PEG-Assisted Hydrothermal Synthesis and Photocatalytic Activity of Bi 2 Fe 4 O 9 Crystallites
- PDF / 234,466 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 83 Downloads / 269 Views
PEG-Assisted Hydrothermal Synthesis and Photocatalytic Activity of Bi2Fe4O9 Crystallites Dengrong Cai, Jianmin Li, Shundong Bu, Shengwen Yu, Dengren Jin and Jinrong Cheng* School of Materials Science and Engineering, Shanghai University, Shanghai, China Corresponding E-mail: [email protected] ABSTRACT A facile hydrothermal route assisted by polyethylene glycol (PEG) 400 was utilized to synthesize single-phase Bi2Fe4O9 crystallites. X-ray diffraction results showed the products with PEG 400 of 30 g/L exhibited a preferred growth along the (001) plane. Transmission electron microscopy indicated that the morphology of the as-prepared Bi2Fe4O9 crystallites with PEG 400 were plake-like and rod-like. Strong absorption in visible-light region of the products was characterized by UV-vis diffuse reflectance spectrum (UV-DRS). The photocatalytic activity of Bi2Fe4O9 crystallites was evaluated on degradation of methyl orange (MO) under visible light irradiation. For 3 h irradiation, the degradation ratio was increased to 93% with the aid of a small amount of H2O2. The analysis of FT-IR spectra proved that the Bi2Fe4O9 catalysts were remained stable after the photocalytic reactions. INTRODUCTION Semiconductor photocatalysis with a primary focus on TiO2 as a durable and nontoxic catalyst has been applied to environmental problems and energy crisis, such as water purification[1,2]. However, the wide bandgap of TiO2 (3.2 eV) limited its application in the visible light region. Therefore, it is of great scientific and technological interest to develop new photocatalysts that are able to respond to visible light irradiation [3-5]. Bi2Fe4O9 is a well-known material in Bi-Fe-O system, which crystallizes in the orthorhombic space group of Pbam. And a unit cell of Bi2Fe4O9 contains two formula units with FeO6 octahedral and FeO4 tetrahedral [6]. Potential applications of Bi2Fe4O9 such as gas sensors, magnetic and ferroelectric devices have been proposed because of electron coupling and magnetic property [7-9]. Bi2Fe4O9 has be utilized for catalytic oxidation of NH3 to NO, which make it possible to replace usual commercial catalysts such as platinum, rhodium, and palladium[10,11]. Recently, the photocatalysis of Bi2Fe4O9 is of great interest because it has a photoabsorption from UV light to visible light. Ruan et al. reported that about 80% of MO was removed after 24 h of visible light irradiation with Bi2Fe4O9 nanosheets, while the degradation ratio was only 3% when using Bi2Fe4O9 microplatelets as catalysts under the same conditions[12]. Sun and her coworkers synthesizd flowerlike Bi2Fe4O9 which exhibited much higher performance for oxidation of phenol and aqueous ammonia than that of bulk- Bi2Fe4O9 under visible light irradiation [13]. Therefore, the morphology of Bi2Fe4O9 plays an important role in photocatalytic performance. It is reported that the morphology and dispersity of inorganic materials can be controlled by organized organic surfactants. And various morphologies of nanomaterials have been synthesized by using PEG as
Data Loading...
