https://doi.org/10.1007/s10854-025-14259-3
Abstract
Measures to save our water bodies from pollutants are crucial for the healthysustenance of life in this age of water scarcity. Photocatalysis is an effective toolfor the treatment of water polluted by various industrial effluents. Here, potassium(K) doping is done to engineer the structural, morphological and opticalproperties of TiO2nanotube arrays for the improvement of its photocatalyticdegradation efficiency. Doping enhanced the photocatalytic degradation ratesto ~ 96% in 120 min and ~ 97% in 180 min, respectively, for crystal violet andmethylene blue dyes from the respective values of 70% and 55% for pristine TiO2nanotubes. The fabrication and doping of the nanotube arrays vertically alignedover titanium foil are done by the cost-effective electrochemical method. Frommultiple characterizations, the enhancement in the photocatalytic efficiency of thedoped nanotube arrays is ascribed mainly to the drastic reduction in the band gapfrom UV to the visible range, formation of carrier trap centers by reduction of Ti4+to Ti3+/Ti2+ states, presence of more hydroxyl groups, an increased orientation ofK+doped nano-crystallites along (004) plane.