Graphitic　carbon　nitride　(g-C3N4)　hollow　spheres　have　been　prepared　via　one-step　solvothermal　method　without　templates.　The　effects　of　condensation　temperature　on　the　structural,　optical　and　photocatalytic　properties　of　the　samples　were　investigated.　The　X-ray　diffraction　(XRD)　and　Fourier　transformed　infrared　(FTIR)　results　show　that　the　samples　synthesized　at　dissimilar　temperatures　have　graphitic　and　heptazine-based　conjugate　structure.　Optical　analysis　results　evidence　that　the　absorption　edge　shifts　toward　longer　wavelength　and　PL　intensity　quenches　quickly　as　the　treating　temperature　increases　from　120　degrees　C　to　180　degrees　C.　The　results　demonstrate　that　higher　condensation　temperature　improves　the　visible-light　absorption　and　migration　rate　of　photo-induced　carriers　of　samples.　The　g-C3N4　sample　prepared　at　180　degrees　C　presents　a　highest　photocatalytic　degradation　activity　in　the　degradation　of　RhB　under　visible-light　irradiation.　This　study　demonstrates　a　novel　strategy　for　one-step　synthesis　of　hollow　spheres　shaped　polymer　semiconductor　photocatalyst　without　templates.　(C)　2015　Elsevier　B.V.　All　rights　reserved.