This　study　describes　the　preparation　of　graphitic　carbon　nitride　(g-C3N4),　hematite　(alpha-Fe2O3),　and　their　g-C3N4/alpha-Fe2O3　heterostructure　for　the　photocatalytic　removal　of　methyl　orange　(MO)　under　visible　light　illumination.　The　facile　hydrothermal　approach　was　utilized　for　the　preparation　of　the　nanomaterials.　Powder　X-ray　diffraction　(XRD),　Scanning　electron　microscopy　(SEM),　Energy　dispersive　X-ray　(EDX),　and　Brunauer-Emmett-Teller　(BET)　were　carried　out　to　study　the　physiochemical　and　optoelectronic　properties　of　all　the　synthesized　photocatalysts.　Based　on　the　X-ray　photoelectron　spectroscopy　(XPS)　and　UV-visible　diffuse　reflectance　(DRS)　results,　an　energy　level　diagram　vs.　SHE　was　established.　The　acquired　results　indicated　that　the　nanocomposite　exhibited　a　type-II　heterojunction　and　degraded　the　MO　dye　by　97%.　The　degradation　ability　of　the　nanocomposite　was　higher　than　that　of　pristine　g-C3N4　(41%)　and　alpha-Fe2O3　(30%)　photocatalysts　under　300　min　of　light　irradiation.　The　formation　of　a　type-II　heterostructure　with　desirable　band　alignment　and　band　edge　positions　for　efficient　interfacial　charge　carrier　separation　along　with　a　larger　specific　surface　area　was　collectively　responsible　for　the　higher　photocatalytic　efficiency　of　the　g-C3N4/alpha-Fe2O3　nanocomposite.　The　mechanism　of　the　nanocomposite　was　also　studied　through　results　obtained　from　UV-vis　and　XPS　analyses.　A　reactive　species　trapping　experiment　confirmed　the　involvement　of　the　superoxide　radical　anion　(O-2(&　BULL;-))　as　the　key　reactive　oxygen　species　for　MO　removal.　The　degradation　kinetics　were　also　monitored,　and　the　reaction　was　observed　to　be　pseudo-first　order.　Moreover,　the　sustainability　of　the　photocatalyst　was　also　investigated.