Directed producing singlet oxygen for tetracycline hydrochloride degradation using red mud-based heterojunction within sonophotocatalysis system

Sonophotocatalysis (SPC) has been designed as an emerging treatment technology to degrade organic pollutants in wastewater. Reed and Red mud waste were utilized to synthesize a novel heterojunction catalyst (RSRM50-1100) through co-pyrolysis processes. Several characterization tests and density functional theory (DFT) calculations confirmed that the FeAl 2 O 4 /Fe 3 O 4 /BC heterojunction was present in RSRM50-1100, and the spontaneous electron transfer occurred from FeAl 2 O 4 to Fe 3 O 4 within the heterojunction. Meanwhile, RSRM50-1100 exhibited excellent degradation and photoelectric properties in SPC system. Furthermore, a series of free radical identification experiments confirmed that 1 O 2 was dominant in the SPC system of RSRM50-1100. The generation of 1 O 2 stemmed from the reaction of h + / · O 2 − and •OH/ · O 2 − , with the •OH/ · O 2 − reaction dominating. These findings not only showed that a novel photocatalyst RSRM50-1100 had an excellent performance for mitigating water pollution, but also proposed a promising strategy for disposing solid wastes.