Promoted photo-oxidation reactivity of particulate BiVO4 photocatalyst prepared by a photoassisted sol-gel method
Promoted photo-oxidation reactivity of particulate BiVO4 photocatalyst prepared by a photoassisted sol-gel method
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DOI：
10.1149/1.2051868
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发表时间：
2005-01-01
影响因子：
3.9
通讯作者：
Nakato, Y
中科院分区：
文献类型：
--
作者：
Liu, HM;Nakamura, R;Nakato, Y
采用光助溶胶-凝胶法合成了具有白钨矿-单斜晶系（s-m）结构的钒酸铋（BiVO 4）粉体，改进的溶胶-凝胶法，包括一个额外的步骤，其中BiCl 3、VO（OC 3 H7）（3）和异丙醇钠的混合溶液在水解之前用紫外光照射。光辅助溶胶-凝胶法制备的BiVO 4粉末（称为P样品）的光析氧活性是传统非光辅助溶胶-凝胶法制备的BiVO 4粉末（称为N样品）的1.3-3倍，表明光辅助溶胶-凝胶法可有效提高BiVO 4的光催化活性。X射线衍射图和紫外-可见吸收光谱在P-和N-样品之间是相同的，而SEM检查表明，P-样品由分离良好的小尺寸颗粒组成，与N-样品相比。X射线光电子能谱检测还表明，P-样品具有含有Bi 5+和OH-的薄表面层。讨论了P样品的高活性是由于BiVO_4颗粒尺寸小或含有Bi ~（5+）和OH ~-的表面层具有一定的催化作用。(c)2005年电化学学会。All rights reserved.
Bismuth vanadate (BiVO4) powder with a scheelite-monoclinic (s-m) structure was synthesized by a photoassisted sol-gel method, i.e., a modified sol-gel method including an additional procedure in which a mixed solution of BiCl3, VO(OC3H7)(3), and sodium isopropoxide was irradiated with UV light before hydrolysis. The BiVO4 powder prepared by the photoassisted sol-gel method (called P-sample) exhibited 1.3-3 times higher activity in oxygen photoevolution reaction than that prepared by the conventional nonphotoassisted sol-gel method (called N-sample), indicating that the photoassisted sol-gel method is effective for improving the photocatalytic activity of BiVO4. X-ray diffraction patterns and UV-visible absorption spectra were the same between the P- and N-samples, whereas SEM inspection showed that the P-sample was composed of well-separated small-size particles, compared with the N-sample. X-ray photoelectron spectroscopy inspection also exhibited that the P-sample had a thin surface layer containing Bi5+ and OH-. It is discussed that the high activity of the P-sample is attributed either to the small size of BiVO4 particles or a certain catalytic action of the surface layer containing Bi5+ and OH-. (c) 2005 The Electrochemical Society. All rights reserved.