Preparation of Au_(0.5)Pt_(0.5)/MnO_2/cotton catalysts for decomposition of formaldehyde

摘要

Powder Au_(0.5)Pt_(0.5)/MnO_2 and Au _(0.5)Pt_(0.5)/MnO_2/cotton catalysts were successfully prepared by facile methods. The as-prepared catalysts were characterized by means of XRD, SEM, TEM, and TGA. Au_(0.5)Pt _(0.5) alloy NPs were evenly dispersed on the surface of nest-like MnO_2 and no agglomeration was observed. The powder Au _(0.5)Pt_(0.5)/MnO_2 catalyst was adhered to the surface of cotton fibers, and the practical loading amount first increases, and then levels off with increase of the theoretical loading dosage. The Au _(0.5)Pt_(0.5)/MnO_2/cotton catalysts showed excellent catalytic activities for oxidative decomposition of formaldehyde (HCHO). 15 wt% Au_(0.5)Pt_(0.5)/MnO_2/cotton has the highest catalytic activity and the temperature for complete decomposition of HCHO is 120 C. The valence states of MnO_2, MnO_2 porous structures, synergistic effect between Au_(1-x) Pt _x NPs and MnO _2, and synergistic effect between Au_(0.5)Pt _(0.5)/MnO_2 and cotton are considered to be the main reasons for the observed high catalytic activity of Au_(0.5)Pt _(0.5)/MnO_2/cotton catalysts. The Au_(0.5)Pt _(0.5)/MnO_2/cotton catalysts can not only avoid the disadvantages of power catalysts but also improve the catalytic activity; these advantages indicate that Au_(0.5)Pt_(0.5)/MnO_2/cotton catalysts have promising potentials in practical applications.