Diatomite,　composed　of　amorphous　macroporous　hydrated　silica,　has　generated　increasing　attention　as　an　attractive　raw　material　for　elimination　of　heavy　metal,　while　suffering　low　surface　activity.　Herein,　easily　separable　diatomite　adsorbents　modified　by　Zn　compounds　are　developed　for　effective　adsorption　of　Pb(II),　Cu(II)　and　Cd(II)　ions　and　sunlight　photoreduction　of　toxic　Cr(VI)　to　low-toxic　Cr(III).　The　micro-structure　and　functionality　are　characterized　through　energy　spectrum　and　spectroscopic　analysis.　Sulfion　S2−　or　carbonyl　COO−　interlinked　networks　on　the　modified　diatomite　are　effective　for　capturing　Pb(II),　Cu(II)　and　Cd(II)　ions,　and　are　capable　of　being　oxidized　to　generate　diatomite@ZnO　directly　at　450　°C　in　air　atmosphere.　Significantly,　by　recycling　the　used　diatomite@ZnS　(Dt@ZnS)　adsorbents　loaded　by　Cu(II)　and　Cd(II)　ions,　Cu　or　Cd　doped　ZnO　photocatalysts　can　be　fabricated　on　diatomite　to　vary　band　gap　energy　of　ZnO　for　more　efficient　absorption　of　visible　light　for　Cr(VI)　photoreduction　under　sunlight　irradiation.　Although　the　derivatives　exhibit　weakened　Cr(VI)　photoreduction　capacity　compared　with　Dt@ZnS　precursor,　probably　owing　to　the　influence　of　surface　deposits　of　Cu(II)　or　Cd(II)　on　doping　efficiency　and　light　absorption,　this　idea　offers　a　promising　solution　to　convert　the　used　adsorbents　loaded　by　poisonous　heavy　metals　into　photocatalysts　for　secondary　utilization　in　waste　water　purification,　thus　making　it　possible　to　produce　tailor-made　materials　for　specific　requirements　alternative　by　the　reutilization　of　discarded　heavy　metal　adsorbents.　©　2020　Elsevier　B.V.