Zhejiang Gongshang University

About: Zhejiang Gongshang University is a education organization based out in Hangzhou, China. It is known for research contribution in the topics: Computer science & Chemistry. The organization has 8258 authors who have published 7670 publications receiving 90296 citations. The organization is also known as: Zhèjiāng Gōngshāng Dàxué.

Fabrication of visible-light-active Bi/BiOI-Bi2O3 composite with enhanced photocatalytic activity

Abstract: Plasmonic Bi0 modified BiOI-Bi2O3 composite (Bi/BiOI-Bi2O3) was prepared via in situ UV reduction method. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) techniques were carried out to identify the formation of semimetal Bi0. The results indicated that the dot-like bismuth particles were originated from the partial reduction of lattice Bi3+ to Bi0 by accumulated conduction band electrons in BiOI-Bi2O3. The as-prepared ternary composite exhibited enhanced visible-light-response, decreased charge transfer impedance and higher charge carrier density relative to unmodified BiOI-Bi2O3. Due to synergistic effect between plasmonic Bi0 and BiOI-Bi2O3 heterojunction, dramatically enhanced photocatalytic activity for phenol degradation can be achieved. After 3.5 h visible light irradiation, the value for phenol removal efficiency was ca. 60% and 100% on BiOI-Bi2O3 and Bi/BiOI-Bi2O3, respectively. The calculated zero-order rate constant on Bi/BiOI-Bi2O3 was 1.7 and 3.9 times that on BiOI-Bi2O3 and Bi2O3, respectively. In addition to phenol, organic dyes (zwitterionic RhB, cationic MB and anionic Org II) were also used as model pollutants. Pronounced photocatalytic degradation by Bi/BiOI-Bi2O3 can be observed, further confirming the importance of Bi0. Trapping experiments using different scavengers indicated that photogenerated holes were major active species during the degradation of phenol. Furthermore, good stability was also observed in 5 successive cyclic runs. This study opens a new strategy for in situ preparation of plasmonic Bi0 modified composite.

Extortion can outperform generosity in the iterated prisoner's dilemma.

Abstract: Zero-determinant (ZD) strategies, as discovered by Press and Dyson, can enforce a linear relationship between a pair of players’ scores in the iterated prisoner’s dilemma. Particularly, the extortionate ZD strategies can enforce and exploit cooperation, providing a player with a score advantage, and consequently higher scores than those from either mutual cooperation or generous ZD strategies. In laboratory experiments in which human subjects were paired with computer co-players, we demonstrate that both the generous and the extortionate ZD strategies indeed enforce a unilateral control of the reward. When the experimental setting is sufficiently long and the computerized nature of the opponent is known to human subjects, the extortionate strategy outperforms the generous strategy. Human subjects’ cooperation rates when playing against extortionate and generous ZD strategies are similar after learning has occurred. More than half of extortionate strategists finally obtain an average score higher than that from mutual cooperation. The zero-determinant (ZD) strategies discovered by Press and Dyson overturned several decades of consensus about the iterated prisoner's dilemma. Here, the authors provide the first empirical evidence in support of Press and Dyson’s theory, by showing that knowledge of the opponent and the length of the interaction can facilitate the Generous and Extortionate ZD strategies as predicted.