effect of DBP of carbon black on the dynamic self-assembly in a polymer melt

Three types of carbon black with different dibutyl phthalate (DBP) absorption have been used to study the electrical percolation behavior in thermoplastic polyurethane.

Preparation of graphene/TiO2 nanotube array photoelectrodes and their photocatalytic activity for the degradation of alachlor

Photocatalytic mechanism scheme of the degradation of alachlor by the GR/TNA photoelectrodes.

Porous CY carbon: a new semiconducting phase with an sp1–sp2–sp3 bonding network

A new porous semiconducting carbon allotrope.

Photoactivity and electronic properties of graphene-like materials and TiO2 composites using first-principles calculations

Electrons in HOMO consisted of O2p from TiO₂ could be directly excited to LUMO composed by the hybridized orbital from GLM and TiO₂ under irradiation. The well-separated electron–hole pairs induced an enhanced photocatalytic activity of TiO₂/GLM.

Facile synthesis of TiO2-RGO composite with enhanced performance for the photocatalytic mineralization of organic pollutants

Current research reports the synthesis of reduced graphene oxide (RGO)-TiO2 nanocomposite by in-situ redox method and graphene oxide by modified hummers method. The ratio of RGO and TiO2 in the composite was optimized to show best photocatalytic activity for the degradation of targeted pollutants. Optimized (1:10) RGO-TiO2 nanocomposite was characterized by various techniques viz. X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller surface area (BET), Raman and diffuse reflectance spectroscopy (DRS) technique confirming successful formation of nanocomposite. XRD results confirm the presence of anatase phase in RGO-TiO2. Uniform dispersion of TiO2 nanoparticles on RGO could be seen from TEM images. The obtained results of (1:10) RGO-TiO2 showed five-fold and two-fold enhancement for the visible light and UV light, respectively, for the photocatalytic mineralization of methylene blue dye as compared to commercial Aeroxide P25 TiO2. The excellent photocatalytic mineralization activity of (1:10) RGO-TiO2 could be attributed to the enhanced surface area of composite as well as to its good electron sink capability. (1:10) RGO-TiO2 could be recycled easily and was found to be equally efficient even after the fourth cycle for the photocatalytic mineralization of methylene blue dye. The non-selectivity of synthesized composite was checked by the mineralization studies of oxalic acid.

Synthesis and application of ternary photocatalyst with a gradient band structure from two-dimensional nanosheets as precursors

A ternary photocatalyst (CNNS/CdS/rGO) with a gradient band structure exhibited prominent photocatalytic performance under visible light irradiation.

A simple ‘in situ’ co-precipitation method for the preparation of multifunctional CoFe2O4–reduced graphene oxide nanocomposites: excellent microwave absorber and highly efficient magnetically separable recyclable photocatalyst for dye degradation

Here, an ‘in situ’ co-precipitation reaction method has been reported for the preparation of CoFe₂O₄–RGO (CF–RGO) nanocomposites.

Chemically reduced graphene oxide–P25–Au nanocomposite materials and their photoelectrocatalytic and photocatalytic applications

CRGO–P25–Au NCMs were prepared through a one-pot chemical reduction method. Photoelectrocatalytic oxidation of methanol with high photocurrent and photocatalytic reduction of Cr(vi) ions to Cr(iii) ions were demonstrated.

Electronic properties and photoactivity of monolayer MoS2/fullerene van der Waals heterostructures

van der Waals (vdW) heterostructures have attracted immense interest recently due to their unusual properties and new phenomena.

Computational study of the structure, UV-vis absorption spectra and conductivity of biphenylene-based polymers and their boron nitride analogues

We calculated electronic and spectral properties of the 1D and 2D carbon and boron nitride materials composed of four-, six- and eight-membered rings by the DFT approach, including the band structure analysis.

A novel & effective visible light-driven TiO2/magnetic porous graphene oxide nanocomposite for the degradation of dye pollutants

A novel & effective visible light-driven TiO₂/magnetic porous graphene oxide nanocomposite synthesized and the nanocatalyst was applied for degrading dye pollutant.

