Fig. 4  in the attached paper shows the two characteristic phonon frequencies in the K point: approx. 1350cm-1 and approx. 1200cm-1. Maybe yours 2400cm-1 is obertone of 1200cm-1? Exhibiting of this Raman line maybe due to possible selection rules alterating in nonideal graphene.

The preicse position of "D peak" is also interesting. Is it higher than 1330cm-1?

Thank you for response.

Yes, the position of D peak is 1341cm-1 approximately.

Could you clarify a little bit what you meant under selection rules  ?

Through the raman spectrum. I suggest you measure at many point on your sample. I dont want to give any comments now . You can see by microscope before measure raman.... please contact to doctor Duong Dinh Loc. He have many experiences in graphene synthesis by CVD method. 

https://www.researchgate.net/profile/Loc_Duong_Dinh?_sg=NLmZgdQoj4MHrrawO_f-8wyVWVUP6sl03hwOQGeA9WHj21bRqmcUCQ4g8qP8n9k-dhhI9Yip5tHryAhogvudcQ

Your spectrum does not correspond to graphene or graphite, is dissordered sp2 carbone matherial with some imputy. To see graphene spectrum search woks of Ferrary or Game ( Nobel prizewinner), they present picture for mono, di and multi layer graphene materials. From my experiene the monolayer picture is

Hi Aliya,

check this paper, 

https://www.researchgate.net/publication/259992703_Effect_of_ball_milling_on_graphene_reinforced_Al6061_composite_fabricated_by_semi-solid_sintering

We were trying to evaluate the damage happened  in the graphene after ball milling. we have a peak at the same position. this peak is the 2D-band. in the paper we have a complete explanation and analysis of all the peaks and specially the 2 D peak. also we have a interpretation of what the change in the peaks value and position means. it is a reach section in the paper and i believe it will answer your question.

Article Effect of ball milling on graphene reinforced Al6061 composi...

Thanks all for response,

especially Dr. Yevgeni Vasilievich and Dr. Rinat Aysin,

your comments are very useful.

Dear  Dr. Aurelio,

I try to synthesize graphene on liquid metallic substrate. Is it possible that the presence of metallic particles in my  sample distort the spectrum?

P.S.: I switched off  the lights of course

Dear Dr. Aurelio,

I have redone Raman for my sample (covering it by paper sheet) and found You are absolutely right.

Thank you so much.

I attached the new spectrum, could you please look at it again. 

Actually first part 100-800cm-1  is still load by peaks.

This link is really useful,

http://www.instanano.com/characterization/experimental/raman-graphene/

See attach. M.K.

In contrast, the Raman spectrum of BHOPG shows new features compared to HOPG, with the 1367-, 1620-, and 2950-cm-' bands being apparent in the ordered material, in addition to the expected bands at 1585, 2722, 2450, and 3240 cm-'.

refer

Raman Spectroscopy of Carbon Materials: Structural Basis of Observed Spectra 557 Yan Wang, Daniel C. Alsmeyer, and Richard L. McCreery"