Z‐Scheme TiO₂/g‐C₃N₄ Activation of Peroxymonosulfate to Remove Organic Pollutants: Properties and Mechanism

Abstract

TiO2/g‐C3N4 hybrids (TCNs) were constructed by an ammonium salt‐assisted hydrothermal‐high temperature calcination method and used to activate peroxymonosulfate (PMS) to degrade multiple simulated pollutants. The Z‐scheme heterojunction between TiO2 and g‐C3N4 can effectively promote the separation of electron‐hole pairs and improve the photocatalytic activation effect of TCN. The degradation efficiency of RhB in the TCN1/PMS system was 92.3 %, which was only 59.8 % and 63.2 % in g‐C3N4 /PMS the g‐C3 N4/PMS system and TiO2/PMS system, respectively, after 60 min of reaction under sunlight. The TCN1‐4 sample prepared by adding (NH4)2SO4 into the precursor of TCN1 has a higher specific surface area (116.44 m2/g), which provides a better photocatalytic activation effect on PMS: the degradation efficiency of RhB in the TCN1‐4/PMS system can reach 93.9 % after 30 min, which was similar to that of the TCN1/PMS system after 60 min (92.3 %), and the reaction efficiency was doubled. Radical quenching experiments showed that free radicals (⋅OH, SO4⋅−, ⋅O2−), nonradicals (1O2) and h+ existed in the TCN1‐4/PMS reaction system.