The interactions between TiO2 and graphene with surface inhomogeneity determined using density functional theory

TiO2/graphene composites have shown promise as photocatalysts, leading to improved electronic properties. We have modeled using density functional theory TiO2/graphene interfaces formed between graphene with various defects/functional groups (C vacancy, epoxide, and hydroxyl) and TiO2 clusters of various sizes. We considered clusters from 3 to 45 atoms, the latter a nanoparticle of ∼1 nm in size. Our results show that binding to pristine graphene is dominated by van der Waals forces, and that C vacancies or epoxide groups lead to much stronger binding between the graphene and TiO2. Such sites may serve to anchor TiO2 to graphene. Graphene surfaces with hydroxyls however lead to OH transfer to TiO2 and weak interactions between the graphene and the hydroxylated TiO2 cluster. Charge transfer may occur between TiO2 and graphene in various directions (graphene to TiO2 or TiO2 to graphene), depending on the state of the graphene surface, based on overlap of the density of states. Our work indicates that graphene surface defects or functional groups may have a significant effect on the stability, structure, and photoactivity of these materials.

Polyamine-Mediated Interfacial Assembly of rGO-ZnO Nanostructures: A Bio-inspired Approach and Enhanced Photocatalytic Properties

A bio-inspired approach for the fabrication of reduced graphene oxide (rGO) embedded ZnO nanostructure has been attempted to address issues pertaining to charge recombination and photocorrosion in ZnO for application as an effective photocatalyst. Herein we demonstrate the synthesis of rGO-ZnO nanostructures in a single step using polyamines, which simultaneously aid in the mineralization of ZnO nanostructures from zinc nitrate, reduction of graphene oxide (GO), and finally their assembly to form rGO-ZnO composite structures under environmentally benign conditions. The interspersed nanocomponents in the assembled heterostructures result in enhanced photocatalytic activity under UV light, indicating an effective charge separation of the excited electrons. Furthermore, the composite structure provides stability against photocorrosion for efficient recyclability of the catalyst.

Visible light photocatalytic H2-production activity of wide band gap ZnS nanoparticles based on the photosensitization of grapheme

Visible light photocatalytic H(2) production from water splitting is considered an attractive way to solve the increasing global energy crisis in modern life. In this study, a series of zinc sulfide nanoparticles and graphene (GR) sheet composites were synthesized by a two-step hydrothermal method, which used zinc chloride, sodium sulfide, and graphite oxide (GO) as the starting materials. The as-prepared ZnS-GR showed highly efficient visible light photocatalytic activity in hydrogen generation. The morphology and structure of the composites obtained by transmission electron microscope and x-ray diffraction exhibited a small crystallite size and a good interfacial contact between the ZnS nanoparticles and the two-dimensional (2D) GR sheet,which were beneficial for the photocatalysis. When the content of the GR in the catalyst was 0.1%, the ZG0.1 sample exhibited the highest H(2)-production rate of 7.42 μmol h(−1) g(−1), eight times more than the pure ZnS sample. This high visible-light photocatalytic H(2) production activity is attributed to the photosensitization of GR. Irradiated by visible light, the electrons photogenerated from GR transfer to the conduction band of ZnS to participate in the photocatalytic process. This study presents the visible-light photocatalytic activity of wide bandgap ZnS and its application in H(2) evolution.

Kinetic Study on Mutagenic Chemical Degradation through Three Pot Synthesiszed Graphene@ZnO Nanocomposite

The study was taken up with the objective to synthesize graphene-zinc oxide nano particles (NPs) nanocomposite (Gr@ZnO-Nc) via In-situ synthesis method. The structural, optical, thermal, electrical and photocatalytic properties of the synthesized Gr@ZnO-Nc were studied. The characterization data confirmed that the ZnO NPs were successfully incorporated into the graphene sheets. Further, TGA/DTA results exhibited an enhanced thermal stability of the Gr@ZnO-Nc compared with the graphene. The Gr@ZnO-Nc, graphene sheets were uniformly wrapped by ZnO NPs, which can protect graphene and delay their oxidation in air. The synthesized Gr@ZnO-Nc was used for the efficient photodegradation of a carcinogenic methyl orange (MO) dye. The results exhibited promising photodegradation of the MO dye under UV light irradiation through the production of reactive oxygen species (ROS). The promising effect of Gr@ZnO-Nc on the photodegradation properties was conferred by the large surface area which increased adsorption capacity, and the strong electron transfer ability. Thus, it is encouraging to conclude that the synthesized Gr@ZnO-Nc has environmental significance with its utility in remediation in the hazardous MO dye.

