Time filter

Source Type

Ding C.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Cheng W.,Sichuan University | Sun Y.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wang X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells
Dalton Transactions | Year: 2014

The chemical affinity of graphene oxide (GO) nanosheets with radionuclides (Eu(iii) and U(vi)) was determined by macroscopic, spectroscopic and modeling techniques. The macroscopic results showed that the adsorption of Eu(iii) and U(vi) on GO nanosheets was independent of ionic strength, indicating that inner-sphere surface complexation predominated their adsorption. The maximum adsorption capacities calculated from a Langmuir model at pH 4.0 and T = 303 K were 208.33 mg U(vi) and 28.70 mg Eu(iii) per gram of GO nanosheets, respectively. No hysteresis was observed for both Eu(iii) and U(vi) on GO nanosheets when desorption was initiated by lowering solution pH. While desorption was induced by replacing the radionuclide supernatant liquid with radionuclide-free electrolyte solution, the adsorption-desorption hysteresis was observed for U(vi) but not for Eu(iii), indicating that the chemical affinity of GO nanosheets with U(vi) was stronger than that of GO nanosheets with Eu(iii). The adsorption behaviors of Eu(iii) and U(vi) on GO nanosheets can be fitted by a double diffuse layer surface complexation model with the mononuclear monodentate >SOM(n-1)+ and >SOMOH(n-2)+ complexes, and larger log K values of U(vi) was observed as compared to those of Eu(iii). According to the spectroscopic analysis, the irreversible adsorption of U(vi) on GO nanosheets at variable radionuclide concentrations was attributed to the oxygen-containing functional groups. © 2014 The Royal Society of Chemistry.


Zhao G.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Li J.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Jiang L.,CAS Beijing National Laboratory for Molecular | Dong H.,CAS Beijing National Laboratory for Molecular | And 2 more authors.
Chemical Science | Year: 2012

A facile method to synthesize layered manganese oxide nanosheets was developed for the first time by using graphene oxide as a template. The in situ replacement of carbon atoms on the graphene oxide framework by edge-shared [MnO 6] octahedra provides a new methodology to synthesize graphene-based two-dimensional nanomaterials. The transformation of graphene oxide into δ-type MnO 2 nanosheets results in an especially high surface area (157 m 2 g -1), which is the highest value amongst today's MnO 2 nanomaterials. Moreover, the MnO 2 nanosheets demonstrated prominent capacitance (∼1017 F g -1 at a scan rate of 3 mV s -1, and ∼1183 F g -1 at a current density of 5 A g -1) and remarkable rate capability (∼244 F g -1 at a high scan rate of 50 mV s -1 and ∼559 F g -1 at a high current density of 25 A g -1), indicating their promise in high energy and power density pseudosupercapacitors. © 2012 The Royal Society of Chemistry.


Yang S.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wu X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Chen C.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Dong H.,CAS Beijing National Laboratory for Molecular | And 2 more authors.
Chemical Communications | Year: 2012

This work reports a new graphene-based composite for supercapacitor material, and the maximum specific capacitance of 1760.72 F g -1 at a scan rate of 5 mV s -1, with excellent cycling stability. This journal is © The Royal Society of Chemistry 2012.


Wang Q.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wang X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wang X.,Soochow University of China | Chai Z.,Soochow University of China | Hu W.,CAS Beijing National Laboratory for Molecular
Chemical Society Reviews | Year: 2013

Carbon nanotubes (CNTs) and graphene, and materials based on these, are largely used in multidisciplinary fields. Many techniques have been put forward to synthesize them. Among all kinds of approaches, the low-temperature plasma approach is widely used due to its numerous advantages, such as highly distributed active species, reduced energy requirements, enhanced catalyst activation, shortened operation time and decreased environmental pollution. This tutorial review focuses on the recent development of plasma synthesis of CNTs and graphene based materials and their electrochemical application in fuel cells. This journal is © The Royal Society of Chemistry.


Moniz S.J.A.,University College London | Zhu J.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Tang J.,University College London
Advanced Energy Materials | Year: 2014

The most important factors dominating solar hydrogen synthesis efficiency include light absorption, charge separation and transport, and surface chemical reactions (charge utilization). In order to tackle these factors, an ordered 1D junction cascade photoelectrode for water splitting, grown via a simple low-cost solution-based process and consisting of nanoparticulate BiVO4 on 1D ZnO rods with cobalt phosphate (Co-Pi) on the surface is synthesized. Flat-band measurements reveal the feasibility of charge transfer from BiVO4 to ZnO, supported by PL measurements and photocurrent observation in the presence of an efficient hole scavenger, which demonstrate that quenching of luminescence of BiVO4 and enhanced current are caused by electron transfer from BiVO4 to ZnO. A dramatic cathodic shift in onset potential under both visible and full arc irradiation, coupled with a 12-fold increase in photocurrent (ca. 3 mA cm-2) are observed compared to BiVO 4, resulting in ≈47% IPCE at 410 nm (4% for BiVO4) with high solar energy conversion efficiency (0.88%). The reasons for these enhancements stem from enhanced light absorption and trapping, in situ rectifying electron transfer from BiVO4 to ZnO, hole transfer to Co-Pi for water oxidation, and facilitating electron transport along 1D ZnO. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wu X.-L.,Anhui University of Science and Technology | Wu X.-L.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wen T.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Guo H.-L.,Anhui University of Science and Technology | And 3 more authors.
ACS Nano | Year: 2013

