The results of this reaction are hydroxyl radicals, which attack both inorganic and organic compounds, and turn them into molecules that can be harmlessly washed away with the next rainfall.

• 它能清净空气，因为它是个有效的光催化剂：加速阳光中的紫外线分解空气中水分子的速度，这个反应产生的羟基自由基，会攻击空气中的有机或无机化合物，将它们变成无害的分子，而且下一场雨就可以冲走了。