Nitriles are versatile nitrogen-containing scaffolds that exist extensively in medicines, dyes and useful supplies, and are sometimes synthesized over homogeneous catalysts beneath comparatively harsh situations. Herein, via mimicking the important thing energetic species of hemoglobin p450 heme monooxygenase in most organisms, a Fe–N4 single atom-doped sulfur-containing carbon nitride (Fe/CNS) photocatalyst was facilely ready by one-step thermal polymerization, which was illustrated to be environment friendly for renewable conversion of bio-based alcohols and NH2OH·HCl to a variety of nitriles (80–92% yields) by way of cascade oxidation–ammoxidation at room temperature, or to quantitatively furnish benzaldehyde by way of oxidation within the absence of a nitrogen supply. Theoretical calculations confirmed that the remoted Fe–N4 websites instantly seize photogenerated electrons (e−) and molecular oxygen (O2) to generate superoxide radicals (˙O2−), whereas the encircling S atoms confine photogenerated holes (h+). The excessive effectivity of Fe/CNS within the photo-generation of ˙O2− and holes could contribute to the graceful formation of nitriles by cascade photocatalytic oxidation of alcohol and ammoxidation by way of an in situ shaped oxime, respectively. Furthermore, Fe/CNS was additionally relevant to the selective synthesis of varied imines (83–98% yields) from the oxidation of benzylamines or heterocyclic amines beneath visible-light irradiation, and could possibly be recycled no less than 5 instances with no evident decline in catalytic exercise. The technique of rationally setting up atomic websites to spatially isolate paired electron–holes and kind particular reactive species for enhanced photocatalytic exercise/selectivity supplies an environment friendly and inexperienced method for biomass valorization.