Defect Induced Ultrafast Organic Dye Adsorption by Amorphous Titanium Dioxide/Phosphorus-Doped Carbon Nanodot Hybrid

The research article introduces the unexplored synergistic effect of amorphous titanium dioxide and phosphorus-doped carbon nanodot hybrid [C-TiO 2 (am)] for the ultrafast adsorption of methylene blue and crystal violet dyes. The hybrid eliminates 98% of methylene blue dye (MB) at a concentration of 32 mg/L and 96% of crystal violet dye at a concentration of 62 mg/L from the aqueous solution within 5 min of contact time at ambient temperature. The incorporation of phosphorus-doped carbon nanodot in amorphous TiO 2 modifies the oxygen vacancy, which enhances the material's affinity for organic dyes like MB and crystal violet. The significance of defects on the adsorption efficiency of C-TiO 2 (am) is obtained and compared with that of amorphous titanium dioxide [TiO 2 (am)] and the crystalline phase of hybrid (C-TiO 2 ). The dye removal percentages of TiO 2 (am) and C-TiO 2 are ca.3% and ca.32%, respectively, which is feeble compared to the dye removal percentage of C-TiO 2 (am) (ca. 98%). The possible mechanism of organic dye adsorption of C-TiO 2 (am) is derived through the detailed discussion of porosity, morphology, functional groups, and chemical compositions. The impact of temperature on dye adsorption and removal rate is determined using non-linear regression analysis. The remarkable characteristic adsorption features of C-TiO 2 (am) suggest that it can be considered as a new potential adsorbent for water purification. The remarkable characteristic adsorption features of C-TiO 2 (am) suggest that it can be considered as a new potential adsorbent for water purification.