Gallium zinc oxy nitrides are promising new materials for photocatalytic applications due to their lower band gap compared to other commonly used photocatalysts. These materials are synthesized by nitridation of Ga2O3 and ZnO mixtures at temperatures between 550oC and 850oC under NH3 flow. The product obtained is a solid solution of GaN and ZnO, as confirmed by x-ray diffraction. X-ray photoelectron spectroscopy confirmed the substitution of oxygen atoms for nitrogen atoms and the presence of Zn-N bonds on the surface. The optical band gap of the samples is between 2.6 to 2.8 ev based on UV/Vis spectra, lower than that either GaN (3.4 ev) or ZnO (3.2 ev), permitting the generation of electron-hole pairs using visible light. The selective oxidation of organic compounds such as acetaldehyde using the photocatalyst is being investigated. The effect of nitridation temperature on the crystal morphology and the BET surface areas will be analyzed and correlated with the rates of oxidation & activities. The results will then be compared to anatase TiO2 and ZnO. Thus, by adjusting the nitridation temperature it may be possible to obtain a material with optimum properties for the oxidation reaction.