(1. 东北大学 材料与冶金学院,沈阳 110004;
2. 河北省廊坊市规划局,廊坊 065000)
摘 要: 利用高能球磨法制备了钙钛矿型硫酸盐掺杂的含钛高炉渣光催化剂,考察了初始pH值对Cr(Ⅵ)−柠檬酸−硝酸铁(Cr(Ⅵ)-CA-FN)复合体系中Cr(Ⅵ)吸附效率和光催化还原效率的影响,并探讨了Cr(Ⅵ)-CA-FN复合体系中Cr(Ⅵ)可能的光催化还原机理。结果表明:在Cr(Ⅵ)-CA-FN复合体系中,酸性条件下有利于Cr(Ⅵ)的光催化还原,最佳pH值为2.5;柠檬酸和Fe(Ⅲ)降低了吸附对Cr(Ⅵ)还原率的影响,有效地抑制电子−空穴对的复合,促进光生电子还原Cr(Ⅵ)离子;六价铬浓度的降低一部分是光催化还原所致,另一部分是由于催化剂本身含有的二价锰离子还原所致。
关键字: 含钛高炉渣;Cr(Ⅵ)−柠檬酸−硝酸铁复合体系;光催化还原;六价铬
Cr(Ⅵ) -citric acid-ferric nitrate compound system
(1. School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China;
2. Bureau of Urban Planning of Langfang, Langfang 065000, China)
Abstract:Using calcined sulfate-modified titanium-bearing blast furnace slag as photocatalyst, the photocatalytic reduction of Cr(Ⅵ) in Cr(Ⅵ) -citric acid-ferric nitrate compound systems were studied. The effects of pH values on the photocatalytic reduction and adsorption of Cr(Ⅵ) were investigated. The results indicate that the acidic solutions are favorable for the photocatalytic reduction of Cr (Ⅵ) in Cr(Ⅵ)-citric acid-ferric nitrate (Cr(Ⅵ)-CA-FN) compound system, and the optimum pH value for the reduction of Cr (Ⅵ) is 2.5. The effect of adsorption on the photocatalytic reduction of Cr(Ⅵ) decreases. The recombination rate of electron-hole pairs decreases, and hence the reduction efficiency of Cr(Ⅵ) enhances. The decline of Cr(Ⅵ) concentration is caused by the compound effect between the reduction of Mn2+ and the photocatalytic reduction.
Key words: titanium-bearing blast furnace slag; Cr(Ⅵ)-citric acid-ferric nitrate(Cr(Ⅵ)-CA-FN) compound system; potocatalytic reduction; Cr(Ⅵ)