Water pollution by dyes is a major health and environmental issue. Photosensitive organic dyes produce hydrated electrons, e_aq⁻, singlet oxygen, ¹O₂, and superoxide anion radicals, O₂·⁻. O₂·⁻ catalyzes H₂O₂ transformation into hydroxyl radicals ·OH, which can be used to degrade wastewater under sunlight. Here, we measured e_aq⁻, ¹O₂, O₂·⁻ and ·OH generated under visible light irradiation of photosensitive organic dyes in the presence of the auxiliary Fe³⁺, the 1,5-diphenylcarbazide molecular probe, the NH₂OH molecular probe and the dimethyl sulphoxide probe. Results show that single photosensitive organic dyes are not degraded in the visible light/H₂O₂ system. However, they were degraded when mixed in a certain proportion to produce a brown coloration, a phenomenon named the ‘color-mixing effect.’ Likewise, the average yields of O₂·⁻ in single photosensitive organic dye solutions were lower, of 0.015 (ΔA₅₁₀), than that in mixed brown solutions, of 0.113. The color-mixing effect is explained mainly by higher ·OH generation from increased O₂·⁻ production. Findings imply that sunlight irradiation is a promising way to clean colorful and dye-containing wastewater.

染料对水的污染是主要的健康和环境问题。感光性有机染料产生水合电子，ë_水溶液^- ，单线态氧，¹ Ò ₂，和超氧化物阴离子自由基，O- ₂ · ^- 。O ₂ · ^-催化H ₂ O ₂转化为羟基自由基·OH，可用于降解阳光下的废水。在这里，我们测量ë_水溶液^- ，¹ Ò ₂，O- ₂ · ^-·OH在辅助Fe ³⁺，1，5-二苯基咔嗪分子探针，NH ₂ OH分子探针和二甲基亚砜探针的存在下在光敏有机染料的可见光照射下生成。结果表明，单一的光敏有机染料在可见光/ H ₂ O ₂系统中不会降解。但是，它们按一定比例混合后会降解，产生棕色，这种现象称为“颜色混合效应”。同样地，O-的平均产量₂ · ^-在单个感光有机染料溶液均降低，0.015（Δ阿₅₁₀），而不是混合棕色溶液中的0.113。主要通过增加O ₂ · ^-产生的更高的·OH生成来解释颜色混合效果。研究结果表明，阳光照射是一种清洁有色和含染料废水的有前途的方法。