Fig. 5: Determination of Cr(VI) removal efficiency using C/Co (ppm) vs. time (min) plots.

a Photocatalytic reduction of Cr(VI) solutions with initial concentrations of 20–1000 ppm for 420 min. b Ratio of removed and remaining Cr(VI) concentrations after reduction. c Pseudo-first-order linear-fitted plots of Cr(VI) solutions of various concentrations. d Rate constants and half-life of the reaction. The error bars represent the SD (n = 3).