Rational design of S-scheme AgI/ZrTiO heterojunctions for remarkably boosted norfloxacin degradation.

Emerging S-scheme heterojunction photocatalysts endowed with efficient charge separation and strong redox capacity have stimulated wide interests in dealing with environmental issues nowadays. In this work, we firstly fabricated the oxygen vacancy modified ZrTiO nanocrystals, which was further combined with AgI to build the defective S-scheme AgI/ZrTiO heterojunctions for visible-light photocatalytic norfloxacin degradation. The synthesized ZrTiO nanocrystals and AgI/ZrTiO heterojunctions displayed remarkably boosted norfloxacin degradation performance under visible-light irradiation. The reaction rate constant of the optimized AgI/ZrTiO-5% heterojunction is as high as 0.01419 min, which is approximately 43.35 times that of AgI and 7.93 times that of ZrTiO nanocrystals, and far superior to those of commercial TiO and commercial ZrO. The high-performance photocatalytic norfloxacin degradation could be mainly attributed to the formation of S-scheme charge transfer pathways and oxygen vacancy defects. More significantly, AgI/ZrTiO could also realize the effective photo-decomposition of other emerging pollutants. Finally, the visible-light photocatalytic performance and photocatalysis mechanism were investigated.