Graphite-like　carbon　nitride　(g-C3N4)　was　innovatively　modified　by　diethylphosphinic　acid　through　hydrogen　bonding;　g-C3N4/organic　aluminum　diethylhypophosphites　(g-C3N4/DAHPi)　hybrid　(denoted　as　CDAHPi)　was　synthesized　by　salification　reactions,　and　subsequently　incorporated　into　PS　matrix　to　prepare　composites　through　melt　blending　method.　Thermal　data　showed　that　g-C3N4　could　protect　DAHPi　from　external　heat,　leading　to　improved　thermal　stability　of　DAHPi.　Moreover,　it　was　found　that　the　introduction　of　the　hybrid　reduced　the　values　of　heat　release　rate　(HRR)　and　total　heat　release　(THR)　of　the　composites.　Compared　with　those　of　pure　PS,　the　HRR　and　THR　of　PS/CDAPHi4　decreasing　by　43%　and　21%　respectively　were　observed　at　loadings　as　low　as　4.0 wt%.　The　PS/CDAHPi　exhibited　an　additional　advantage　in　suppression　of　pyrolysis　gas　production　in　comparison　with　neat　PS.　In　addition,　the　additive　showed　higher　interfacial　adhesion　with　PS.　©　2017　Elsevier　Ltd