Enhanced photocatalytic degradation of tetracycline hydrochloride by Ag/AgI/WO₃·H₂O composites

Abstract

Novel visible light response Z-scheme Ag/AgI/WO 3 ÁH 2 O composite photocatalysts were synthesized using a two-step hydrothermal method followed by a photoreduction process without adding any surfactant. The synthesized Ag/AgI/WO 3 ÁH 2 O composite (AAW-2) with the Ag/WO 3 ÁH 2 O molar ratio of 0.8/1 showed the highest photodegradation activity for tetracycline hydrochloride (TCH) solution under visible light, and its rate constant was 24.6 times higher than that of WO 3 ÁH 2 O. The enhanced photocatalytic activity of the Ag/AgI/WO 3 ÁH 2 O composite can be due to the efficient separation of the electron-hole pairs through the Z-scheme Ag/AgI/WO 3 ÁH 2 O structure. The AAW-2 composite exhibited excellent stability toward TCH degradation after four successive circulations. Finally, the photocatalytic mechanism of the Ag/AgI/WO 3 ÁH 2 O composite was proposed based on the radical-trapping experiments, where h + and •O 2 À were the main active species during the photocatalytic reaction.

Adsorption and photocatalytic degradation of tetracycline from water by kappa‐carrageenan and iron oxide nanoparticle‐filled poly (acrylonitrile‐co‐N‐vinyl pyrrolidone) composite gel

“…[ 3 ] AOPs are based on the generation of highly reactive but less selective hydroxyl and intermediate radicals by ozonation, electrochemical processes, Fenton or photo Fenton, photolysis, and semiconductor photocatalysis. [ 6 ] Among these various AOPs, semiconductor photocatalysis requiring an oxidizing agent, a photon energy source, and a photosensitive surface is widely reported for the degradation of organic pollutants including antibiotic waste. [ 6–8 ] The rate of photocatalytic degradation is also high.…”

“…[ 6 ] Among these various AOPs, semiconductor photocatalysis requiring an oxidizing agent, a photon energy source, and a photosensitive surface is widely reported for the degradation of organic pollutants including antibiotic waste. [ 6–8 ] The rate of photocatalytic degradation is also high. Bi 2 WO 6 nanosheets showed 90.39% degradation of TC under visible light irradiation.…”

“…[ 9 ] Ag/AgI/WO 3 ·H 2 O composites showed enhanced degradation of TC. [ 6 ] These inorganic photocatalysts have several limitations such as the requirement of expensive centrifugation and drying for recovery of the photocatalysts after use. To overcome these limitations activated carbon, [ 10 ] glass [ 11 ] or polymeric materials [ 12 ] are used as support materials.…”