Novel photothermocatalytic synergetic effect leads to high catalytic activity and excellent durability of anatase TiO2 nanosheets with dominant {001} facets for benzene abatement
Novel photothermocatalytic synergetic effect leads to high catalytic activity and excellent durability of anatase TiO2 nanosheets with dominant {001} facets for benzene abatement
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DOI：
10.1016/j.apcatb.2016.05.073
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发表时间：
2016-12
影响因子：
22.1
通讯作者：
L. Ren;M. Mao;Yuanzhi Li;L. Lan;Zhen Zhang;Xiujian Zhao
中科院分区：
文献类型：
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作者：
L. Ren;M. Mao;Yuanzhi Li;L. Lan;Zhen Zhang;Xiujian Zhao
研究了反应温度对以{001}晶面为主的锐钛矿型纳米二氧化钛对难降解和致癌苯气相光催化氧化活性的影响。结果表明，随着反应温度从室温升高到240℃和290℃，TiO2纳米片的光催化活性显著提高。同时，当反应温度升高到240℃以上时，TiO2纳米片在黑暗中对苯有明显的热催化氧化作用。在汞灯照射下，240℃和290℃下的TiO2纳米片的光催化活性(CO2产率，rCO2-PTC)远远高于相同紫外光强度下的光催化活性(rCO2-PC)和黑暗中相同反应温度下的热催化活性(rCO2-TC)。这一结果表明，在二氧化钛纳米片上，光催化和热催化之间存在光热催化协同效应，从而显著提高了催化活性。以CO为探针分子的原位FTIR光谱进一步验证了光热催化的协同效应：光生电子和空穴产生的活性物种加速了二氧化钛纳米片上的热催化氧化，从而显著提高了催化活性。通过在汞灯表面涂覆纳米二氧化钛样品，在不增加加热器的情况下，利用紫外光和氦灯发出的红外光的加热效应，实现了苯的高效光热催化氧化。在这种光热催化条件下，二氧化钛纳米片的光热催化活性(rCO2-PTC)比常温下相同汞灯下的光催化活性(rCO2-pC)提高了42.3倍，并且表现出良好的耐苯氧化性能。
We studied the effect of reaction temperature on the photocatalytic activity of anatase TiO2nanosheets with dominant {001} facets for the gas-phase photocatalytic oxidation of recalcitrant and carcinogenic benzene. It is found that the photocatalytic activity of the TiO2nanosheets significantly enhances with increasing reaction temperature from room temperature to 240, and 290 °C. Meanwhile, obvious thermocatalytic oxidation of benzene is observed on the TiO2nanosheets in the dark when the reaction temperature increases above 240 °C. The photothermocatalytic activity (CO2production rate,rCO2-ptc) of the TiO2nanosheets at 240 or 290 °C under the irradiation of an Hg lamp is much higher than the summation of the photocatalytic activity (rCO2-pc) with the same UV light intensity at room temperature and thermocatalytic activity (rCO2-tc) at the same reaction temperature in the dark. This result indicates the presence of a photothermocatalytic synergetic effect between the photocatalysis and the thermocatalysis on the TiO2nanosheets, thus significantly increasing the catalytic activity. The photothermocatalytic synergetic effect is further verified by in-situ FTIR spectra with CO as probe molecule: active species produced by photogenerated electrons and holes accelerate the thermocatalytic oxidation on the TiO2nanosheets, thus significantly increasing the catalytic activity. Just by coating the sample of TiO2nanosheets on the surface of the Hg lamp, we realized highly efficient photothermocatalytic oxidation of benzene with utilizing UV light and heating effect of infrared light from the He lamp without using additional heater. Under such photothermocatalytic condition, the photothermocatalytic activity (rCO2-ptc) of the TiO2nanosheets increased by 42.3 times as compared to the photocatalytic activity (rCO2-pc) at room temperature with the same Hg lamp, and the TiO2nanosheets exhibit excellent durability for benzene oxidation.