High surface area BaZrO3 photocatalyst prepared by base-hot-water treatment

Barium zirconate (BaZrO3) nanoparticles have been prepared by modified sol–gel route. Low temperature process of base-hot-water treatment (BHWT) was conducted to obtain high surface area BaZrO3. The treatments were carried out at 90 °C and at pH 14 with various concentrations of NaOH solution. Single phase nanocrystalline perovskite structure of BaZrO3 powders was successfully obtained by immersing the BaZrO3 precursor into hot-basic condition of 1 M NaOH solution for 1 h and consecutively calcined at 1000 °C for 2 h. BaZrO3 powders with BHWT showed surface area of 18.4 m2/g which is nearly 8 times larger than those of the powders without BHWT. Photocatalytic activities of BaZrO3 powders upon bleaching of methylene blue in an aqueous solution under UV light irradiation were enhanced by the increment of their surface area.