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This text describes the data presented in the paper: Enhanced removal of Nickel (II) from aqueous solutions by SDS-functionalized graphene oxide

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Introductory information
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Files included in the data deposit (include a short description of what data are contained): 

1) Figures?  
2) Tables?
3)


Explain the relationship between multiple data sets, if required: -



Key words used to describe the data:
adsorption, nanomaterials, graphene


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Methodological information
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A brief method description – what the data is, how and why it was collected or created, and how it was processed:

Adsorption experiments were conducted by stirring known amounts of Graphene Oxide (GO) or SDS-functionalized Graphene Oxide (GO-SDS) (ranging from 10 to 100 mg) with 25 mL of aqueous Ni (II) solutions (at concentrations ranging from 5 to 40 mg/L) for predetermined time intervals at room temperature (298 K). The samples were filtered (Millipore, pore size 0.45 micro m) and concentrations were measured spectrophotometrically. Experiments measuring the kinetics of adsorption and the effect of pH were conducted using the same method. pH adjustment of Ni (II) solutions was achieved by adding concentrated HCl or NaOH to the solutions. Control experiments, with no adsorbent added to the solutions, were performed for each series of measurements. Experiments were conducted in triplicate under identical conditions and results were found to be reproducible (with an experimental error of approximately 3%). In order to calculate the concentration retained in the adsorbent phase (q, mg/g), the following equation was used: q=(C0-C)*V/W
where, C0 is the initial concentration of the adsorbate (mg/L) and C is the final concentration of the adsorbate (mg/L). V is the volume of the solution (L) and W is the mass of adsorbent (g) used in the experiments. 


Instruments, hardware and software used: 
The concentrations of the Ni (II) solutions were measured by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES / UNICAM 701 Series Emission Spectrometer) and a UV-Visible spectrophotometer (Cary 100 UV-Vis) by applying the Dimethylglyoxime method. Fourier transform infrared (FTIR) spectra of the samples were recorded with a Varian 800 FTIR spectrometer and Raman spectra with a WiTec Confocal Raman Microscope, model CRM 200, UIm Germany using an excitation wavelength of488 nm. Scanning electron microscopy (SEM) measurements were performed on a XL30 ESEM-FEG microscope. A zetasizer Nano ZS (Malvern) was used for zeta potential measurements using the setting for a polystyrene standard. Size of the samples were estimated by TEM from Philps CM-100 with a tungsten filament. Microsoft Excel was used for calculations.


Date(s) of data collection: 
November 2013 - April 2014


Geographic coverage of data:



Data validation (how was the data checked, proofed and cleaned):
Experiments were conducted in triplicate under identical conditions and results were found to be reproducible (with an experimental error of approximately 3%). 


Overview of secondary data, if used:



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Data-specific information
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Definitions of names, labels, acronyms or specialist terminology uses for variables, records and their values: 
GO : Graphene Oxide
GO-SDS : SDS-functionalized Graphene Oxide


Explanation of weighting and grossing variables: 
C0 : the initial concentration of the adsorbate (mg/L) 
C : the final concentration of the adsorbate (mg/L) 
V : the volume of the solution (L) 
W : the mass of adsorbent (g) used in the experiments
q : concentration retained in the adsorbent phase (q, mg/g)
Q : adsorption capacity (mg/g, calculated by Langmuir model) 


Outline any missing data:



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Contact
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Please contact rdm@ncl.ac.uk for further information