Realizing High Capacitance and Rate Capability in Polyaniline by Enhancing the Electrochemical Surface Area through Induction of Superhydrophilicity.

Polyaniline (PANI) as a pseudocapacitive material has very high theoretical capacitance of 2000 F g. However, its practical capacitance has been limited by low electrochemical surface area (ESA) and unfavorable wettability toward aqueous electrolytes. This work deals with a strategy wherein the high ESA of PANI has been achieved by the induction of superhydrophilicity together with the alignment of PANI exclusively on the surface of carbon fibers as a thin layer to form a hybrid assembly.

Room-Temperature Activation of CO by Dual Defect-Stabilized Nanoscale Hematite (FeO ): Concurrent Role of Fe and O Vacancies.

We demonstrate that synthetically controlled concurrent stabilization of Fe and O vacancy defects on the surface of interbraided nanoscale hematite (FeO ) renders an interesting surface chemistry which can reduce CO to CO at room temperature (RT). Importantly, we realized a highly enhanced output of 410 μmol h g at RT, as compared to that of 10 μmol h g for bulk hematite. It is argued based on the activity degradation under cycling and first principles density functional theory calculations that the excess chemical energy embedded in the defect-stabilized surface is expended in this high-energy conversion process, which leads to progressive filling up of oxygen vacancies.