Constructing the Pd/PdO/β‐Bi2O3 microspheres with enhanced photocatalytic activity for Bisphenol A degradation and NO removal

Abstract

AbstractBACKGROUNDPhotocatalysis is one of the effective ways to solve the problem of water and gas pollution. An excellent photocatalyst should have the following advantages: efficient photocatalytic activity for gas and water pollutants, recyclable and stable characteristics, non‐toxic and low‐cost. Constructing heterojunctions and introducing oxygen vacancies (OVs) are two effective measures to achieve these targets.RESULTSIt is found that the 1.0% Pd/PdO/β‐Bi2O3 exhibits the best photocatalytic activity with an efficiency of 97.4% for Bisphenol A (BPA) degradation and 47.6% for nitric oxide (NO) removal within 30 min. The 1.0% Pd/PdO/β‐Bi2O3 composite shows 23.3% efficiency in the photodegradation of BPA under 595 nm monochromatic light irradiation, while β‐Bi2O3 tends to be invalid. Moreover, the OVs promote the removal of NO without irradiation.CONCLUSIONIn this work, a novel ternary Pd/PdO/β‐Bi2O3 material as high‐performance photocatalyst for the BPA degradation and NO removal was synthesized. The presence of OVs promotes the activation of the oxygen molecule, thereby facilitating the photocatalytic process. The p‐n junction of PdO/β‐Bi2O3 and the Schottky barrier of Pd/β‐Bi2O3 significantly limit the recombination of photoinduced electron–hole pairs in the composite. Furthermore, an artifact in the electron spin resonance (ESR) spectrum obtained by spin trapping with 5,5‐dimethyl‐1‐pyrroline N‐oxide (DMPO) as adducts confirms that both hydroxyl radical (•OH) and superoxide radical (•O2−) species are involved in the photocatalytic process. The present work offers a new perspective for developing the composite photocatalysts with high efficiency through loading of metal nanoparticles and creating an heterojunction. © 2019 Society of Chemical Industry