Modified　BCN　(m-BCN)　nanosheets　are　synthesized　by　a　KCl-assisted　molten　salt　strategy　with　boric　acid,　glucose,　and　urea　as　precursors.　The　as-obtained　m-BCN　nanosheets　show　decreased　thickness,　enhanced　crystallinity,　and　improved　charge　separation　compared　with　those　of　bulk　BCN.　The　photo-electrochemical　tests,　photoluminescence　spectra,　and　electron　paramagnetic　resonance　data　indicate　that　the　separation/transfer　kinetics　of　photoinduced　charge　carriers　are　promoted.　The　m-BCN　nanosheets　exhibit　improved　efficiency　in　oxygenation　of　hydrocarbons　(up　to　99%)　and　thioether　and　deoxygenation　of　nitrobenzene　and　sulfoxides　with　visible　light.　The　protocol　brings　forth　broader　applications　of　metal-free　BCN　ceramic　semiconductors　in　organic　transformations.