The mechanisms of intrinsic luminescence in the set of molybdate crystals of M^IM^III(MoO₄)₂ (M^I = Li, Na, K; M^III =Bi, Y, Fe) type are revealed in complex experimental and theoretical studies. The luminescence spectroscopy under vacuum ultraviolet (VUV) synchrotron excitations is applied together with the electronic structure calculations carried out by the FLAPW method. The energy gaps (E_g) values of the crystals are determined in simultaneous analysis of diffuse reflectance and luminescence excitation spectra. It is found that the molybdate groups MoO₄^2- play a dominant role in the processes of intrinsic luminescence in studied molybdate compounds

The influence of Mo content in the solid solutions of Bi_1−x/3V_1−xMo_xO₄ (x = 0.05–0.20) on the morphology, band gap, structure and light-driven water oxidation properties has been studied by SEM, powder XRD and vibrational spectroscopy.