HPLC‐MS and UV‐visible coupled analysis of methylene blue photodegradation by hydrothermally‐grown ZnO nanowires

Photocatalysis is an efficient and promising method to purify water. Numerous studies have been dedicated demonstrate its efficiency on several hazardous compounds, derived from various industries. However, even if the degradation of such products has extensively studied, obtaining information their photodegradation pathway still challenging, leading concerns about innocuousness treated In this study, authors use ZnO nanowires (ZnO NWs), photodegrade a solution commonly used organic dye methylene blue (MB) under ultraviolet (UV) irradiation, followed simultaneously by UV‐visible (UV‐vis) spectrometry high‐performance liquid chromatography coupled with mass (HPLC‐MS). Combining these two methods real‐time mechanism are given. The HPLC‐MS analysis allows us confidently identify three reaction intermediates MB degradation: Azure A, B C, as well spot other uncertain formulas, presented hypothesis beginning pathway. While shows total after 2 h photodegradation, indicates that some remain in solution. Its quantity calculated be 14 μg L −1 , which harmless humans.