Degradation of azo dye Orange II under dark ambient conditions by calcium strontium copper perovskite
Degradation of azo dye Orange II under dark ambient conditions by calcium strontium copper perovskite
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DOI：
10.1016/j.apcatb.2017.09.056
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发表时间：
2018-02-01
影响因子：
22.1
通讯作者：
da Costa, Joao C. Diniz
中科院分区：
文献类型：
--
作者：
Chen, Huihuang;Motuzas, Julius;da Costa, Joao C. Diniz
本工作考察了钙锶铜(CSC)基催化剂在黑暗条件下对偶氮染料橙II(OII)的降解效果，在没有添加过氧化氢或臭氧的情况下。采用EDTA-柠檬酸络合法制备了CSC。合成的催化剂由钙钛矿相和金属氧化物组成，但钙钛矿相对OII的降解活性最高。钙钛矿结构中A位的钙、锶含量不同，而B位为富铜位。A位钙含量较高的CSC化合物对OII的降解效果略好。在黑暗条件下降解动力学较快，10min内可降解高达80%的OII。TOC结果表明，有机碳的降解只是部分的，因为60%以上的有机碳留在溶液中，并由高效液相色谱测定的副产物的形成来支持。剩余的碳被发现吸附在废CSC催化剂的表面上，作为反应的副产物和OII分子。结果表明，CSC催化剂能有效地从低浓度(10ppm)到高浓度(100ppm)的溶液中断裂-N=N-键。这个反应产生电子，产生自由基物种，包括异丙醇证实的羟基自由基，进一步降解OII及其副产物。
This work investigates the effect of calcium strontium copper (CSC) based catalysts for the degradation of an azo dye orange II (OII) under dark conditions without the addition of peroxides or ozone. CSC were synthesized via a combined EDTA-citric acid complexation method. The resultant catalyst was composed of perovskite and metal oxide phases, however, the perovskite phase was the most active for degradation of OII. The content of Ca and Sr in the A-site of the perovskite structure was varied whilst the B-site was Cu rich. CSC compounds with higher Ca content in the A-site were slightly more effective at degrading OII. The degradation kinetics under dark conditions was fast with up to 80% of OII being degraded within 10 min. TOC results showed that the degradation was only partial as more than 60% of the organic carbon remained in the solution, supported by the formation of by-products determined by HPLC. The remainder of the carbon were found to be adsorbed on the surface of the spent CSC catalyst, as by-products of the reaction and OII molecules. The CSC catalyst proved to be effective for breaking -N=N- bonds from solutions containing low (10 ppm) to high (100 ppm) OII concentrations. This reaction produced electrons which generated radical species, including hydroxyl radicals as confirmed by 2-propanol, which further degraded OII and its by-products.