TiO2 has been used as a photocatalyst for decades. Owing to the close energy gap between zinc oxide (ZnO) and TiO2, and its high light transmittance and porosity, ZnO is also extensively used in photocatalytic processing [12]. Pozan et al. used ZnO and TiO2 as photocatalysts to degrade 4-chlorophenol. The experimental results found that if pure TiO2 or ZnO was used, only 64% and 75% degradation rate were observed, respectively, after 75 min of treatment [13]. However, the degradation rate significantly increased to 100% when 20 wt% ZnO/80 wt% TiO2 composite photocatalyst was applied. Several researchers have concluded that photocatalytic activity can be determined by reducing the probability of the charge carrier recombination rate by using the modified photocatalyst. In general, the photoelectric properties, light capturing ability, and photocatalytic ability of photocatalysts can be modified by using methods such as metal-doping, non-metal doping and co-doping to promote their photocatalytic activity [14–17].