A simplistic approach for the synthesis of CuS-CdS heterostructure: A novel photo catalyst for oxidative dye degradation

[Display omitted] •Surfactant free CuS-CdS heterostructures were successfully synthesized using the HMDS-assisted synthesis method.•We have demonstrated CuS-CdS heterostructures having clean surfaces as photo catalyst for the degradation of rhodamine B (RhB) (96.0% in 10 min) and methylene blue (MB) (94.7% in 9 min) under visible light (λ > 420 nm) irradiation.•The higher photocatalytic activity was explained by the availability of clean surfaces and CuS-CdS heterostructures.•The clean surfaces and heterostructure formation of nanoparticles supported a fast separation of photo excited electrons under visible light illumination.•The present work endorsed the importance of semiconductor heterostrcutures with clean surfaces to achieve tremendous catalytic activity for environmental remediation. Direct synthesis of CuS-CdS based mesoporous composite materials and their photocatalytic activity are delineated. In this study, a series of CuS micro flowers (mf) decorated with varying amounts of CdS nanoparticles (NP) have been synthesized successfully in a controlled manner. Relatively easy synthesis of material along with its surfactant-free clean surfaced heterojunction accentuates the reliability of the protocol described here. Full characterization of these semiconducting materials was accomplished with a series of analytical techniques, which include powder x-ray diffraction (PXRD), scanning electron microscopy (SEM), tunnelling electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), UV–vis, IR, BET and lifetime studies. Upon varying the concentration of precursor of Cd in the reactions, the resulting materials exhibited a well-demarcated change in morphologies ranging from undifferentiated mass to well-differentiated flower-like architectures. The thoroughly characterized composite was accessed finally for its potential photocatalytic activity for the degradation of organic dyes. The results showed 96.0% degradation of rhodamine B (RhB) over 10 min and 94.7% degradation of methylene blue (MB) over 9 min. This observed rate of degradation was much higher compared to that observed in the case of pure CuS (62.0% of RhB and 50.2% of MB).