Photocatalytic and photoluminescence properties of CePO4 nanostructures prepared by coprecipitation method and thermal treatment

•CePO4 polymorphs are obtained by coprecipitation followed by thermal treatment.•Crystallite sizes increase with increasing temperature of thermal treatment.•Photocatalytic activities are optimized for nanostructured hexagonal phases.•Photoluminescence emissions are optimized for monoclinic phases.•Crystallite dimensions condition photoluminescence and photocatalytic properties.