Heteroarchitectured Ag–Bi2O3–ZnO as a bifunctional nanomaterial

摘要

Heteroarchitectured Ag–Bi _(2) O _(3) –ZnO was synthesized through a simple, cost effective, template free photodeposition-hydrothermal method. This composite material represents a prospective new class of novel catalysts wherein the improved light absorption behavior of a metal doped coupled oxide, Ag–Bi _(2) O _(3) –ZnO is anticipated to enhance with the observed benefits of a coupled system of Bi _(2) O _(3) –ZnO. Characterization of Ag–Bi _(2) O _(3) –ZnO revealed interesting optical and morphological characteristics. XRD patterns indicated that well-crystallized α-Bi _(2) O _(3) was formed on the hexagonal wurtzite phase of ZnO along with Ag in the process. The HR-SEM images revealed the formation of organized intercrossed sheets and peanut shell like structure, which were composed of nanosheets and nanoparticles respectively. Elemental color mapping confirms the homogeneity of Zn, O, Ag and Bi in the catalyst. Ag–Bi _(2) O _(3) –ZnO has enhanced absorption in the UV and visible region when compared to Bi _(2) O _(3) and ZnO. This catalyst exhibited enhanced photocatalytic activity for the degradation of Acid Red 1 (AR 1), Evens Blue (EB) and Acid Violet 7 (AV 7) under natural sunlight far exceeding those of the Bi _(2) O _(3) , Ag–ZnO, Ag–Bi _(2) O _(3) and ZnO systems at neutral pH. Ag–Bi _(2) O _(3) –ZnO was found to be stable and reusable without appreciable loss of photocatalytic activity for up to five runs. Ag–Bi _(2) O _(3) –ZnO shows enhanced electrochemical methanol oxidation when compared to Ag–Bi _(2) O _(3) , Bi _(2) O _(3) –ZnO, Ag–ZnO and ZnO. Enhancement in methanol oxidation current demonstrates its high potential as an anode catalyst in direct methanol fuel cells.