Vol.:(0123456789) 1 3 Journal of Inorganic and Organometallic Polymers and Materials https://doi.org/10.1007/s10904-019-01259-0 Efect of pH on Phase, Morphology and Photocatalytic Properties of BiOBr Synthesized by Hydrothermal Method Prakasit Intaphong 1  · Anukorn Phuruangrat 1  · K. Karthik 2  · Phattranit Dumrongrojthanath 3  · Titipun Thongtem 4,5  · Somchai Thongtem 4,6 Received: 12 March 2019 / Accepted: 5 July 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Efect of pH on crystalline structure, morphology and visible-light-driven photocatalysis of BiOBr samples hydrothermally synthesized in solutions with the pH of 2–10 was investigated. The as-synthesized BiOBr samples investigated by X-ray dif- fraction, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. In this research, the as-synthesized samples are pure tetragonal BiOBr phase at the pH of 2–10, and were composed of microplates, nanoplates and hierarchical micro-fowers controlled by the solution pH. The as-synthesized sample at the pH 8 was revealed the presence of Bi 4f, O 1s and Br 3d. Visible-light-driven photocatalytic properties of the BiOBr photocatalyst with diferent morphologies were investigated through the photodeg- radation of rhodamine B (RhB). The BiOBr hierarchical micro-fowers synthesized in the solution with the pH 8 show the best photocatalytic activity for wastewater treatment and the · O 2 − radicals were attributed to be the primary active species for photodegradation of RhB under visible light irradiation. Keywords BiOBr hierarchical micro-fowers · Photocatalysis · Spectroscopy 1 Introduction The semiconductor photocatalysis as green technology is widely used for the degradation of harmful waste products such as dyes, insecticides, pesticides and toxic organic pol- lutants in wastewater to CO 2 , H 2 O and other small molecules at room temperature, including for splitting of water and production of hydrogen under light irradiation [1–5]. The widely used TiO 2 photocatalyst is active only under UV light irradiation (5% of solar radiation) because its band gap is 3.20 eV [2, 3, 6, 7]. Thus a number of researchers have done the research on visible-light-driven semiconductor photo- catalysts [2, 3, 8]. Visible-light-driven bismuth based semi- conductors such as BiVO 4 [1, 2], Bi 2 MoO 6 [3, 9], Bi 2 WO 6 [10–12], BiOX (X = Br, Cl and I) [13–18] are attractively interesting for wastewater treatment. Among them, bismuth oxide bromide (BiOBr) as ternary semiconductor materi- als with layered structure has an appropriate band gap of about 2.75 eV because it responds to visible-light and has outstanding chemical stability, leading it to be a promis- ing visible-light-driven photocatalytic candidate [19–21]. BiOBr as layered structure is built up by strong electrova- lent bond between [Bi 2 O 2 ] 2+ slab embedded in double slabs * Anukorn Phuruangrat phuruangrat@hotmail.com * Somchai Thongtem schthongtem@yahoo.com 1 Department of Materials Science and Technology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand 2 Department of Physics, Bharathidasan University, Tiruchirappalli, Tamil Nadu 620 024, India 3 Rajamangala University of Technology Lanna Chiang Rai, Chiang Rai 57120, Thailand 4 Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand 5 Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand 6 Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand