Insights into Cu2O morphology, facet etching, and its hybridized carbonaceous construction for photocatalytic antibiotic pollutant removal

Morphological optimization of Cu2O materials has been the frontrunner in its applications. However, NH4OH optimizations are quite rarely explored regarding Cu2O, which is the main priority of our work. With NH4OH influence, morphology changed from spherical to octahedron-like (octaspheres). Additionally, we could etch the {100} facets at the corners of the Cu2O octa spheres. Morphology variations and {100} facet etchings were studied with FESEM images and material formation with XRD, revealing a peak shift of Cu2O (111). Later, the best Cu2O was hybridized with rGO and g-C3N4 to make a ternary hybrid Cu2O@g-C3N4/rGO (CGR) to degrade antibiotic pollutants tetracycline (TC). It was revealed that Cu+ from dangling bonds of the {111} facets coordinated with TC observed a peak shift in the TC absorbance. A mechanism based on the alignment of Fermi levels of Cu2O, g-C3N4, and rGO was discussed, paving the way for an efficient transfer of photogenerated charge carriers. Robust stability of CGR was determined via post photocatalytic XRD, FESEM, and XPS, wherein no difference between the fresh and used CGR was observed. Analysis of TC intermediates revealed m/z 312 and 358 to be major products in our photocatalytic reaction, and a pathway was also proposed for the same.

Automated summary

Optimization of Cu2O morphology using NH4OH has rarely been explored. In this study, the influence of NH4OH on Cu2O morphology was investigated, and the spherical shape was transformed into octahedron-like octaspheres. The {100} facets at the corners of the Cu2O octaspheres could be etched. The morphology variations and facet etchings were studied using FESEM images and XRD analysis, showing a peak shift in Cu2O (111). Cu2O was then hybridized with rGO and g-C3N4 to form a ternary hybrid CGR, which effectively degraded the antibiotic pollutant tetracycline.