烧绿石结构La2Ti2-xCoxO7的制备及可见光分解水性能

采用溶胶-凝胶法制备了烧绿石结构的光催化剂La2Ti2-xCoxO7 (x=0, 0.05, 0.10, 0.20), 通过XRD、FT-IR、BET、UV-Vis漫反射光谱等测试手段对催化剂的晶体结构、比表面积以及漫反射光谱进行了表征, 采用光催化反应装置和气相色谱仪对产氢速率进行了测定.研究结果表明, La2Ti2O7只在紫外光下有吸收, 而Co对La2Ti2O7的B位掺杂能使其在可见光区有明显的吸收; La2Ti2O7的Co掺杂不仅提高了其在紫外光照射下分解水制氢的能力, 而且可使其在可见光照射下分解水制氢; 在La2Ti2-xCoxO7(x=0-0.20)系列中, La2Ti1.9Co0.1O7分解水制氢能力最强.

Synthesis and Photocatalytic Decomposition of Water under Visible Light Irradiation of La2Ti2-xCoxO7 with Pyrochlore Structure

Photocatalysts La_2Ti_(2-x)Co_xO_7(x=0, 0.05, 0.10, 0.20) with pyrochlore structure were synthesized by sol-gel method. XRD, FT-IR, BET, and UV-Vis diffuse reflectance spectroscopy were used to characterize the crystal structure, specific surface area, and diffuse reflectance spectra, respectively, the formation rate of hydrogen was measured by the photocatalytic activity measurement device and gas chromatography(GC). The results indicated that the absorption pattern of La_2Ti_2O_7 was only generated in the ultraviolet region but La_2Ti_2O_7 with Co doping at B site had strong photoabsorption in the visible light region. The evolution rate of H_2 in photolysis of H_2O by the La_2Ti_(2-x)Co_xO_7 photocatalysts which doped with Co at B site was highter than that of undoped La_2Ti_2O_7. La_2Ti_(1.9)Co_(0.1)O_7 showed the best photocatalyst property in all photocatalysts of La_2Ti_(2-x)Co_xO_7 (x=0-0.20).