花状Pt/Bi2WO6微米晶合成、表征及其高可见光催化性能

Synthesis, characterization of flower-like Pt/Bi2WO6 microcrystals and their high visible lightphotocatalytic performance

  • 摘要: 利用水热-光化学沉积法合成了一系列粒径为1.5~2 μm的花状Pt/Bi2WO6微米晶..利用X射线衍射仪(XRD)、N2物理吸附、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外可见漫反射光谱(DRS)、X射线光电子能谱(XPS)和傅里叶变换红外光谱(FT-IR)等手段进行表征..在可见光照射下(λ>420nm),进行了光催化降解染料酸性橙Ⅱ的性能测试.表征和测试结果表明,这些多尺度花状Pt/Bi2WO6复合微米晶,在水溶液中进行光催化降解反应具有优越的性能.此外,沉积1%的Pt纳米粒子可使光催化活性显著提高,为Bi2WO6的2.8倍.沉积的Pt纳米粒子由于产生表面等离子体的共振吸收,增强了对可见光的吸收能力,同时降低了光生电子(e-)和空穴(h+)的复合,促进了•OH自由基的产生,因此能在很大程度上提高了光催化活性.此外,这种特殊结构的Pt/Bi2WO6微米晶有利于在水溶液中进行分离和回收,提高了催化剂的利用效率.

     

    Abstract: A series of 1.5~2 μm Pt/Bi2WO6 composite microflowers were synthesized by a hydrothermal synthesis combination with photo-deposition method. The as-synthesized microflowers were characterized by powder X-ray diffraction (XRD), N2-physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR).The photocatalytic performance of the catalysts was evaluated by the consecutive photocatalytic degradation of acid orange II dye under visible light (λ > 420 nm) irradiation. The results showed that these hierarchical Pt/Bi2WO6 composite microflowers have superior texture property in aqueous photocatalytic reactions. Moreover, the deposition of optimal amount of 1% Pt brings about 2.8 times increase in activity. The deposited Pt NPs over Bi2WO6 nanosquares enhance the visible light absorption due to the surface plasmon resonance absorption, decrease the recombination rate of e-/h+ pairs and promote ·OH radicals production, hence largely boosting the photocatalytic activity. Moreover, the unique hierarchical structures of Pt/Bi2WO6 microflowers benefit their separation and recycle in aqueous photocatalytic reactions, and utilization efficiency of the catalyst has been improved.

     

/

返回文章
返回