RESEARCH PAPER Rapid adsorption properties of flower-like BiOI nanoplates synthesized via a simple EG-assisted solvothermal process Bin Zhang • Guangbin Ji • M. A. Gondal • Yousong Liu • Xingmiao Zhang • Xiaofeng Chang • Nianwu Li Received: 21 January 2013 / Accepted: 2 June 2013 / Published online: 13 June 2013 Ó Springer Science+Business Media Dordrecht 2013 Abstract Uniform well-crystallized flower-like BiOI nanoplates contained 3.7 nm mesopores, which may be attributed to the internanosheet spaces of BiOI with maximum pore diameters of about 30 nm, were successfully synthesized via a simple ethylene glycol- assisted solvothermal method. The as-prepared porous BiOI nanoplates exhibited excellent adsorption ability, and the saturated extent of adsorption of BiOI over an RhB solution was as high as 197 mg/g, which is much higher than those for BiOCl and BiOBr prepared via the same method and with a similar surface area. The probable adsorption mechanism could have originated from the interaction between the I atom in BiOI and a proton in RhB at different pH values and temperatures. With visible light irradiation (k [ 420 nm), 80 % of the RhB was degraded in 4 h, while BiOI still demonstrated reasonably outstanding photocatalytic ability under green light (k = 550 ± 15 nm) because of its low-energy gap (1.72 eV). The degradation test for BiOI under irradiation at k = 550 ± 15 nm is an excellent achievement for field applications because the catalyst can be applied in solar irradiation to remove organic pollutants, which may be of great value BiOI complex. Keywords BiOI  Nanoplates  Adsorption  Visible light irradiation  Solvothermal process Introduction Bi-based compounds are considered as important photocatalysts because of their special layer structure, suitable energy gap, and environment-friendly nature (Wu et al. 2007; Zhang et al. 2012; Wang et al. 2012). Among these compounds, oxidation of bismuth hal- ogens (BiOX (X = Cl, Br, I)) has been reported as excellent candidates because of their photocatalytic properties under visible light. The band gap of BiOX (Cl, Br, I) has been estimated to be between 3.19 and 3.44 eV (Shenawi-Khalil et al. 2012a; Chang et al. 2012), 2.64 and 2.91 eV (Shenawi-Khalil et al. 2012b; Gondal et al. 2011), and 1.77 and 1.92 eV (Luz and Feldmann 2011), respectively. BiOX has a narrow energy gap (E g ) and a high-photocatalytic activity, thereby giving it higher visible light response and utilization rate of sunlight, particularly in the visible region. An increasing number of studies have focused on the outstanding photocatalytic actions of BiOX for environmental remediation. B. Zhang  G. Ji (&)  Y. Liu  X. Zhang  X. Chang  N. Li College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People’s Republic of China e-mail: gbji@nuaa.edu.cn M. A. Gondal Physics Department, King Fahd University of Petroleum and Minerals, Mail Box 5047, Dhahran 31261, Saudi Arabia 123 J Nanopart Res (2013) 15:1773 DOI 10.1007/s11051-013-1773-4