Ilka Mahdi, Bera Susanta, Kwon Se-Hun
School of Materials Science and Engineering, Pusan National University, Busan 46241, Korea.
Global Frontier R&D Center for Hybrid Interface Materials, Pusan National University, Busan 46241, Korea.
Materials (Basel). 2018 May 28;11(6):904. doi: 10.3390/ma11060904.
We report the successful synthesis of surface defective small size (SS) SnO₂ nanoparticles (NPs) by adopting a low temperature surfactant free solution method. The structural properties of the NPs were analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The presence of surface defects, especially oxygen vacancies, in the sample were characterized using micro-Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and photoluminescence emission. The Brunauer⁻Emmet⁻Teller (BET) nitrogen adsorption⁻desorption isotherms demonstrated the superior textural properties (high surface area and uniform pore size) of SS SnO₂ compared to large size (LS) SnO₂. A comparable study was drawn between SS SnO₂ and LS SnO₂ NPs and a significant decrease in the concentration of surface defects was observed for the LS sample. The results showed that surface defects significantly depend upon the size of the NPs. The surface defects formed within the band gap energy level of SnO₂ significantly participated in the recombination process of photogenerated charge carriers, improving photochemical properties. Moreover, the SS SnO₂ showed superior photoelectrochemical (PEC) and photocatalytic activities compared to the LS SnO₂. The presence of a comparatively large number of surface defects due to its high surface area may enhance the photochemical activity by reducing the recombination rate of the photogenerated charges.
我们报道了采用低温无表面活性剂溶液法成功合成表面有缺陷的小尺寸（SS）二氧化锡纳米颗粒（NPs）。使用X射线衍射（XRD）、场发射扫描电子显微镜（FESEM）和透射电子显微镜（TEM）分析了纳米颗粒的结构特性。使用显微拉曼光谱、X射线光电子能谱（XPS）和光致发光发射对样品中表面缺陷（尤其是氧空位）的存在进行了表征。布鲁瑙尔-埃米特-泰勒（BET）氮吸附-脱附等温线表明，与大尺寸（LS）二氧化锡相比，SS二氧化锡具有优异的结构特性（高比表面积和均匀孔径）。对SS二氧化锡和LS二氧化锡纳米颗粒进行了对比研究，观察到LS样品的表面缺陷浓度显著降低。结果表明，表面缺陷显著取决于纳米颗粒的尺寸。在二氧化锡带隙能级内形成的表面缺陷显著参与了光生电荷载流子的复合过程，改善了光化学性质。此外，与LS二氧化锡相比，SS二氧化锡表现出优异的光电化学（PEC）和光催化活性。由于其高比表面积而存在的相对大量表面缺陷可能通过降低光生电荷的复合率来提高光化学活性。
