Deep insight into ROS mediated direct and hydroxylated dichlorination process for efficient photocatalytic sodium pentachlorophenate mineralization

Herein, we designed and constructed a model photocatalyst oxygen-deficient Bi@Bi2MoO6 (Bi-BMO-OVs) through a one-step solvothermal synthesis to deliberately regulate ROS generation and seek the crucial function of ROS during sodium pentachlorophenate (NaPCP) photochemical decomposition. The metallic Bi and oxygen vacancies (OVs) introduced in Bi2MoO6 prominently encouraged the yields of O-1(2) and O-center dot(2)-, and synchronously blocked the formation of powerful (OH)-O-center dot. Unlike the nonselective performance of (OH)-O-center dot, O-1(2) and O-center dot(2)- were experimentally and theoretically substantiated to account for the direct dichlorination and hydroxylated dichlorination respectively during photocatalytic NaPCP decomposition. With more O-center dot(2)- and O-1(2) involved in the dechlorination process of NaPCP, easily decomposable quinone intermediates were produced, thereby realizing the rapid and efficient mineralization of NaPCP. This present work casts a new light on ROS mediated visible light photocatalytic decomposition of polychlorinated organic pollutants and opens up new possibilities for achieving their rapid detoxication via precise ROS regulation.

Automated summary

By designing a model photocatalyst with oxygen deficiency Bi@Bi2MoO6, this study effectively increased the yields of O-1(2) and O•(2)- while blocking the formation of (OH)•, leading to rapid and efficient mineralization of NaPCP during photocatalytic decomposition. This work sheds new light on the visible light photocatalytic decomposition of polychlorinated organic pollutants via precise regulation of ROS.