The surface plasmon resonance effect on the enhancement of photodegradation activity by Au/ZnSn(OH)6 nanocubes

Abstract

We demonstrated Au/ZnSn(OH)₆ hollow nanocubes that exhibited extremely high photodegradation activity under ultraviolet and visible-light illumination. The pristine ZnSn(OH)₆ hollow nanocubes can achieve a 100% photodegradation ratio within 20 min under ultraviolet-light illumination. The high photodegradation activity of ZnSn(OH)₆ can be attributed to plenty of OH groups present in the polyhedral corner of the ZnSn(OH)₆ that generate a large number of reactive hydroxyl radicals for degradation of dye molecules. High resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) images revealed that the size of the ZnSn(OH)₆ and Au/ZnSn(OH)₆ hollow nanocubes is ∼30–80 nm. After ZnSn(OH)₆ nanocubes were decorated with Au, the heterostructures exhibited a significantly strong and widened absorption peak in the range 450–750 nm because of the surface plasmon resonance (SPR) effect, and therefore showed an excellent photodegradation activity under visible-light illumination. The rate constant k of Au/ZnSn(OH)₆ is as high as 51.8 L mol⁻¹ min⁻¹ under UV-light illumination. This value is much higher than those reported so far. The hydroxyl groups essentially enhance the reaction rate and enable the active radicals to participate in the reaction for destruction of the Rhodamine B (RB) solution. Au/ZnSn(OH)₆ has been successfully applied for preparing hybrid coating screens with polydimethylsiloxane (PDMS), which exhibited an excellent mechanical desirable durability and extended its feasible application in our daily lives.