Microporous carbon with highly dispersed nano-lanthanum oxide (La2O3) for enhanced adsorption of methylene blue

Activated carbon doped with Lanthanum compounds are prepared and used as a preferred material for adsorption treatment systems. In this study, use of nano La2O3 and La3+ is attempted as tuning agents for granular activated carbons (GAC) and products are marked as GACLaX and GACLaOX series, produced under controlled activation (473-1273 K) for a Lanthanum/carbon ratio 0.04. They were tested for their physico-chemical features, textural superiority, and efficiency determined by XRD, FTIR, SEM, XPS, Raman, and N2/ BET and t-plots. It is found that carbon GACLaO873 (GAC activated with nano lanthanum oxide at 873 K) has good microporosity and adsorption efficiency. Nano La2O3 and La3+ incorporated extra microporosity (SAmicro) measured as 707 m(2)/g for GACLaO873 compared to native carbon GAC (589 m(2)/g). The respective surface area (SABET) of these new carbons are determined as 946 m(2)/g (GACLaO873), 953 m(2)/g (GACLa1073), and 997 m(2)/g (GAC383). Suitability of the new carbon materials in solid-liquid batch reactor systems is studied for methylene blue (MB) in concentration ranges 25-1500 mg/L. Analysis of equilibrium isotherm uptake data by John-Sivanandan Achari isotherm model found distinct features of different adsorption phases (kinks) in their plots. For GACLaO873, monolayer coverage qm(J-SA) has been 256 mg/g against the basic carbon GAC383 (190 mg/ g). Lanthanum activated carbon GACLa1073 has been noted with adsorption efficiency for metal ions, Mn (99.3%), Fe (99.1%), Co (96.6%), As (76.3%), Ba (63.0%), Li (50.4%), Al (71.3%), Cr (47.7%), Ni (99.2%), Cu (7.11%), Zn (24.3%), Cd (55.1%), Tl (32.6%) and Pd (94.9%) tested for a contaminated groundwater sample as a field trial. Lanthanum, La3+, and nano La2O3 doped activated carbon series (GACLaX and GACLaOX) prepared under a controlled condition and activation temperature X, bears good microporosity and adsorption efficiency for organic and metal ion contaminants.

Automated summary

Activated carbon doped with Lanthanum compounds exhibits enhanced microporosity and adsorption efficiency, especially in the case of GACLaO873 activated with nano lanthanum oxide at 873K. The Lanthanum-activated carbon GACLa1073 shows high adsorption efficiency for metal ions, making it suitable for organic and metal ion contamination treatment.