Accelerated Photocatalyst Degradation of Emerging Environmental Pollutants Via a Novel Z-scheme Functionalized Copper Vanadate/g-C3n4 Heterostructure: Insights into Synergistic Charge Dynamics Mechanism

The increasing prevalence of water contaminants in aquatic environments has raised serious environmental and public health concerns, underscoring the urgent need for efficient water treatment technologies. In this study, a novel Z-scheme heterojunction photocatalyst comprising copper vanadate (Cu2V2O7) and graphitic carbon nitride (g-C3N4) was effectively synthesized via a simple calcination combined with a co-precipitation approach. Comprehensive physicochemical characterizations were conducted to assess the crystallinity, surface morphology, chemical composition, optical features, and charge transfer/separation behavior of the as-synthesized materials. The resulting Cu2V2O7/g-C3N4 (GCV) composite photocatalysts (PCs) confirmed outstanding photocatalytic performance for the degradation of COR dye, achieving 93.8 % removal under visible-light irradiation within 105 min, compared to significantly lower efficiencies of 38.7 % and 62.1 % for pristine CV and GCN catalysts, respectively. Similarly, the degradation of TCH over the GCV composite heterojunction photocatalyst exhibited outstanding performance, achieving 96.6 % removal efficiency, with a rate constant of 0.0308 min-1 , which is 5.5 (0.0056 min-1) and 3.54-fold (0.0087 min-1) advanced than those of pristine CV and GCN, respectively. Radical scavenging trials recognized superoxide radicals (center dot O2-) were the dominant reactive species, followed by hydroxyl radicals (center dot OH), thereby authorizing the primary degradation pathway. A plausible Z-scheme charge transfer mechanism was anticipated based on the band alignment and scavenging outcomes. The greater photocatalytic performance of the GCV composite is attributed to the strong interfacial synergy between Cu2V2O7 and g-C3N4, which promotes efficient charge separation, accelerates electron-hole migration, and prolongs carrier lifetimes via the intrinsic electric field fashioned at the heterojunction interface.