Photocatalytic Reactors. 3. Kinetics of the Decomposition of Chloroform Including Absorbed Radiation Effects
Photocatalytic Reactors. 3. Kinetics of the Decomposition of Chloroform Including Absorbed Radiation Effects
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光催化反应器。
DOI：
10.1021/es950806c
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发表时间：
1996
影响因子：
11.4
通讯作者：
A. Cassano
中科院分区：
文献类型：
--
作者：
Carlos Martín;M. A. Baltanás;A. Cassano
通过光催化过程对水污染物的分解速率可以通过使用完全辐照的光反应器进行定量评估，其中能量吸收率可以精确量化。使用二氧化钛悬浮液作为活性光催化剂，过量的氧气超过化学计量需求，和汞弧灯，我们发现(i)氯仿在水中的光催化分解速率对于[HCCl3]是一级的，对于[O2]是零级的，对于体积能量吸收速率（VREA）大约是半级的。（ii）催化剂浓度的影响在VREA依赖范围内考虑。（iii）这些发现与反应途径相吻合，在中等至高照射条件下，在没有质量输运限制的情况下，光生载流子的重组速率比附着在表面TiIV原子（和/或TiIV原子）上的羟基的空穴捕获速率要快得多。
The rate of decomposition of water pollutants by means of photocatalytic processes can be quantitatively evaluated by using a fully irradiated photoreactor in which the rate of energy absorption is precisely quantified. Using a suspension of titanium dioxide as the active photocatalyst, excess oxygen over the stoichiometric demand, and a mercury arc lamp, we have found that (i) The rate of photocatalytic decomposition of chloroform in water is of first order with respect to [HCCl3], zero order with respect to [O2], and about one-half order with respect to the volumetric rate of energy absorption (VREA). (ii) The effects due to catalyst concentration are accounted for within the VREA dependence. (iii) These findings coincide with a reaction pathway in which, at moderate to high irradiation conditions and in the absence of mass transport limitations, the recombination rate of the photogenerated charge carriers is much faster than the hole trapping by hydroxyl groups attached to surface TiIV atoms (and/or th...