Shining a light on fungicide- water: enhanced photocatalytic degradation using the CoTiO3/CaTiO3 nanocomposite and experimental and theoretical viewpoints on improved intervalence charge transfer from O2− to Ti4+ and from Co2+ to Ti4+ ions and spatial charge transfer

Abstract

Perovskite materials are emerging as the most promising and efficient low-cost energy materials for various applications. The construction of heterojunctions has become a field of interest because of their high potential to give off a large amount of energy. Herein, a Z-scheme heterojunction was made between two perovskites (CoTiO₃ and CaTiO₃) in order to make a cheap material that is good at photocatalysis. Various methods were used to characterize the resulting CoTiO₃/CaTiO₃ (CCO 75 : 25) composite, including XRD, Raman, XPS, HRSEM, HRTEM, BET, and UV-vis. The increased photocatalytic activity of the CoTiO₃/CaTiO₃ (CCO) composite is attributed to the accelerated charge transfer from O²⁻ to Ti⁴⁺ and from Co²⁺ to Ti⁴⁺ ions, revealing the close interfacial contact between CoTiO₃ and CaTiO₃, and spatial charge transfer within the CoTiO₃/CaTiO₃ heterojunction. A direct Z-scheme mechanism was developed, and charge transfer properties were verified by the scavenger test and ESR, PL, and EIS analyses. The enhanced degradation rate of k = 0.0373 min⁻¹ is achieved for the CCO 75 : 25 composite. Meanwhile, the CCO 75 : 25 composite established high photocatalytic stability when recycled for CBZ degradation. This research offers mechanistic and practical views on designing simple and cost-effective materials for pollutant removal.