Graphene-Based Photocatalysts for Solar-Fuel Generation

The production of solar fuel through photocatalytic water splitting and CO2 reduction using photocatalysts has attracted considerable attention owing to the global energy shortage and growing environmental problems. During the past few years, many studies have demonstrated that graphene can markedly enhance the efficiency of photocatalysts for solar-fuel generation because of its unique 2D conjugated structure and electronic properties. Herein we summarize the recent advances in the application of graphene-based photocatalysts for solar-fuel production, including CO2 reduction to hydrocarbon fuel and water splitting to H2. A brief overview of the fundamental principles for splitting of water and reduction of CO2 is given. The different roles of graphene in these graphene-based photocatalysts for improving photocatalytic performance are discussed. Finally, the perspectives on the challenges and opportunities for future research in this promising area are also presented.

One-step synthesis of nanocrystalline transition metal oxides on thin sheets of disordered graphitic carbon by oxidation of MXenes

Herein we show that heating 2D Ti3C2 in air results in TiO2 nanocrystals enmeshed in thin sheets of disordered graphitic carbon structures that can handle extremely high cycling rates when tested as anodes in lithium ion batteries. Oxidation of 2D Ti3C2 in either CO2 or pressurized water also resulted in TiO2-C hybrid structures. Similarly, other hybrids can be produced, as we show here for Nb2O5/C from 2D Nb2C.

Graphene-oxide (GO)-Fe3+ hybrid nanosheets with effective sonocatalytic degradation of Reactive Red 120 and study of their kinetics mechanism

This work demonstrates the preparation of graphene-oxide (GO)-Fe(3+) hybrids nanosheets and their high bleaching efficiency on the dye "Reactive Red 120 (RR 120)" by using sonocatalytic degradation. Sonocatalytic degradation was enhanced by using oxidants like PMS (peroxomonosulphate), PDS (peroxodisulphate), H2O2 (hydrogen peroxide) and KIO4 (potassium periodate). Our observations manifested that the degradation of the dye "RR 120" was found to be multiplied by addition of oxidants in the order of PMS>H2O2>PDS>KIO4. The effect of inorganic ions was studied by the addition of SO4(2-), Cl(-), H2PO4(-) and HCO3(-). These results revealed that an addition of inorganic anionic decreases the degradation efficiency of RR 120 at high concentration. The trend of decreased degradation efficiency was SO(-)4<Cl(-)<HPO4. In identical conditions, upon addition of HCO3(-), the degradation rate of RR 120 degradation was increased. As-prepared GO-Fe(3+) hybrid nanosheets were characterised by using X-ray diffraction technique, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy, Raman spectroscopy and Energy Dispersive Analysis of Spectroscopy. Raman and XPS results confirmed the existence of Fe(3+) ions in GO sheet.

Synergistic effect of PtSe2 and graphene sheets supported by TiO2 as cocatalysts synthesized via microwave techniques for improved photocatalytic activity

Here we report a new composite material consisting of TiO₂ nanoparticles grown in the presence of a layered PtSe₂/graphene hybrid as a high-performance photocatalytic material.

A DFT and QTAIM study of the novel d-block metal complexes with tetraoxa[8]circulene-based ligands

The transition metal complexes with the tetraoxa[8]circulene-based ligand are designed. The complexation process strictly depends on matching of the d-metal cation size to the size of the tetraoxa[8]circulene formed cavity.

New insights into the relationship between photocatalytic activity and TiO2–GR composites

Composited graphene cannot enhance the photocatalytic oxidation activity of TiO₂, but can improve its photocatalytic reduction activity and photoelectrochemical properties.

Synthesis of a flower-like CuS/ZnS nanocomposite decorated on reduced graphene oxide and its photocatalytic performance

CZS/rGO composites with enhanced photocatalytic activity have been synthesized. The results demonstrate that the CZS/rGO composites have enormous potential for photodegradation of organic pollutants. The enhanced mechanism was also explained.

