A　sandwich　structured　Fe3O4/Ag/m(TiO2-ZrO2)　magnetic　nanosphere　with　Ag　nanoparticles　as　an　interim　layer　was　fabricated　with　in　situ　deposition　of　Ag　nanoparticles　onto　Fe3O4　nanospheres　and　subsequent　coating　an　outmost　shell　of　mesoporous　TiO2-ZrO2.　As　compared　to　Fe3O4/m(TiO2-ZrO2)/Ag　with　Ag　nanoparticles　as　the　outmost　layer,　unique　Fe3O4/Ag/m(TiO2-ZrO2)　sandwich　nanospheres　possess　higher　efficient　charge　migration　and　larger　specific　surface　area　disclosed　by　the　BET　and　photoelectrochemical　characterizations,　so　they　present　improved　photocatalytic　activity　toward　Cr(VI)　reduction.　In　addition,　they　have　high　thermal　stability　because　mesoporous　TiO2-ZrO2　outmost　shell　could　protect　the　interim　Ag　nanoparticles　from　damage　and　agglomeration　at　high　temperature.　Results　showed　reduction　efficiency　of　Cr(VI)　of　Fe3O4/Ag/m(TiO2-ZrO2)　reached　98.4　%　in　30　min,　as　1.6　times　as　that　of　Fe3O4/m(TiO2-ZrO2)/Ag.　The　Fe3O4/Ag/m(TiO2-ZrO2)　still　obtained　91.3　%　and　87.9　%　reduction　ratio　after　calcination　at　500　and　recycling　5　times,　respectively.　The　photocatalytic　mechanism　was　also　revealed　by　scavenger　experiments　and　ERP　analysis.　This　work　provided　a　good　example　for　further　design　and　preparation　of　magnetic　photocatalysts　with　high　performance　for　the　remediation　of　heavy　metal　pollutants.　©　2022　Elsevier　B.V.