仿生木材结构钒酸铈的制备及光催化性能

Preparation and photocatalytic performance of biomimetic wood structure cerium vanadate

钒酸铈(CeVO_(4))在水污染处理领域被广泛关注,然而比表面积小、分散性差、光利用效率低等问题限制了其应用。本研究使用云杉模板,通过仿生合成法,制备出仿生木材结构的三维多孔钒酸铈光催化剂。通过降解模拟污染物伊红黄,讨论仿生木材结构钒酸铈的光催化性能。结合SEM/XRD/BET/XPS/DRS等表征分析,探究其光催化降解机理。结果表明:采用云杉模板合成的仿生木材结构钒酸铈具有类木材的多孔结构,比表面积是8.6910 m^(2)/g,平均晶粒尺寸为30.76 nm。相较于直接水热合成的钒酸铈,仿生木材结构钒酸铈的氧空位率提升了22%,其禁带宽度从2.96 eV减小到2.54 eV。在紫外光照射条件下对伊红黄的降解率为90%,在酸性条件下降解率可达95%,具有良好的循环稳定性。仿生木材结构钒酸铈降解有机污染物的性能优异,独特的类木材结构提升了钒酸铈的光能利用率,为其提供了更多的反应位点,有效地抑制了光生电子-空穴的复合,进一步提升了钒酸铈的光催化性能。本研究将木材的多孔结构与钒酸铈良好的光催化特性相结合,实现了林木加工剩余物的高值化利用。

Cerium vanadate(CeVO_(4)) has been widely utilized in the field of water pollution treatment, but its small specific surface area, poor dispersibility, and low light utilization efficiency have restricted its application. In this stu-dy, using spruce template, the cerium vanadate precursor was loaded on the spruce through the biomimetic synthesis method of impregnation-hydrothermal-roasting, and finally cerium vanadate nanoparticles with a bionic wood structure were generated, and the wood structure was used to improve its performance. By degrading the simulated pollutant eosin yellow, the photocatalytic performance of the biomimetic wood structure cerium vanadate was discussed. Combined with the scanning electron microscopy(SEM), X-ray diffraction(XRD), BET specific surface area measurement method, X-ray photoelectron spectroscopy(XPS), ultraviolet diffuse reflectance(DRS) and other analyses, the photocatalytic degradation mechanism was explored. The results showed that the biomimetic wood structure cerium vanadate synthesized with spruce template had a wood-like porous structure, with a specific surface area of 8.691 0 m^(2)/g and an average grain size of 30.76 nm. Compared with the direct hydrothermal synthesis of cerium vanadate, the oxygen vacancy rate of the bionic wood structure cerium vanadate was increased by 22%, and its band gap was reduced from 2.96 to 2.54 eV. Using 20 mg/L eosin yellow aqueous solution as the target degradation pollutant, after 180 minutes of ultraviolet mercury lamp irradiation, the photocatalytic effect of biomimetic wood structure cerium vanadate was the most obvious, and the degradation rate of eosin yellow reached 90%. Under these conditions, the degradation rate can reach 95%. It had good cycle stability. The biomimetic wood structure of cerium vanadate had a good performance in degrading organic pollutants. Its unique wood-like structure improved the absorption and utilization of light by cerium vanadate, effectively reduced the band gap width and the oxygen vacancy content was increased from 50% to 72%, providing more reaction sites, effectively inhibiting photo-generated electron holes, and further improving the photocatalytic performance of cerium vanadate. This research combined the porous structure of wood with the good photocatalytic properties of cerium vanadate to realize the high-value utilization of wood processing residues.