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利用自旋俘获－电子自旋共振（ＳＴ－ＥＳＲ）方法，使用光催化剂（纳米氧化锌粉末）在纯水、甲醛、甲酸水溶液中进行紫外光化学反应。使用自旋捕获剂ＤＭＰＯ俘获反应过程中的自由基中间体，检测到羟基加合物（ＤＭＰＯ－ＯＨ）、甲醛基加合物（ＤＭＰＯ－ＣＨＯ）、以及碳中心自由基加合物（ＤＭＰＯ－ＣＯ－２）的ＥＳＲ信号。这些加合物均产生于溶液的光氧化过程。实验表明，在ＺｎＯ存在的体系中，甲醛易被羟基氧化。水在光氧化的过程中起了关键性的作用。
The photocatalyst (nano zinc oxide powder) was used to conduct the UV chemical reaction in pure water, formaldehyde, aqueous solution of formic acid by spin-trapping-electron spin resonance (ST-ESR) The hydroxyl intermediate (DMPO-OH), formaldehyde-based adduct (DMPO-CHO) and the carbon center radical adduct (DMPO- CO-2) ESR signal. These adducts are all generated by the photooxidation of the solution. Experiments show that in the presence of ZnO system, formaldehyde is easily hydroxylated. Water plays a key role in the photooxidation process.