An　integrated　microfluidic　planar　reactor　is　essential　for　achieving　efficient　and　enhanced　photocatalytic　water　treatment.　Optimization　of　catalysts　is　an　area　of　intense　study　owing　to　the　need　to　enhance　the　performances　of　microreactors.　A　high-efficiency　photocatalytic　microreactor　is　presented　here　by　combining　a　planar　microreactor　with　a　high-efficiency　photocatalyst.　TiO2　nanoparticles　doped　with　Y　and　Yb　were　prepared　to　improve　the　photocatalytic　reaction　efficiency.　First,　better　performance　is　achieved　with　the　Y,　Yb/TiO2　and　TiO2　microreactors　than　conventional　bulk　reactors　because　of　good　photodegradation　and　a　high　reaction　rate.　Then,　the　Y,　Yb/TiO2　film　microreactor　exhibits　not　only　efficient　catalytic　activity　with　UV　light　but　also　higher　photocatalytic　activity　under　visible　light　irradiation　than　that　achieved　by　a　TiO2　film　microreactor.　The　reaction　rate　constant　of　the　Y,　Yb/TiO2　film　microreactor　is　approximately　0.530 s–1,　which　is　twice　that　of　the　TiO2　film　microreactor.　Moreover,　the　performances　under　continuous　and　intermittent　reactions　are　compared　to　evaluate　the　stability　of　the　microreactor,　thereby　building　the　foundation　for　practical　application　of　continuous　water　treatment　in　the　microreactor.The　planar　microreactor　provides　a　convenient　platform　for　studying　photodegradation　under　various　conditions,　such　as　different　temperatures,　flow　rates,　light　irradiation　(UV　and　Vis),　and　reaction　modes　(continuous　and　intermittent).　Copyright　©　2024　Ge,　Wei,　Hu,　Xie,　Wang,　Li　and　Qiu.