A facile all-chemical vapor deposition approach is designed, which allows both sequentially grown Gr and monolayer MoS2 in the same growth process, thus allowing the direct construction of MoS2/Gr vertical heterostructures on Au foils. A weak n-doping effect and an intrinsic bandgap of MoS2 are obtained from MoS2/Gr/Au via scanning tunneling microscopy and spectroscopy characterization. The exciton binding energy is accurately deduced by combining photoluminescence measurements.