Mechanism of aniline aerofloat and Cd2+ elimination from mining wastewater by customized S-scheme Halloysite@MoS2/goethite nanotube: Synergy of photo-Fenton decomplexation and adsorption

Aniline aerofloat (AAF) and Cd2+ have caused severe pollution near the mine site, simultaneous remediation technologies are facing enormous challenges due to different reaction conditions of these two pollutants. Herein, a surface optimized Halloysite@MoS2/goethite was established to simultaneously remove AAF-Cd2+ pollution in a photo-Fenton reaction system. The spatial confinement of halloysite nanotube, special surface modulated particle size, acid-base property, and Zeta potential efficiently enhanced photo-Fenton degradation activity and adsorption for cations. 94.2 % of AAF and 94.1 % of Cd-2+ were eliminated within 60 min and the adsorption capacity for Cd2+ reached 68.14 mg g(-1). The built-in electric field between MoS2 and goethite promoted separation of photogenerated carrier via an S-Scheme separation strategy, which maintained high potential electrons in CB and holes in VB for generating reactive oxidation species (ROS). The photocatalysis of MoS2 facilitate to regulate valence of iron species for sustainable activation of H2O2. Combined with HPLC-MS analysis, theoretical calculation of frontier molecular orbital and adsorption energy, the removal mechanism of AAF-Cd2+ was proposed. This study provides novel insights into simultaneous removal of beneficiation reagents-heavy metals combined pollutants and may contribute to remediation of water pollution near the mine sites.

Automated summary

A surface optimized Halloysite@MoS2/goethite material was used to simultaneously remove AAF-Cd2+ pollutants in a photo-Fenton reaction system, achieving high removal efficiency. The built-in electric field between MoS2 and goethite promoted the separation of photogenerated carrier, generating reactive oxidation species. This study provides new insights into the removal of pollutants near mine sites.