Layered Sulfur Nanosheets Prepared by Assembly of Sulfur Quantum Dots: Implications for Wide Optical Absorption and Multiwavelength Photoluminescence
Zhuangwei Bai, Lihua Shen, Jianhang Wei, Yuangang Li, Azhar Abbas, Yinyan Li, Mengnan Qu, Dongdong Zhang, Chengxiao Zhang
Abstract
Preparation, characterization, and optical properties of layered sulfur nanosheets (S-NSs) from natural sublimed sulfur were reported in this work. Few-layered S-NSs were prepared by a developed liquid-phase method including three steps: (1) forming sulfur quantum dots from natural sublimed sulfur; (2) forming multilayered nanosheets by assembling sulfur quantum dots through the hydrothermal method; and (3) sonication exfoliation of the multilayered S-NSs. The thinnest S-NSs (sulfurene) with a 0.84 nm thickness were obtained by the developed method. The obtained S-NSs showed wide-range absorption from ultraviolet to the visible region, multiwavelength photoluminescence, and superb water dispersibility and stability over two months in air. A reduction current peak was observed at −1.2 V (vs Ag/AgCl, Sat. KCl) on a fluorine-doped tin oxide electrode in 0.010 M HCl containing S-NSs, which is attributed to the reduction from S0 to S2– of the S-NSs. These alternative two-dimensional (2D) nanosheets of S-NSs with good stability and water dispersibility will provide opportunities for the research fields of visible-light-active photocatalysis and optical sensing.