L-cysteine and urea synergistically-mediated one-pot one-step self-transformed hydrothermal synthesis of p-Ag2S/n-AgInS2 core-shell heteronanoflowers for photocatalytic MO degradation

A novel core-shell heterojunction of p-Ag 2 S/n-AgInS 2 nanoflowers built by interlaced and slightly-curved nanosheets is fabricated for the first time by a facile one-pot one-step L-cysteine and urea synergistically-mediated hydrothermal method and demonstrates 36- and 3.4-fold enhancement for MO degradation under visible light as compared to neat Ag 2 S and AgInS 2 , respectively. • p-Ag 2 S/n-AgInS 2 core-shell heteronanoflowers fabricated by a facile one-pot hydrothermal route. • A sacrificial in-situ self-transformation mechanism was proposed. • Better photocatalytic performance for MO degradation than neat Ag 2 S and AgInS 2 . Delicate design and construction of Ag 2 S-based heterostructures with favorable interface for prominent charge separation is a grand challenge in photocatalysis. In this work, the large-scale fabrication of core-shell p-Ag 2 S/n-AgInS 2 hetero-nanoflowers with interlaced nanosheets is demonstrated firstly by a facile one-pot one-step L-cysteine and urea co-mediated hydrothermal method. Here in-situ partial self-transformation of initially-generated monoclinic Ag 2 S nuclei (core) to orthorhombic AgInS 2 (shell) plays a critical role in creating an atomic-level p-n nanojunction between p-Ag 2 S and n-AgInS 2, which is validated by various techniques including XRD, SEM, HR(TEM), EDS, XPS, N 2 adsorption/desorption and UV–vis DRS spectra. Benefiting from the enhanced light-response and charge-separation due to the establishment of p-n heterojunction, the photocatalytic activity of Ag 2 S/AgInS 2 heteronanoflowers (In/Ag = 1.0, molar ratio) for MO degradation under visible light is nearly 36 and 3.4 times higher than that of pristine Ag 2 S and AgInS 2 , respectively. More Intriguingly, Ag 2 S/AgInS 2 hetero-nanoflowers manifest exceptionally preferable photo- and chemical-stability as well as anti-photocorrosion capability, a formidable challenge encountered in many chalcogenides. This work not only highlights the great potential of Ag 2 S/AgInS 2 hetero-nanoflowers as a less-toxic visible-light active photocatalyst, but also affords a cost-competitive and eco-friendly one-pot strategy towards in-situ fabrication of sulfide-based heterostructures with favorable interface for good performance in solar energy-related applications.