NIR-response amorphous FeOOH anchored BiO2-x for chlorophenols photodegradation via molecular oxygen activation

Chlorophenols (CPs) are universal and toxic pollutants in nature, as they have been widely detected in surface water, groundwater, sediment, ambient air, soil, and the human body. In this work, novel FeOOH/BiO2-x binary heterostructure composites with UV-Vis-NIR full-spectrum response were successfully constructed by anchoring highly dispersed amorphous FeOOH on BiO2-x nanosheets. A series characterization indicated the binary components were successfully obtained. The FeOOH/BiO2-x photocatalysts exhibited highly enhanced photocatalytic activity for the degradation of chlorophenols under UV-Vis-NIR full-spectrum irradiation. The amorphous FeOOH could effectively broaden the light response range, modulate the energy band structure and promote the separation and transfer of photogenerated electron-holes pairs, thus boosting the activation of molecular oxygen to generate •O2–. Furthermore, FeOOH/BiO2-x maintained excellent photocatalytic performance upon real solar light of varied irradiance for consecutive 7 days, indicative of great potential towards phenolic pollutants degradation in water. The redox couples of Fe3+/Fe2+ and Bi(3+x)+/Bi3+ also accelerate the efficient generation of reactive oxygen species over FeOOH/BiO2-x with improved durability. This work not only contributes to the design of full-spectrum responsive photocatalysts, but also provides a rational strategy for molecular oxygen activation towards the elimination of emerging contaminants.