Elucidating the influence of residual polymer and gas environment on the electronic structure of a graphene layer using in situ APXPS

•Designing the APXPS analysis to characterize the graphene electronic structure under real gas environment.•Clarifying the differences in influence between the organic residue on Gr and gas environment on the Gr electronic structure.•Verification of the reliability of APXPS for the electronic structure change in Gr at controlled gas environment.•Verification of little change in Gr chemical/electronic structure despite heat treatment in near ambient gas environment.