Constructing aloe-emodin/FeOOH organic-inorganic heterojunction for synergetic photocatalysis-Fenton eliminating antibiotic pollutants

Photocatalysis-Fenton degradation of antibiotic pollutants is an attractive avenue, but its practical application is limited by easy recombination of photocarriers and low efficiency of Fe 3+ /Fe 2+ cycling. This work intends to introduce aloe-emodin into FeOOH with the purpose of improving the carrier separation rate by organic-inorganic heterojunction , as well as promoting the iron cycle (Fe 3+ /Fe 2+ ) transformation and inhibiting Fe 3+ precipitation in photocatalysis-Fenton through its complexation and reducibility, so as to achieve efficient degradation of antibiotic pollutants. Conspicuously, the prepared aloe-emodin/FeOOH sample showed nearly 85% tetracycline (TC) removed within 1 h with visible light and H 2 O 2 , which was almost 2.02 and 2.12 times larger than those of aloe-emodin and FeOOH, separately. The superior degradation performance ascribed to the synergistic effect of the aloe-emodin and FeOOH in the presence of H 2 O 2 as a strong oxidant. Moreover, the paper is focused on the effects of aloe-emodin/FeOOH interface structural characteristics on transmission modes of carriers and surface catalytic kinetics. The generated •OH, •O 2 − and 1 O 2 could serve as the active species achieving relatively high efficiency of Fe 3+ /Fe 2+ cycling and rapidly photogenerated charge separation in the degradation progress. Finally, we have tried to illustrate the internal mechanism of photocatalysis-Fenton treatment of antibiotic pollutants by aloe-emodin/FeOOH. Additionally, these investigations will provide practical and technical support for further exploitation of similar organic-inorganic photocatalysts, which is expected to accelerate the development of photocatalysis-Fenton degradation in the field of environmental purification.