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在Pt/TiO2存在下,研究了光催化降解对氟苯甲酸的反应.考察了反应时间、溶液初始pH值以及污染物初始浓度对光催化反应的影响.结果表明,溶液的紫外吸光度值随反应时间不断下降;反应7 h时,溶液的TOC去除率达23.2%;反应0.5～2 h内,氟离子平均生成速率为3.53×10-5mol.L-1.h-1;在反应3～7 h内,氟离子平均生成速率为6.22×10-5mol.L-1.h-1.在溶液初始pH值=3.34～3.72时,氟离子生成速率最大,在碱性范围内,氟离子的生成速率为零.当C0(p-fluorobenzoic acid)<1.80×10-3mol.L-1时,光催化降解生成氟离子的速率随着对氟苯甲酸浓度的增大而增大;当C0(p-fluorobenzoic acid)>2.00×10-3mol.L-1时,光催化降解生成氟离子的速率不再随污染物浓度的变化而发生变化.探讨了可能的反应机理.
The photocatalytic degradation of fluorobenzoic acid was studied in the presence of Pt / TiO2. The effects of reaction time, initial pH of the solution and the initial concentration of the pollutants on the photocatalytic reaction were investigated. The results showed that the UV absorbance of the solution varied with the reaction The reaction time 7 h, the solution of TOC removal rate of 23.2%; reaction 0.5 ~ 2 h, fluoride ion average generation rate of 3.53 × 10-5mol.L-1.h-1; in the reaction 3 to 7 The average rate of formation of fluoride ions was 6.22 × 10-5mol.L-1.h-1. The initial fluoride ion formation rate was the highest at the initial pH value of 3.34 ~ 3.72. In the basic range, the fluoride ion formation rate The rate is zero.When the C0 (p-fluorobenzoic acid) is less than 1.80 × 10-3mol.L-1, the rate of photocatalytic degradation of fluoride ions increases with the concentration of p-fluorobenzoic acid.When C0 (p -fluorobenzoic acid> 2.00 × 10-3mol.L-1, the rate of photocatalytic degradation of fluoride ions no longer changes with the concentration of pollutants change.Researches of the possible reaction mechanism.