A　metal-free　protocol　is　established　for　the　decarboxylative　N-H　or　C(sp2)-H　functionalization　of　acidsviametal-free　boron　carbon　nitride　(BCN)　photocatalysis,　delivering　the　desired　products　under　ambient　conditions.　This　methodology　is　applicable　to　the　late-stage　modification　of　pharmaceutical　molecules　and　gram-scale　experiments　as　well　as　in　the　recovery　and　reuse　of　the　photocatalysts　without　the　loss　of　reactivity.　The　developed　photochemical　reaction　system　fulfills　the　requirements　of　green　and　sustainable　chemistry.　©　The　Royal　Society　of　Chemistry　2021.