Photocatalytic　materials　for　photocatalysis　is　recently　proposed　as　a　promising　strategy　to　address　environmental　remediation.　Metal-free　graphitic　carbon　nitride　(g-C3N4),　is　an　emerging　photocatalyst　in　sulfate　radical　based　advanced　oxidation　processes.　The　solar-driven　electronic　excitations　in　g-C3N4　are　capable　of　peroxo　(OO)　bond　dissociation　in　peroxymonosulfate/peroxydisulfate　(PMS/PDS)　and　oxidants　to　generate　reactive　free　radicals,　namely　SO4•−　and　OH•　in　addition　to　O2•−　radical.　The　synergistic　mechanism　of　g-C3N4　mediated　PMS/PDS　photocatalytic　activation,　could　ensure　the　generation　of　OH•　radicals　to　overcome　the　low　reductive　potential　of　g-C3N4　and　fastens　the　degradation　reaction　rate.　This　article　reviews　recent　work　on　heterojunction　formation　(type-II　heterojunction　and　direct　Z-scheme)　to　achieve　the　bandgap　for　extended　visible　light　absorption　and　improved　charge　carrier　separation　for　efficient　photocatalytic　efficiency.　Focus　is　placed　on　the　fundamental　mechanistic　routes　followed　for　PMS/PDS　photocatalytic　activation　over　g-C3N4-based　photocatalysts.　A　particular　emphasis　is　given　to　the　factors　influencing　the　PMS/PDS　photocatalytic　activation　mechanism　and　the　contribution　of　SO4•−　and　OH•　radicals　that　are　not　thoroughly　investigated　and　require　further　studies.　Concluding　perspectives　on　the　challenges　and　opportunities　to　design　highly　efficient　persulfate-activated　g-C3N4　based　photocatalysts　toward　environmental　remediation　are　also　intensively　highlighted.　©　2021　Elsevier　B.V.