The Effects of Starting Materials in the Synthesis of (Ga 1− x Zn x )(N 1− x O x ) Solid Solution on Its Photocatalytic Activity for Overall Water Splitting under Visible Light

It all depends on the ingredients : The physicochemical properties of (Ga 1− x Zn x )(N 1− x O x ), including its particle size, are dependent on the particle size of the ZnO precursor. The relationship between the physicochemical properties and photocatalytic performance of (Ga 1− x Zn x )(N 1− x O x ) for overall water splitting under visible light was investigated to identify suitable starting materials of the catalyst.The influence of starting materials on the physicochemical and photocatalytic properties of (Ga 1−x Zn x )(N 1−x O x ) were investigated in an attempt to optimize the preparation conditions. The catalyst was successfully prepared by nitriding a starting mixture of ZnO and Ga 2 O 3 . A mixture of metallic zinc and GaN, however, did not afford the desired compound. The crystallinity, surface area, composition, and absorption characteristics of the resultant (Ga 1−x Zn x )(N 1−x O x ) solid solution are found to be dependent on the morphology of ZnO but largely insensitive to the choice of Ga 2 O 3 polymorph. The use of coarser‐grained ZnO results in a coarser‐grained catalyst with elevated zinc and oxygen content and reduced uniformity in composition and crystallinity. The results demonstrate the importance of selecting appropriate ZnO and Ga 2 O 3 starting materials for maximizing the photocatalytic activity of (Ga 1−x Zn x )(N 1−x O x ) for overall water splitting under visible light.