Development of efficient and robust photoelectrochemical systems compromised of semiconductor electrodes which harness light to drive useful chemical transformations is hindered by a paucity of appropriate protective coatings to enable operation in aqueous media. Optically transparent, electrically conductive and physically stable coatings must be generated in order to avoid deleterious surface reactions associated with the corrosion and passivation of the semiconductor in solution. Graphene is the thinnest protective coating (0.3 nm) shown to extend stability of a semiconductor in aqueous solution, due in part to its relative impermeability to most gases and liquids. However, large-scale graphene growth via chemical vapor deposition – vital to integration of graphene into commercial devices – yields polycrystalline graphene, which contains a number of defects, such as dangling bonds found at grain boundaries and the edges of a sheet or point dislocations found within the sheet. This work demonstrated that capping these defects utilizing fluorine moieties can lead to significantly enhanced stability of silicon photoanodes under anodic conditions in aqueous media, which are typically too harsh for carbon-based layers to withstand for extended periods of time. N-type silicon (n-Si) (111) photoelectrodes with a hydride surface functionalization were biased anodically at short-circuit in aqueous Fe(CN)₆^3-/4- under illumination (∼33 mW cm^–2 ENH-type W-halogen lamp), and the generated photocurrent was observed to decay almost to zero within 100s, consistent with rapid corrosion of the semiconductor. In comparison, identical photoelectrodes protected with a single sheet of fluorinated graphene (F–Gr) demonstrated photocurrent densities of ~ 10 mA cm^-2 for > 100,000s (> 24h). X-ray photoelectron spectra collected before and after exposure to aqueous anodic conditions showed that oxide formation was significantly inhibited for the n-Si electrodes covered with F–Gr in comparison with bare n-Si–H electrodes tested under the same conditions. Variations in the open-circuit voltage (V_OC) in contact with several different redox couples with formal potentials that span the bandgap of silicon indicated that the photoanodes coated with F–Gr did not form a buried junction with respect to solution, which shows promise for the use of F–Gr as a protective layer for semiconductors beyond silicon. In addition, n-Si photoanodes coated with F–Gr exposed to a HBr/Br₂ electrolyte solution under anodic conditions showed enhanced stability and formed a halide-splitting cell with up to 5% efficiency with the addition of a platinum catalyst, demonstrating that these protective layers can successfully be integrated into devices for the production of chemical fuels.