Effects of solution pH and processing cycle on nanostructured La2(MoO4)3 produced by cyclic microwave radiation

La2(MoO4)3 with different morphologies were successfully produced by a facile cyclic microwave radiation (CMR) processing of a 2:3 molar ratio lanthanum to molybdenum of La(NO3)3·6H2O and (NH4)6Mo7O24·4H2O in the solutions with different pH values adjusted by 2 M NaOH for different processing cycles. XRD, SEM, TEM, HRTEM and SAED showed that La2(MoO4)3 microflowers of nanoflake-like petals could be produced by a 180 W CMR for 15 cycles in the solutions with the pH 7 and 8. The 904 and 887 cm−1 Raman symmetric stretching modes as well as the 320 cm−1 asymmetric bending modes were detected, and direct energy gaps of the UV–visible spectroscopy were 3.47 and 3.85 eV, respectively. The formation mechanism was also proposed in relation to the experimental results.