The inhibition effect of rare earths on the production of ·O - 2 produced by radiolysis of aqueous sodium formate saturated with O 2 with high energy pulse electron beam was studied. The result indicates ...The inhibition effect of rare earths on the production of ·O - 2 produced by radiolysis of aqueous sodium formate saturated with O 2 with high energy pulse electron beam was studied. The result indicates that rare earth nitrate obviously inhibits the production of ·O - 2 . The inhibition rate is between 28 6% and 92%. The inhibition effect increases with the increase of rare earth nitrates concentration. The distinguish dose effect relationship was observed.展开更多
The mechanism of cerium ions scavenging superoxide radical(O÷2) has been studied. The results show that (1) Ce^3+ can reduce O÷2 to H_2O_2 while it is oxidized to Ce^4+; (2) Ce^4+ can oxidize O÷2 to O_2...The mechanism of cerium ions scavenging superoxide radical(O÷2) has been studied. The results show that (1) Ce^3+ can reduce O÷2 to H_2O_2 while it is oxidized to Ce^4+; (2) Ce^4+ can oxidize O÷2 to O_2 while it is reduced to Ce^3+.展开更多
Nano cerium oxides are efficient photocatalysts for pollutants degradation with highly dispersed Ce（III） ions as the suggested active species to promote the reaction, while Ce（IV） species do not behave as a cataly...Nano cerium oxides are efficient photocatalysts for pollutants degradation with highly dispersed Ce（III） ions as the suggested active species to promote the reaction, while Ce（IV） species do not behave as a catalyst. In this paper, to understand the mechanism of Ce-based photocatalysts, we studied the comparison of simple cerium ions, Ce（III） and Ce（IV） in aqueous solution for organic pollutants degradation under UV irradiation. Orange II（AOII）, methyl orange, and p-nitrophenol were selected as the target pollutants. The formation and contribution of reactive oxygen species, the kinetics of Ce（IV） photoreduction and Ce（III） photooxidation, and the influence of solution p H were investigated in detail. It was found that at low p H Ce（IV） ions showed a higher activity for hydroxyl radicals production and AOII degradation than Ce（III） ions, which could be attributed to its fast reduction rate to Ce（III）. However, its activity dramatically decreased when solution p H increased, and was also strongly influenced by the type of pollutants; while Ce（III） exhibited high degradation efficiency of all the tested pollutants over a wide pH range.展开更多
文摘The inhibition effect of rare earths on the production of ·O - 2 produced by radiolysis of aqueous sodium formate saturated with O 2 with high energy pulse electron beam was studied. The result indicates that rare earth nitrate obviously inhibits the production of ·O - 2 . The inhibition rate is between 28 6% and 92%. The inhibition effect increases with the increase of rare earth nitrates concentration. The distinguish dose effect relationship was observed.
文摘The mechanism of cerium ions scavenging superoxide radical(O÷2) has been studied. The results show that (1) Ce^3+ can reduce O÷2 to H_2O_2 while it is oxidized to Ce^4+; (2) Ce^4+ can oxidize O÷2 to O_2 while it is reduced to Ce^3+.
基金Project supported by the National Natural Science Foundation of China(21304072,21207105)
文摘Nano cerium oxides are efficient photocatalysts for pollutants degradation with highly dispersed Ce（III） ions as the suggested active species to promote the reaction, while Ce（IV） species do not behave as a catalyst. In this paper, to understand the mechanism of Ce-based photocatalysts, we studied the comparison of simple cerium ions, Ce（III） and Ce（IV） in aqueous solution for organic pollutants degradation under UV irradiation. Orange II（AOII）, methyl orange, and p-nitrophenol were selected as the target pollutants. The formation and contribution of reactive oxygen species, the kinetics of Ce（IV） photoreduction and Ce（III） photooxidation, and the influence of solution p H were investigated in detail. It was found that at low p H Ce（IV） ions showed a higher activity for hydroxyl radicals production and AOII degradation than Ce（III） ions, which could be attributed to its fast reduction rate to Ce（III）. However, its activity dramatically decreased when solution p H increased, and was also strongly influenced by the type of pollutants; while Ce（III） exhibited high degradation efficiency of all the tested pollutants over a wide pH range.
