A DFT Study Of Formaldehyde On Functionalized Carbon Nanotubes

Adsorption models of (8,0) single-wall carbon nanotube were founded by Material Studio. The configurations of adsorption models were optimized by density-functional theory. Total energy, binding energy, the closest atoms between target gas molecule and carbon nanotube base, the closest distance and transferring charge of atoms were calculated with formaldehyde on functionalized SWCNT. And the adsorption properties of oxygen, carbon dioxide, water, ammonia, ethanol and toluene adsorbed on amino-group functionalized SWCNT were also calculated to study the selectivity. The results show that the binding energy of HCHO on amino-group functionalized SWCNT is higher than HCHO on pristine SWCNT, with3.71times increase and have better selectivity. The reason of the improvement of binding energy is due to a hydrogen bond between HCHO and amino-group.Otherwise, the adsorption properties of gases adsorbed on carboxyl-group functionalized SWCNT are also studied by density-functional theory. The results show that the binding energy of HCHO on SWCNT is improved by the functionalization of carboxyl-group, though it’s less than that on pristine SWCNT, but the functionalized SWCNT has better selectivity. Two carboxyl-groups functionalized SWCNT was studied. And the binding energy of it reached-2.241eV.The improvements of the functionalization of amino-group are proved by the results derived from density-functional theory. And the results can guide experiments and help to find novel materials.