CaTiO3 as one of the perovskite-based photocatalysts has a band gap energy of 3.5 eV (~354 nm), thus will work at the ultraviolet light region. One of the strategies to decrease the band gap energy is doping metal. In this research, CaTiO3 was doped by Fe element as purposes to decreasing its band gap energy. Fe doped CaTiO3 compounds were synthesized using molten NaCl salt method. The diffractogram samples showed that the Fe-doped CaTiO3 crystal was successfully prepared. Meanwhile, the SEM images showed that the particle shape was regular polyhedral morphology, and doping Fe3+ caused the particle size to decrease and agglomerated. The UV-Vis DRS spectra showed that the Fe-dopant revealed the absorption light at visible range wavelength.

SrTiO3 is a material with perovskite-type structure which received many attentions because it has a wide potential in various fields such as piezoelectric and photocatalyst. The photocatalyst material of SrTiO3 have band gap energy 3.2 eV, as results it will work on wavelength 387.45 nm (ultraviolet light). Doping metal to SrTiO3 was reported to decrease its band gap energy. In this research, we synthesized iron-doped SrTiO3 (SrTix-1FexO3 (x= 0, 0.05, 0.1, 0.15, and 0.2)) using molten salt method. The diffractogram of SrTix-1FexO3 (x= 0, 0.05, 0.1, 0.15, and 0.2) showed that the samples goal were successfully synthesized, but still found impurities (TiO2 phase) at x= 0.2. The SEM images showed that the morphology of particles is cubic and there are found agglomeration in iron-doped SrTiO3. The UV-Vis DRS spectra showed that iron dopant can reveal the light absorption in visible wavelength region.