Double perovskite oxide Ba

2

MgWO

6

was synthesized by semi-wet method using barium nitrate

ammonium molybdate and magnesium nitrate as raw materials. Photocatalyst NiO/Ba

2

MgWO

6

was prepared by equal volume impregnation method. The precursor was analysed by TG-DTA and the calcined sample was characterized by XRD and SEM. The effect of pH in precursor preparation on photocatalytic activity of the sample was investigated

and the effects of the second calcination on performances of the sample were examined. The results show that the prepared samples have best photocatalytic activity at pH=8

the purity and crystal perfection of the sample are improved by the second calcination at 1 100 ℃ for 6 h

and the hydrogen production rate of the c

atalyst increases from 1.2 μmol/h to 1.5 μmol/h.