Ag/Ag3PO4 nanoparticles assembled on sepiolite nanofibers: Enhanced visible-light-driven photocatalysis and the important role of Ag decoration

A novel visible-light-driven Ag/Ag3PO4/sepiolite ternary heterostructure photocatalysts were successfully prepared via a facile precipitation method. The presence of Si-OH on the surface of sepiolite converted the part of Ag + to Ag-0 through the in-situ reduction. the visible light degradation rate constant of Rhodamine B by Ag/Ag3PO4/sepiolite was about 3.68 times higher than that of bare Ag3PO4. The superior photocatalytic perfor-mance of Ag/Ag3PO4/sepiolite was attributed to the formation of Ag3PO4 particles with smaller grain size and Ag-0 nanoparticles due to the introduction of sepiolite, resulting in the enhanced adsorption capacity, improved light response ability and accelerated photogenerated electron transfer rate. In particular, the generated Ag-0 played a very important role in improving the electron-hole separation efficiency through acting as the electron acceptor and regulating the carriers' separation path. On the other hand, the SPR effect of Ag-0 can improve the light absorption ability of the photocatalys. The radical trapping experiment showed that holes (h(+)) and superoxide radical (O-center dot(2)-) were the main reactive species, where the formation of O-center dot(2)- was closely related to the presence of Ag-0. This work provides new insights for the application of hybrid photocatalysts combined with mineral materials in wastewater treatment.

Automated summary

A novel visible-light-driven Ag/Ag3PO4/sepiolite ternary heterostructure photocatalysts were successfully prepared via a facile precipitation method. The presence of Si-OH on the surface of sepiolite converted the part of Ag + to Ag-0 through the in-situ reduction. The superior photocatalytic perfor-mance of Ag/Ag3PO4/sepiolite was attributed to the formation of Ag3PO4 particles with smaller grain size and Ag-0 nanoparticles due to the introduction of sepiolite, resulting in the enhanced adsorption capacity, improved light response ability and accelerated photogenerated electron transfer rate. In particular, the generated Ag-0 played a very important role in improving the electron-hole separation efficiency through acting as the electron acceptor and regulating the carriers' separation path. On the other hand, the SPR effect of Ag-0 can improve the light absorption ability of the photocatalyst. The radical trapping experiment showed that holes (h(+)) and superoxide radical (O-center dot(2)-) were the main reactive species, where the formation of O-center dot(2)- was closely related to the presence of Ag-0. This work provides new insights for the application of hybrid photocatalysts combined with mineral materials in wastewater treatment.