Hexagonal　ZnS　nanostructured　spheres　self-assembled　from　ZnS　nanocrystals　had　been　synthesized　at　a　low　temperature　of　100　degrees　C　by　using　L-cysteine　(an　ordinary　amino　acid)　as　a　sulfur　source　and　gelatin　(an　ordinary　amino　acid)　as　the　assembling　agent.　The　reaction　time,　L-cysteine　and　gelatin　all　played　key　roles　in　the　formation　of　ZnS　spheres.　By　combining　the　results　of　X-ray　diffraction　(XRD),　transmission　electron　microscope　(TEM),　field-emission　scanning　electron　microscopy　(FESEM),　ultraviolet-visible　(UV-vis)　absorption　and　photoluminescence　(PL)　spectra,　a　structural　and　morphological　characterization　of　the　products　was　performed.　The　photocatalytic　activity　of　ZnS　spheres　had　been　tested　by　degradation　of　Rhodamine-B　(RB)　under　UV　light　compared　to　commercial　Degussa　P-25　TiO2　and　that　of　ZnS　prepared　without　gelatin　or　with　other　sulfur　source,　indicating　that　ZnS　spheres　synthesized　by　using　L-cysteine　and　gelatin　exhibit　enhanced　photocatalytic　activity　for　degradation　of　RB.　(C)　2009　Elsevier　B.V.　All　rights　reserved.