A facile preparation of ZnGa2O4 photonic crystals with enhanced light absorption and photocatalytic activity

Abstract

Photonic crystals of multiple metal oxides with highly ordered structures and unique photonic effects have presented a prospective application in designing of photocatalysts. In this study, a facile method was developed to prepare pure ZnGa₂O₄ photonic crystals with a highly ordered skeleton structure at a relatively low temperature (500 °C). Due to facilitated mass transport in a highly ordered channel, the as-prepared ZnGa₂O₄ photonic crystals exhibits better photocatalytic activity towards methyl orange degradation compared to those of porous ZnGa₂O₄ and ZnGa₂O₄ nanocrystals. By changing the pore diameters in the structure, a slow photon effect on the blue edge of photonic band gap could be observed, which consequently enhanced the electronic band absorption over ZnGa₂O₄ photonic crystals with a pore diameter of 180 nm, and further improved their corresponding photocatalytic activity. Furthermore, the degradation mechanism over ZnGa₂O₄ photonic crystals was discussed. The preparation of ZnGa₂O₄ photonic crystals in this study provides experimental guidance for developing ternary metal oxide photonic crystals with enhanced light absorption and photocatalytic activities.