Colloidal Synthesis of Plasmonic Ultrathin Transition-Metal Oxide Nanosheets

Recently, two-dimensional plasmonic ultrathin transition-metal oxide (TMO) nanosheets have attracted wide attention due to their unique properties. However, the colloidal preparation of these nanosheets with a strong plasmonic absorption and ultrathin nature at the same time still remains to be a great challenge. Herein, a general one-step colloidal method was used to fabricate ultrathin MO3-x (M = Mo or W) nanosheets by using H2MoO4 or H2WO4 as the raw material with the assistance of oleic acid (OA) and oleylamine (OAm). The obtained MO3-x nanosheets were derived from the topotactic phase transformation by the mediated effect of OA and OAm. These MO3-x nanosheets not only displayed intense plasmonic absorptions but also exhibited high specific surface areas (13.97 and 11.82 m(2) g(-1) for the as-prepared MoO3-x and MO3-x nanosheets, respectively). In addition, these MO3-x nanosheets also showed superior photocatalytic H-2 evolution performance through the dehydrogenation of ammonia borane under visible light irradiation. This work was expected to offer a new way for directly synthesizing ultrathin TMO nanosheets.