Controlling the growth of ultrathin MoS2 nanosheets/CdS nanoparticles by two-step solvothermal synthesis for enhancing photocatalytic activities under visible light.

Abstract Heterostructure MoS 2 nanosheets decorated CdS nanoparticles were successfully prepared by a facile two-step solvothermal method. The growth of ultrathin MoS 2 nanosheets on CdS surface in terms of thickness and interlayers of (002) MoS 2 was controlled by changing solvothermal reaction temperature. A series of MoS 2 nanosheets decorated CdS nanoparticles were prepared at different temperature. The synthesized composites were characterized with XRD, FESEM, TEM, UV–vis DRS, BET, PL, XPS, EPR and I-T. TEM observations revealed the growth of ultrathin MoS 2 nanosheets over the CdS nanoparticles, the thickness of MoS 2 sheets and interlayers distance of (002) in composite was found to decrease with increasing the reaction temperature to 220 °C, under the same conditions. Photocatalytic activities of the as-prepared MoS 2 /CdS nanocomposites for the MO degradation were evaluated under the visible light irradiation. The ultrathin MoS 2 /CdS nanocomposites 1–220 with thinner sheets prepared at 220 °C exhibits higher photocatalytic efficiency for degradation of MO under visible light than all the other synthesized samples at different temperature. Furthermore, it was found that this catalyst retains remarkable photocatalytic activity after five cycles. The PL spectrum and photocurrent responses results suggest that the MoS 2 /CdS nanocomposite 1–220 possess higher separation efficiency and minimum recombination of photo-generated electrons and holes than pure CdS. The photocatalytic degradation mechanism of the MO over MoS 2 /CdS nanocomposite was proposed. Graphical abstract Enhanced visible-light photocatalytic degradation MO with high stability could be achieved over the nanocomposite ultrathin nanosheets MoS 2 on CdS nanoparticles with narrow band gap structure. Unlabelled Image Highlights • Ultrathin nanosheets of MoS 2 on CdS nanoparticles were successfully synthesized. • The thicknesses and interlayers distance (002) of MoS 2 on CdS nanoparticles were controlled. • MoS 2 /CdS nanocomposite 1–220, exhibits high photocatalytic activity under visible light. • Photo-generated electrons transferred from CdS to MoS 2 nanosheets [ABSTRACT FROM AUTHOR]