Modification　of　graphitic　carbon　nitride　(g-C3N4)　photocatalyst　with　transition　metals　was　achieved　with　a　simple　soft-chemical　approach　using　dicyandiamide　monomer　and　metal　chloride　as　precursors,　in　combination　with　a　thermal-induced　polycondensation　at　600　degrees　C　under　nitrogen　atmosphere.　The　resultant　organic-inorganic　hybrid　materials　were　thoroughly　characterized　by　a　variety　of　techniques,　including　X-ray　diffraction　(XRD),　UV/Vis　spectroscopy,　X-ray　photoelectron　spectroscopy　(XPS),　N-2-sorption,　transmission　electron　microscopy　(TEM),　photoluminescence　(PL),　and　FTIR.　Benzene　hydroxylation　and　styrene　epoxidation　reactions　were　employed　to　evaluate　the　catalytic/photocatalytic　activity　of　the　synthesized　g-C3N4-based　catalysts.　Results　showed　that　Fe-　and　Cu-modified　g-C3N4　were　active　for　the　hydroxylation　of　benzene　to　phenol　using　H2O2　under　mild　conditions.　It　was　also　found　that　g-C3N4　could　promote　the　catalytic　epoxidation　of　styrene　using　molecular　oxygen　as　the　primary　oxidant;　after　modification　with　Co　and　Fe,　the　catalytic　performance　for　styrene　epoxidation　with　O-2　could　be　significantly　improved,　especially　when　coupled　with　visible-light　irradiation.