Facilely prepared Bi4O7 modified commercial Ga2O3 with optimized photocatalytic efficiency for perfluorooctanoic acid degradation

As a persistent contaminant with significant risks to environment, health and ecology, perfluorooctanoic acid (PFOA) is urgent to be treated from water. To improve the performance of commercial Ga 2 O 3 in the photocatalytic degradation of PFOA, a Bi 4 O 7 -Ga 2 O 3 composite was facilely obtained through a hydrothermal route, and characterized with diverse techniques. Batch tests were conducted to evaluate the impacts from the experimental conditions on PFOA degradation, where the Bi 4 O 7 -Ga 2 O 3 composite (GaBi10) exhibited optimized photocatalytic performance stems from the enhanced light response, improved separation of photo-generated carriers, and increased adsorption capacity, attributed by Bi 4 O 7 incorporation. Furthermore, a universal parameter, catalytic efficiency ( η ) is proposed for the quantitative comparison of photocatalytic performance across different studies, which demonstrate the outstanding performance of GaBi10 in PFOA degradation, defluorination and mineralization. The quenching tests and intermediates analysis were executed to explore the mechanism underlying the photocatalytic degradation, which indicated the degradation is initiated by h + , and other active species, ·O 2 – and ·OH, propel the mineralization of the intermediates derived from PFOA. The findings provide valuable insights for developing commercial photocatalyst and understanding photocatalytic degradation of PFOA.