Caterpillar-like Ag–ZnO–C hollow nanocomposites for efficient solar photocatalytic degradation and disinfection

Abstract

Engineering a highly accessible semiconductor with optimized physicochemical structure for efficient photocatalysis under visible light is never-ending. Herein, a facile route was developed to fabricate a caterpillar-like ZnO–C (ZC) hollow nanocomposite by directly pyrolyzing Zn-BTC MOF microrods and nanorods, which have been previously synthesized via a rapid supersonic-assisted aqueous reaction at room temperature. It is demonstrated that the ZC nanorods radically grow on the surface of the hollow nanocomposite directly converted from MOF-microrods at 550 °C and form a caterpillar-like catalyst based on an oriented attachment mechanism. After in situ photo-reduction of AgNO₃, the Ag–ZnO–C (AZC550) nanocomposite catalyst possesses ultrahigh photodegradation turnover frequency (TOF) values towards methyl blue (3.00 × 10⁻³ mol mol⁻¹ min⁻¹), 4-nitrophenol (0.14 × 10⁻³ mol mol⁻¹ min⁻¹) and amoxicillin (3.43 × 10⁻³ mol mol⁻¹ min⁻¹), as well as a photo-inactivation activity of 6.25 × 10⁵ cfu mg⁻¹ min⁻¹ towards E. coli, outperforming most state-of-the-art catalysts reported thus far. The ameliorated photocatalytic performance and recyclability can be assigned to the synergistic effects between the Zn–C hierarchical nanoarchitecture and Ag-NPs. This work provides a new approach for the design of efficient solar photocatalysts.