Synergistic effects of plasmon induced Ag@Ag3VO4/ZnCr LDH ternary heterostructures towards visible light responsive O2 evolution and phenol oxidation reactions

Abstract

For enhancing solar energy conversion and environmental remediation, noble metal plasmonic photocatalysis originating from the effectual light absorbance and confinement of surface plasmons provides a new promising route. In the present study, by integrating these two aspects, a series of ternary Ag@Ag₃VO₄/ZnCr LDH heterostructures have been prepared by an in situ hydrothermal followed by co-precipitation method. In this method, there is self-assembling of Ag₃VO₄ nanoparticles on the brucite surface of the LDH material along with partial reduction of Ag⁺ to Ag. The phase identity, optical response, and morphological structure of the heterostructure photocatalysts were systematically characterized through PXRD, HRTEM, UV-Vis DRS, PL, and XPS methods. The resulting monodisperse Ag nanoparticles deposited on LDH materials offer a heterogeneous interaction at the interface and exhibit high photocatalytic activity towards generation of O₂ and oxidation of phenol. Evaluation of photocatalytic activity showed that 40 wt% of Ag₃VO₄ modified LDH is the most effective photocatalyst for O₂ evolution (571 μmol) and phenol oxidation (93%). The highly improved photocatalytic performance of the composite was ascribed mainly to the SPR effect of Ag nanoparticles, Schottky barriers formed at the interface of LDH and Ag₃VO₄ nanoparticles, and strong coupling between Ag, Ag₃VO₄ and LDH. The electrochemical studies such as LSV, CV, EIS and Tafel plots further support the high rate of photoactivity towards O₂ evolution and phenol oxidation. These newly designed plasmonic Ag–LDH nanoheterostructures may offer a promising strategy for maximum light absorption and be authoritative in meeting environmental claims in the future.