As a newly developed material, carbon gels have been receiving considerable attention due to their multifunctional properties. Herein, we present a facile, green, and template-free route toward sponge-like carbonaceous hydrogels and aerogels by using crude biomass, watermelon as the carbon source. The obtained three-dimensional (3D) flexible carbonaceous gels are made of both carbonaceous nanofibers and nanospheres. The porous carbonaceous gels (CGs) are highly chemically active and show excellent mechanical flexibility which enable them to be a good scaffold for the synthesis of 3D composite materials. We synthesized the carbonaceous gel-based composite materials by incorporating Fe 3O4 nanoparticles into the networks of the carbonaceous gels. The Fe3O4/CGs composites further transform into magnetite carbon aerogels (MCAs) by calcination. The MCAs keep the porous structure of the original CGs, which allows the sustained and stable transport of both electrolyte ions and electrons to the electrode surface, leading to excellent electrochemical performance. The MCAs exhibit an excellent capacitance of 333.1 F·g-1 at a current density of 1 A·g -1 within a potential window of -1.0 to 0 V in 6 M KOH solution. Meanwhile, the MCAs also show outstanding cycling stability with 96% of the capacitance retention after 1000 cycles of charge/discharge. These findings open up the use of low-cost elastic carbon gels for the synthesis of other 3D composite materials and show the possibility for the application in energy storage. © 2013 American Chemical Society.


Ren X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Li J.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Tan X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wang X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells
Dalton Transactions | Year: 2013

This paper presents a comparative study of Cu(ii) decontamination by three different carbonaceous materials, i.e., graphene oxide, multiwalled carbon nanotubes, and activated carbon. The three carbonaceous materials were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, N2-BET surface area analysis, and potentiometric acid-base titrations in detail. Also, Cu(ii) adsorption on the three types of carbonaceous materials as a function of pH and Cu(ii) ion concentration were investigated. The constant capacitance model was used to determine the appropriate surface reactions of Cu(ii) adsorption on carbonaceous materials with the aid of FITEQL 4.0 software. In addition, how the surface area and the total concentration of acidic functional groups influencing the adsorption capacities of the three carbonaceous materials for Cu(ii) removal were elucidated. The results have an important role in predicting the adsorption capacity of surface modified carbonaceous materials. © 2013 The Royal Society of Chemistry.


Zhao G.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wen T.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Chen C.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wang X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells
RSC Advances | Year: 2012

As a fascinating two-dimensional carbon allotrope, graphene has triggered a 'gold rush' all over scientific research areas especially since the Nobel Prize for Physics in 2010. To exploit the prominent properties of graphene-based nanomaterials, two important problems are focused in this review: one is the synthesis of these graphene-based nanomaterials with different kinds of well-defined structures, and the other is the effective application of them as active nanomaterials in functional devices or processes. In this critical review, from the viewpoint of chemistry and materials, we give a brief overview of the recent significant advances in the synthesis of graphene-based nanomaterials and their applications in energy-related areas and environmental pollution remediation areas, including supercapacitors, lithium ion batteries, solar cells, adsorption, and degradation of organic/inorganic pollutants from large volumes of aqueous solutions in environmental pollution cleanup. The main challenges and perspectives of the materials for future research are also discussed. © The Royal Society of Chemistry. 2012.


Yang S.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Guo Z.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Sheng G.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wang X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells
Science of the Total Environment | Year: 2012

The increasing exploitation of multi-walled carbon nanotubes (MWCNTs) into many industrial processes has raised considerable concerns as they are likely to be released into the environment. The interactions of the pollutants in water with discharged MWNCTs will further influence the environmental behavior and fate of these contaminants. In this context, our work aims to quantify the sequestration mechanisms and species distribution of Cd(II) and 1-naphthol on discharged MWCNTs by using batch technique. The uptake of Cd(II) on oxidized MWCNTs is greatly enhanced by the coexistent 1-naphthol, whereas the uptake of 1-naphthol on oxidized MWCNTs is not influenced by the coexistent Cd(II) in solution. Based on the experimental results, one can deduce that ion exchange or outer-sphere surface complexation mainly contributes to Cd(II) uptake on oxidized MWCNTs at low pH values, and inner-sphere surface complexation is the main uptake mechanism at high pH values. The uptake of 1-naphthol on oxidized MWCNTs is attributed to the π-π conjugate action between the aromatic ring of 1-naphthol and the graphitic structure of oxidized MWCNTs. The above-mentioned laboratorial results are further verified by the investigation conducted in actual effluent disposal system. The findings in the present study can provide more precise information on the real impact and changes in aqueous environment caused by the simultaneous presence of Cd(II), 1-naphthol and discharged oxidized MWCNTs. © 2012 Elsevier B.V.


Zhao D.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Sheng G.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Chen C.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells | Wang X.,CAS Hefei Key Laboratory of Novel Thin Film Solar Cells
Applied Catalysis B: Environmental | Year: 2012

Electron-hole recombination limits the efficiency of TiO 2. We have investigated the efficacy with which the graphene@TiO 2 " dyade" -like structure reduced charge recombination and enhanced reactivity. A visible-light photocatalysis of graphene@TiO 2 " dyade" -like structure was synthesized, and photocatalytic degradation of organic compounds over the UV and visible-light spectrum regions was investigated. The graphene@TiO 2 had anatase phase and was able to absorb a high amount of photo energy in the visible-light region, driving effectively photochemical degradation reactions. There were more OH radicals produced by the graphene@TiO 2 (1:3) than by pure TiO 2 under UV and visible-light irradiation. Graphene can enhance the photocatalytic activity of TiO 2 in two aspects, namely, e - transportation and adsorption. This work provides new insight into the fabrication of graphene@TiO 2 as a high performance visible-light photocatalyst and facilitates its application in photocatalytic degradation of organic compounds. © 2011 Elsevier B.V.

Loading CAS Hefei Key Laboratory of Novel Thin Film Solar Cells collaborators
Loading CAS Hefei Key Laboratory of Novel Thin Film Solar Cells collaborators