Sheet-like and truncated-dodecahedron-like AgI structures via a surfactant-assisted protocol and their morphology-dependent photocatalytic performance

Abstract

Silver halide-based structures have been attracting great interest as efficient visible-light-driven photocatalysts towards the photodegradation of organic pollutants, and those studies focusing on their morphology-dependent catalytic performances have received particular attention. While great advancements in this regard have been witnessed in the past few years with respect to AgCl- and AgBr-based photocatalysts, relevant explorations concerning AgI-based species are relatively rare, even though the excellent durability of AgI-based structures renders them attractive candidates for potential photocatalytic uses. By means of chemical reactions between AgNO₃ and tetramethylammonium iodide (TMAI), and AgNO₃ and tetrabutylammonium iodide (TBAI), we herein report that AgI structures with a sheet-like and a truncated-dodecahedron-like morphology, respectively, could be controllably synthesized via a surfactant-assisted fabrication protocol. In our synthesis systems, AgNO₃ works as the silver source, while the TMAI and TBAI surfactants serve not only as an iodine source but also as a directing reagent for controllable fabrication. It has been demonstrated that our AgI structures could work as visible-light-energized photocatalysts towards the photodegradation of methyl orange. We find that compared to their sheet-like counterparts, the truncated-dodecahedron-like AgI architectures exhibit substantially boosted catalytic performances. Moreover, we disclose that our truncated-dodecahedron-like AgI-based species could display excellent photocatalytic stability, wherein their catalytic reactivity displays only trivial fluctuations under visible-light irradiation even after the photoreactions have been repeated 22 times continuously. Our work might not only introduce a facile protocol for the controllable synthesis of AgI structures but also pave an avenue for facile enhancement of their catalytic performances via morphology alterations.