A novel Keggin-based hybrid with left- and right-handed helical chains was obtained. The molybdophosphate-modified helical chain was rarely observed in POM-based complexes. The polypyrrole composite of 1 (PPy/1) was prepared by in situ polymerization process. PPy/1 shows photocatalysis for the degradation of MB and RhB under visible irradiation.