Zou Lianli, Jing Maoxiang, Xiang Jun, Wang Pan, Shen Xiangqian
J Nanosci Nanotechnol. 2014 Mar;14(3):2446-50. doi: 10.1166/jnn.2014.8503.
The nanocrystalline, honeycomb-like, perovskite LaFeO3 microfibers with a fibre diameter about 1-2 microm and channel sizes about 180-220 nm on the cross-section were prepared by the citrate-gel process. These microfibers were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and Brunauere-Emmette-Teller (BET) method. After calcined at a low temperature of 550 degrees C for 6 hours, the single phase of perovskite LaFeO3 microfibers is formed and the grain size increases from 27 to 38 nm with the calcination temperature increasing from 500 to 650 degrees C. The catalytic activity for soot combustion was analyzed by thermo-gravimetric method (TG), and the LaFeO3 microfibers calcined at 600 degrees C exhibits the highest catalytic activity for soot combustion, with a lowest T50 (393 degrees C) and T90 (434 degrees C). The formation mechanism of the honeycomb-like structure is analyzed and these honeycomb-like microfibers can be used as advanced catalysts, absorbents, filters and microreactors.
通过柠檬酸盐凝胶法制备了纤维直径约为1-2微米、横截面通道尺寸约为180-220纳米的纳米晶蜂窝状钙钛矿型LaFeO₃微纤维。这些微纤维通过X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）和布鲁瑙厄-埃米特-泰勒（BET）方法进行表征。在550℃低温下煅烧6小时后，形成了钙钛矿型LaFeO₃微纤维的单相，并且随着煅烧温度从500℃升高到650℃，晶粒尺寸从27纳米增加到38纳米。通过热重法（TG）分析了对碳烟燃烧的催化活性，在600℃煅烧的LaFeO₃微纤维对碳烟燃烧表现出最高的催化活性，最低T50（393℃）和T90（434℃）。分析了蜂窝状结构的形成机理，这些蜂窝状微纤维可用作先进的催化剂、吸附剂、过滤器和微反应器。
