University of Science and Technology Beijing

About: University of Science and Technology Beijing is a education organization based out in Beijing, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 41558 authors who have published 44473 publications receiving 623229 citations. The organization is also known as: Beijing Steel and Iron Institute.

Bi2O2(OH)(NO3) as a desirable [Bi2O2]2+ layered photocatalyst: strong intrinsic polarity, rational band structure and {001} active facets co-beneficial for robust photooxidation capability

Abstract: Developing high-performance photocatalytic materials is of huge significance and highly desirable for fulfilling the pressing need in environmental remediation. In this work, we demonstrate the use of bismuth nitrate Bi2O2(OH)(NO3) as an absorbing photocatalyst, which integrates multiple superiorities, like a [Bi2O2]2+ layered configuration, a non-centrosymmetric (NCS) polar structure and highly reactive {001} facets. Bi2O2(OH)(NO3) nanosheets are obtained by a facile one-pot hydrothermal route using Bi(NO3)3·5H2O as the sole raw material. Photocatalysis assessment revealed that Bi2O2(OH)(NO3) holds an unprecedented photooxidation ability in contaminant decomposition, far out-performing the well-known photocatalysts BiPO4, Bi2O2CO3, BiOCl and P25 (commercial TiO2). Particularly, it displays a universally powerful catalytic activity against various stubborn industrial contaminants and pharmaceuticals, including phenol, bisphenol A, 2,4-dichlorophenol and tetracycline hydrochloride. In-depth experimental and density functional theory (DFT) investigations co-uncovered that the manifold advantages, such as large polarizability and rational band structure, as well as exposed {001} active facets, induced robust generation of strong oxidating superoxide radicals (˙O2−) in the conduction band and hydroxyl radicals (˙OH) in the valence band, thus enabling Bi2O2(OH)(NO3) to have a powerful and durable photooxidation capability. Bi2O2(OH)(NO3) also presents high photochemical stability. This work not only rendered a highly active and stable photocatalyst for practical applications, but also laid a solid foundation for future initiatives aimed at designing new photoelectronic materials by manipulating multiple advantageous factors.

Bond Order Analysis Based on the Laplacian of Electron Density in Fuzzy Overlap Space

Abstract: Bond order is an important concept for understanding the nature of a chemical bond. In this work, we propose a novel definition of bond order, called the Laplacian bond order (LBO), which is defined as a scaled integral of negative parts of the Laplacian of electron density in fuzzy overlap space. Many remarkable features of LBO are exemplified by numerous structurally diverse molecules. It is shown that LBO has a direct correlation with the bond polarity, the bond dissociation energy, and the bond vibrational frequency. The dissociation behavior of LBO of the N–N bond in N2 has been studied. Effects of the basis sets, theoretic methods, and geometrical conformations on LBO have also been investigated. Through comparisons, we discussed in details similarities and discrepancies among LBO, Mayer bond order, natural localized molecular orbital bond order, fuzzy overlap population, and electron density at bond critical points.