This paper presents a novel chemical reduction method for graphene oxide (GO) using hydroiodic acid with acetic acid (HI-AcOH) to produce reduced graphene oxide (RG-O). The method is efficient and can be applied to both solution-phase and vapor-phase GO reduction. The resulting RG-O materials exhibit high conductivity and are suitable for mass production. The study demonstrates that the HI-AcOH system effectively removes oxygen functional groups, leading to high graphitization and low defect density. The reduced GO powders, papers, and thin films show improved electrical conductivity compared to those produced using hydrazine, with no nitrogen impurities. The low-temperature process makes it suitable for flexible device fabrication on plastic substrates. The research highlights the potential of this method for advancing the development of high-quality, conductive RG-O materials.This paper presents a novel chemical reduction method for graphene oxide (GO) using hydroiodic acid with acetic acid (HI-AcOH) to produce reduced graphene oxide (RG-O). The method is efficient and can be applied to both solution-phase and vapor-phase GO reduction. The resulting RG-O materials exhibit high conductivity and are suitable for mass production. The study demonstrates that the HI-AcOH system effectively removes oxygen functional groups, leading to high graphitization and low defect density. The reduced GO powders, papers, and thin films show improved electrical conductivity compared to those produced using hydrazine, with no nitrogen impurities. The low-temperature process makes it suitable for flexible device fabrication on plastic substrates. The research highlights the potential of this method for advancing the development of high-quality, conductive RG-O materials.