Pyrophosphate　acid/graphene　composites　were　prepared　by　using　graphite　oxide　and　phosphorus　trichloride　as　raw　materials.　Phosphorus-based　groups　and　residual　oxygenated　functional　groups　may　reduce　graphene　sheet　restacking　to　form　graphite.　The　stacked　pore　size　and　binding　site　of　the　composites　are　noticeably　improved　by　aggregation　of　functionalized　sheets.　The　average　interlayer　spacing　of　the　composites　is　wider　than　that　of　reduced　graphene　oxide　(RGO).　Compared　with　the　high　surface　area　of　the　adsorbent,　the　porosity　and　pore　size　of　the　materials　exert　significantly　greater　influence　on　the　adsorption　capacity　of　the　composites.　The　adsorption　process　follows　second-order　rate.　The　adsorption　of　methylene　blue　preferably　fitting　the　Langmuir　adsorption　isotherm　suggests　monolayer　coverage　of　adsorbed　molecules.　The　adsorption　capacity　of　the　composites　for　methylene　blue　is　200.0　mg　g(-1),　which　is　significantly　higher　than　those　of　RGO　(80.0　mg　g(-1))　and　active　carbon　(46.7　mg　g(-1)).　(C)　2014　Elsevier　B.V.　All　rights　reserved.