Heteroatom-doping into graphitic networks has been utilized for opening the band gap of graphene. However, boron-doping into the graphitic framework is extremely limited, whereas nitrogen-doping is relatively feasible. Herein, boron/nitrogen co-doped graphene (BCN-graphene) is directly synthesized from the reaction of CCl4, BBr3, and N2 in the presence of potassium. The resultant BCN-graphene has boron and nitrogen contents of 2.38 and 2.66 atom %, respectively, and displays good dispersion stability in N-methyl-2-pyrrolidone, allowing for solution casting fabrication of a field-effect transistor. The device displays an on/off ratio of 10.7 with an optical band gap of 3.3 eV. Considering the scalability of the production method and the benefits of solution processability, BCN-graphene has high potential for many practical applications. Mixing it up a bit: B/N-doped graphene was directly synthesized from the reaction of CCl4, BBr3, and N2 in the presence of potassium. It has good dispersibility in N-methyl-2-pyrrolidone, allowing solution casting for the fabrication of field-effect transistors with an on/off ratio of 10.7 and an optical band gap of 3.3 eV. The method is scalable and solution processable, making it suitable for many applications.