Two novel dilacunary γ‐Keggin‐type germanotungstates with difunctional photocatalytic and anti-tumor properties

•The synthesized dilacunary γ‐Keggin‐type germanotungstates showed enhanced performance in both the dye degradation and anticancer experiments.•This work suggests that pH plays an important role in activating •OH radicals for dye degradation.•The effectiveness of compounds can also be extrapolated to the anticancer arena due to the preferential killing of cancer cells over normal cells, which ultimately contribute to developments into a ready-to-use anticancer agent in the future.•The structure-activity relationships of compounds indicate that the H-bonding interactions may influence the anti-tumor activity.