The suspended TiO2 powder enjoys free contact with pollutant molecule in a photocatalytic reactor; it can generally achieve better efficiency than the immobilized TiO2 catalysts. However, the separation and reuse of this catalyst powder from treated water often limit its application in practice. An adsorptive activated carbon-supported titanium dioxide photocatalyst TiO2/AC was prepared using nanosized titanium dioxide (anatase) immobilized on activated carbon powder by a novel preparation technique with polyacrylic ester emulsion. Meanwhile, the heterogeneous photocatalytic decomposition of aqueous hydroquinone over the ultraviolet irradiated TiO2/AC photocatalyst was carried out with high decomposition efficiencies in a slurry photocatalytic reactor (SPCR), which provided the effective contact of TiO2/AC photocatalyst and reactant. The pH value, the ratio of TiO2/hydroquinone, the aerating, and the concentration of H2O2 on photocatalytic decomposition of hydroquinone were discussed in detail. Experimental results showed that not only did the photocatalyst have a high adsorption performance and a good photocatalytic activity for hydroquinone but also the catalyst was easily separated from SPCR and recycled as well. Moreover, it was found that the reaction kinetic fixed the pseudo-first-order kinetic equation, which provided a detailed kinetic understanding of photocatalytic degradation of hydroquinone in SPCR.