First principles calculations on the structures, electronic and magnetic properties of the TMn@W12O36 (TM=Mn, Fe, Co and Ni, n = 1–4) clusters

Abstract

Transition metal (Mn, Fe, Co and Ni)-doped tungsten oxides nanoparticles with magnetic properties may be applied in various catalysts such as water treatment as they are easy to be recycled. Structural, electronic and magnetic properties of TMn@W[Formula: see text]O[Formula: see text] (TM=Mn, Fe, Co and Ni, n=1–4) clusters have been calculated at PBE level. The results reveal that the centers of the TM[Formula: see text] clusters are in accordance with that of the W[Formula: see text]O[Formula: see text] clusters while the TM4 clusters deviate obviously from the center of the W[Formula: see text]O[Formula: see text] cages. All TMn@W[Formula: see text]O[Formula: see text] clusters exhibit slightly less structural stability and obviously more chemical reactivity than the W[Formula: see text]O[Formula: see text] clusters. Mülliken spin densities of a TM atom embedded are almost kept except for the Ni@W[Formula: see text]O[Formula: see text] clusters. The spin densities of TMn clusters in the TM3@W[Formula: see text]O[Formula: see text] and TM4@W[Formula: see text]O[Formula: see text] clusters are offset. The magnetic TM modification strategy is helpful to design recyclable tungsten oxide catalysts.