A new photo- Fenton catalyst has been manufactured from synthetic layered clay laponite (Laponite RD) by the pillaring technique. Eight different catalyst samples were prepared: four without thermal aging (WTA) calcined at 523 K, 623 K, 723 K and 823 K, and other four with thermal aging (TA) calcined at the same temperatures. The samples have been characterized by XRD and SEM/ EDS techniques, and through the bulk chemical analysis. The results of this characterization have been previously reported [8]. This paper presents the results regarding the activity of the catalyst samples, determined for the phenol degradation in water by the photo- Fenton process, using an aqueous solution of 0.1 mM concentration in the presence of 5mM H2O2, 1g/L catalyst, pH3, and 303 K. The activity of each catalyst sample was evaluated through the apparent first order rate constant derived from the experimental kinetic curves, representing the phenol conversion (XPh) versus reaction time.The best results were obtained with the TA- 623 catalyst.