We prepared nanoparticles of a microporous Pt catalyst over TiO2 (PtxT, x= 0.2–0.8 wt. %) with exposed (001) facets by sol-gel followed by spray-drying of a Ti(oBu)4-C2H6O and H2PtCl6-H2O mixture. The characterization methods were XRD, FTIR, BET, SEM-EDX/TEM, UV-DRS, Photoluminescence (PL) and Raman spectroscopy. XRD analysis confirmed that all samples consisted of mainly anatase with little rutile, while pure TiO2 (T) consisted of only anatase after calcination at 550° C. The deposition of Ptx on TiO2 produces tensile strain for x < 0.8 wt.%, while further increase causes compressive strain. The absorption wavelength of Ptx-TiO2 shifted to greater values compared to control T (UV–vis DRS spectroscopy). The PtxT powders exhibited lower PL intensity than T, since the addition of Pt nanoparticles up to 0.8% captures the photogenerated electrons. The broadening of the Raman peak and the small frequency shift for the Raman bands (1-Eg and B1g) indicate that there are oxygen vacancies and crystal lattice distortions. The degradation of 4-chlorophenol under UV and visible light was the model reaction for the photocatalytic activity. Radical scavenging experiments demonstrated that superoxide (O2−) anions followed by photogenerated h+ species are mainly responsible for the degradation of 4-chlorophenol. The PtxT samples degrade up to 40% more 4-chlorophenol under UV and Vis irradiation than Degussa P25 and T as a consequence of the high crystallinity, homogenous distribution of Pt, as well as surface area >300 m2/g and spherical morphology. Based on the data, we propose a photocatalytic mechanism.