Cobalt-doped V 2 O 5 hexagonal nanosheets for superior photocatalytic toxic pollutants degradation, Cr (VI) reduction, and photoelectrochemical water oxidation performance

The worldwide energy calamity and ecological disturbances demand materials that can remove harmful contaminants from the polluted water. Recently, semiconductor-based catalytic dye removal has created much consideration due to its high efficacy and eco-friendly contaminated water treatment processes. Vanadium oxide (V 2 O 5 ) has attracted superior attention as a catalyst due to its robust oxidation power, chemical inertness, and stability against photodegradation. In this study, pristine and cobalt (Co)-doped V 2 O 5 samples were synthesized by solvothermal method and examined for their photo-degradation activity and photoelectrochemical (PEC) water oxidation properties. The orthorhombic crystal phase was confirmed by X-ray diffraction (XRD), hexagonal-shaped morphology was observed by scanning electron microscope (SEM) and reduced optical band gap (2.01 eV) was noticed for doped V 2 O 5 catalyst compared to the pristine (2.20 eV) catalyst. The doped V 2 O 5 catalyst exhibited enhanced photodegradation of crystal violet CV (92.7%) and Cr (VI) reduction (90.5%) after 100 min of light irradiation. The doped photocatalyst exhibited approximately 2.1 and 1.9-fold enhancement of photodegradation of CV and Cr(VI) reduction, respectively. The doped electrode showed improved photocurrent density (0.54 mA/cm −2 ) compared to pristine electrode (0.12 mA/cm −2 ). Moreover, the doped electrode showed reduced charge-transfer resistance and enhanced charge-transfer properties compared to those of the pristine electrode. Hence, the prepared hexagonal-shaped V 2 O 5 is a suitable material for the elimination of environmental contaminants from the polluted water as well as water splitting for hydrogen generation.