Soft-Templated Sol–Gel Synthesis of Mesoporous Perovskite-Type Multicomponent Metal Oxide (Bi0.2Na0.2K0.2La0.2Sr0.2)TiO3and Its Enhanced Photocatalytic Activity

Abstract

The high calcination temperature required for the crystallization of multicomponent metal oxides is a challenge because this treatment significantly reduces their specific surface area while increasing the crystallite size, thereby limiting their photocatalytic performances. In this study, we have addressed this issue for a multicomponent perovskite photocatalyst, (Bi0.2Na0.2K0.2La0.2Sr0.2)TiO3 (BNKLST), by employing a soft-templating sol–gel method using Pluronic F-127. The synthesis process was optimized by adjusting the solution’s pH to ensure uniform micelle self-assembly and by determining the optimum calcination temperature for the pore formation. This approach enabled the successful low-temperature synthesis of BNKLST, which retained a high specific surface area of 50.4 m2 g–1 at 400 °C. The resulting catalyst exhibited excellent photocatalytic activity, degrading methylene blue under UV irradiation (250–450 nm) at a rate more than six times faster than that obtained using commercial SrTiO3. These findings demonstrate that enhancing the specific surface area of multicomponent metal oxides through a soft-templating approach is an effective strategy in photocatalyst design.