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-TiO2(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 TiO2 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-TiO2 (am) is obtained and compared with that of amorphous titanium dioxide [TiO2(am)] and the crystalline phase of hybrid (C-TiO2). The dye removal percentages of TiO2 (am) and C-TiO2 are ca.3% and ca.32%, respectively, which is feeble compared to the dye removal percentage of C-TiO2 (am) (ca. 98%). The possible mechanism of organic dye adsorption of C-TiO2 (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-TiO2 (am) suggest that it can be considered as a new potential adsorbent for water purification. The remarkable characteristic adsorption features of C-TiO2 (am) suggest that it can be considered as a new potential adsorbent for water purification.