Improving the tribological properties of NiAl matrix composites via hybrid lubricants of silver and graphene nano platelets

This work presents a comprehensive study of the synergistic tribological effect of combined solid lubricants of silver and graphene nano platelets (GNPs).

Optical properties of armchair graphene nanoribbons with Stone–Wales defects and hydrogenation on the defects

Armchair graphene nanoribbons display interesting optical properties with the existence of Stone–Wales defects and hydrogenation on the defects.

Nanodiamond based supermolecular nanocomposites: preparation and biocompatibility evaluation

We reported for the first time that water dispersible and biocompatible ND based supermolecular nanocomposites can be facilely and efficiently fabricated via host–guest interactions.

Environmental applications of graphene-based nanomaterials

A critical assessment of recent developments in environmental applications of graphene and graphene-based materials.

Construction of multifunctional films based on graphene–TiO2 composite materials for strain sensing and photodegradation

The obtained multifunctional graphene–TiO₂ composite films showed excellent strain sensing property with gauge factors of 14–35 and enhanced photocatalytic properties.

Zinc oxide based photocatalysis: tailoring surface-bulk structure and related interfacial charge carrier dynamics for better environmental applications

Surface-bulk modification of zinc oxide for efficient photocatalysis.

The synergistic mechanism of graphene and MoS2 for hydrogen generation: insights from density functional theory

The synergistic effect of graphene and MoS₂ was investigated by using density functional theory calculations on the photocatalytic H₂ production activity of TiO₂/graphene/MoS₂ nanoparticles.

Enhanced visible light photocatalytic activity of ZnO doped with down-conversion NaSrBO3:Tb3+ phosphors

ZnO–NaSrBO₃:Tb³⁺ composites were synthesized using microwave-assisted reaction for visible light photocatalytic degradation of methylene blue with a high degradation rate.

Corrosion resistance of graphene directly and locally grown on bulk nickel substrate by laser irradiation

Graphene grown using a laser is superior at resisting the acid corrosive environment for realizing real application in the anti-corrosion field.

Catalytically engineered reduced graphene oxide/ZnO hybrid nanocomposites for the adsorption, photoactivity and selective oil pick-up from aqueous media

Microwave mediated in situ growth of nanocrystalline ZnO on rGO nanosheets is achieved using APTMS as the crosslinking agent. The deposition of hydrophobic ZnO/Si@rGO on a simple cotton textile results in the selective adsorption of oil from aqueous media.

Enhanced photocatalytic degradation of methylene blue and adsorption of arsenic(iii) by reduced graphene oxide (rGO)–metal oxide (TiO2/Fe3O4) based nanocomposites

Hazardous methylene blue dye and As(iii) ions from wastewater are removed by the rGO and TiO₂/Fe₃O₄ based binary and ternary nanocomposites, where ternary rGO–Fe₃O₄–TiO₂ nanocomposite provides maximum degradation and adsorption of the pollutants.

Trends of amino acid adsorption onto graphene and graphene oxide surfaces: a dispersion corrected DFT study

First-principle calculations based on DFT were performed to investigate the adsorption properties of amino acids onto graphene surfaces.

Synthesis of shape-controlled NiO–graphene nanocomposites with enhanced supercapacitive properties

The flowerlike and polyhedral NiO–graphene composites show high supercapacitive performances which were synthesized using a facile hydrothermal method.

Improved interfacial charge transfer and visible light activity of reduced graphene oxide–graphitic carbon nitride photocatalysts

rGO–gCN composites, which were prepared by the in situ photoreduction of GO using bulk gCN as the photocatalyst, exhibited higher photocatalytic activity than bare gCN due to the improved interface charge transfer.

Graphene-based photocatalysts for oxygen evolution from water

Recent achievements of GR-based photocatalysts for oxygen evolution from water are summarized with perspectives on major challenges and opportunities.

A novel heterogeneous hybrid by incorporation of Nb2O5 microspheres and reduced graphene oxide for photocatalytic H2 evolution under visible light irradiation

A novel heterogeneous hybrid composed of Nb₂O₅ microspheres and reduced graphene oxide as photocatalyst exhibits superior photocatalytic activity and stability.