Hard acid soft base (HSAB) guided morphology engineered copper oxides for efficient photocatalytic degradation of textile effluent under visible light

This study demonstrates the synthesis of morphology guided copper oxide nanostructures (CuO) based on Hard Acid and Soft Base concept (HSAB) and their influence on photocatalytic activity under visible light. Herein, we adopted simple chemical bath approach for the synthesis of CuO nanomaterial with different morphologies by using various precursors of copper such as copper nitrate, copper sulfate and copper chloride. The as-synthesized samples were characterized by means of various analytical techniques namely X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV-Visible absorption spectroscopy (UV-VIS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and BrunauerEmmett-Teller surface area analysis (BET). FE-SEM analysis revealed that the as-synthesized CuO, displayed precursor depended morphologies, including horse mane, honeycomb, and aggregated cubic shaped morphologies. Notably, horse mane like copper oxide (henceforth referred to as CuO-1) produced using copper nitrate as a precursor, showed 92.18% towards methylene blue (MB) dye degradation within a span of 180 min under visible light illumination. Thus this study opens the door for the synthesis of other metal oxides with distinct morphologies that could be used for potential photocatalytic applications.