Vol.:(0123456789) 1 3 Topics in Catalysis https://doi.org/10.1007/s11244-020-01391-z ORIGINALPAPER Efect of Bismuth Dopant on the Photocatalytic Properties of SrTiO 3 Under Solar Irradiation Carlos Rodriguez Garcia 1  · Jorge Oliva 2  · David Chávez 1,3  · Briseida Esquivel 1  · Christian Gómez‑Solís 4  · Erika Martínez‑Sánchez 5  · Arturo Isaias Mtz‑Enriquez 6 Accepted: 9 October 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract This work presents the structural, morphological and photocatalytic properties of pure SrTiO 3 (STO) and Bismuth doped STO. Several Bi doped samples were synthesized using Bi concentrations from 0.5 to 5 mol% and the sol-gel method. According to the X-ray difraction analysis, all the samples presented cubic phase. The Scanning electron microscopy (SEM) showed that the samples without dopant or with low Bi concentration (0 and 0.5 mol%) presented a quasi-spherical morphol- ogy. The sample doped with 1 mol% of Bi presented mainly a rod-like morphology, while the samples doped with 2 and 5 mol% showed a mixture of quasi-cubic particles and rod-like particles. The absorbance experiments demonstrated that the introduction of Bi in the STO host extended the light absorption in the visible region and decreased the band gap of STO. Both efects benefted the photocatalytic properties of STO:Bi powders. In fact, the photocatalytic evaluation of the STO and STO:Bi powders under natural solar light revealed that total degradation of methylene blue (MB) can be produced only by the sample doped with 1 mol%. Scavenger experiments were also carried out using teraphtalic acid and benzoquinone in order to fgure out which oxidizing agent (OH· radicals or O 2 − ) is producing the degradation of MB dye and found that the OH· radicals are the dominant agent. Since the STO:Bi powders can be activated by solar light for the photocatalytic degradation of MB, these powders could be a low cost option for the degradation of dyes in water treatment plants. Keywords Solar photocatalysis · SrTiO 3  · Bismuth · Methylene blue · Degradation 1 Introduction The water pollution caused by the dyes disposed by the textile industry is currently causing health problems such as skin cancer and tumors in humans as well as mutagenic efect in plants [1–4]. Dyes are a group of complex organic materials that usually are poisonous; they are resistant to Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11244-020-01391-z) contains supplementary material, which is available to authorized users. * Carlos Rodriguez Garcia crodriguezgarcia@uadec.edu.mx * Jorge Oliva joliva@cio.mx 1 Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Coahuila, Prol. David Berlanga S/N Edif. A. unidad Camporedondo, 25000 Saltillo Coah, Mexico 2 Instituto Potosino de Investigación Científca y Tecnológica, Camino a la Presa de San José 2055, Lomas 4ta Secc, 78216 San Luis, S. L. P, Mexico 3 Programa de Posgrado de Doctorado en Ciencia y Tecnología de Materiales, Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Ing. J. Cárdenas Valdez S/N, República, 25280 Saltillo, Coahuila, Mexico 4 Depto. de Ingeniería Física, División de Ciencias e Ingeniería, Universidad de Guanajuato, Lomas del Bosque #103, Lomas del Campestre, 37150 León, Gto, Mexico 5 Facultad de Ingeniería, Universidad Autónoma de Coahuila, Ciudad Universitaria, Fundadores Km. 13, Las Glorias, 25350 Arteaga, Coahuila, Mexico 6 Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Unidad Saltillo, Industrial, Zona Industrial, 25900 Ramos Arizpe, Coahuila, Mexico