Photocatalytic removal of elemental mercury on TiO2-BiOIO3 heterostructures: Mercury transformation, sulfur tolerance and SO2/SO3 conversion
Photocatalytic removal of elemental mercury on TiO2-BiOIO3 heterostructures: Mercury transformation, sulfur tolerance and SO2/SO3 conversion
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DOI：
10.1016/j.cej.2020.124390
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发表时间：
2020-05
影响因子：
15.1
通讯作者：
Tao Wang;Shangfei He;Yongsheng Zhang;Jiawei Wang;W. Pan
中科院分区：
文献类型：
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作者：
Tao Wang;Shangfei He;Yongsheng Zhang;Jiawei Wang;W. Pan
制备了tio2 - bioio3异质结构，研究了其光催化除汞、耐硫性能和紫外照射下SO2/ so3转化率。tio2 - bioio3具有优异的光催化性能，对hg0的吸附和氧化效率分别为58.5%和36.5%。so2对单质汞的去除有负面影响，随着H2O含量的增加，hg0和so2的氧化效率也受到抑制。bioio3的导带从TiO2的导带中捕获电子，电子将预吸附的氧还原为超氧自由基（dotO2−），有效氧化Hg2+和SO2，生成的Hg2+和so3重新扩散到气体中。在H2O存在下，光生电子从bioio3的导带流向TiO2的价带，I3−/I−作为电子传递介质，阻止了电子与空穴的复合（h+），聚集的h+与H2O反应形成羟基自由基（自由基dotOH），是氧化位点以外的氧化物质。
TiO2-BiOIO3heterostructures were prepared to study the photocatalytic removal of elemental mercury, sulphur tolerance and SO2/SO3conversion under UV irradiation. TiO2-BiOIO3produced excellent photocatalytic performance with highest Hg0adsorption and oxidation efficiencies of 58.5% and 36.5%. SO2exhibited a negative effect on elemental mercury removal, and the oxidation efficiency of Hg0and SO2were also inhibited as H2O content increased. The conduction band of BiOIO3trapped electrons from that of TiO2, the electrons reduced pre-adsorbed oxygen to superoxide radicals (radical dotO2−), which efficiently oxidize Hg0and SO2, the generated Hg2+and SO3re-diffused into the gas. In the presence of H2O, photogenerated electrons flowed from the conduction band of BiOIO3to the valence band of TiO2, I3−/I−acted as an electron transfer medium and prevented recombination of electrons and holes (h+), the gathered h+reacted with H2O to form hydroxyl radicals (radical dotOH), which is oxidative species other than the oxidative site.