High-efficiently visible light-responsive photocatalysts: Ag3PO4 tetrahedral microcrystals with exposed {111} facets of high surface energy

National Basic Research Program of China [2011CBA00508, 2013CB933901]; National Natural Science Foundation of China [21333008, 21131005, 21021061, 21171141]In this article, single-crystalline tetrahedral Ag3PO4 microcrystals with exposed {111} facets was successfully synthesized via a facile wet chemical method. The tetrahedral Ag3PO4 with exposed {111} facets showed the highest photocatalytic activity in visible light irradiation among the {111}, {110} and {100} facets. By DFT calculations, it is demonstrated that the surface energy of the {111} facets is higher than that of the {110} and {100} facets. It was found that the largest band gap of the Ag3PO4 {111} surface is likely to suppress the recombination of electron-hole pairs by exploring the electronic structures of the different surfaces of Ag3PO4. Meanwhile, the dispersion between the valence bands and conduction bands of the {111} surface is beneficial for the separation of photogenerated electrons and holes on the {111} surface, which further improves the photocatalytic activity of the {111} surface

Room Temperature Lead-Free Multiaxial Inorganic-Organic Hybrid Ferroelectric.

In recent years, molecular ferroelectrics have received more and more attention. Nevertheless, the study of multiaxial molecular ferroelectrics is relatively rare, which significantly restricts the development of their applications in thin films and other potential fields. Here we demonstrate the characteristics of a room-temperature lead-free multiaxial inorganic-organic hybrid ferroelectric material [(CH3)2NH2] [C6H5CH2NH3]2BiBr6 ( 1 ), which goes through a distinctly reversible phase transition around 386 K and possesses six equivalent ferroelectric directions. At 330 K, the remnant polarization ( P r) of 1 is ∼1.0 μC·cm-2, and the coercive field ( E c) of 1 is 20 kV·cm-1. The multiaxial and switching polarization behaviors of 1 were declared with piezoresponse force microscopy (PFM). Notably, the emergence of six equivalent ferroelectric directions is induced by the easily disordered cations and highly geometrically symmetrical anions, because they usually lead to a large symmetry change in the order-disorder types of ferroelectrics. This work provides an effective approach to construct molecular multiaxial ferroelectrics

One-step synthesis of thermally stable artificial multienzyme cascade system for efficient enzymatic electrochemical detection

Abstract(#br)Recently, metal-organic framework (MOF)-based multienzyme systems integrating different functional natural enzymes and/or nanomaterial-based artificial enzymes are attracting increasing attention due to their high catalytic efficiency and promising application in sensing. Simple and controllable integration of enzymes or nanozymes within MOFs is crucial for achieving efficient cascade catalysis and high stability. Here, we report a facile electrochemical assisted biomimetic mineralization strategy to prepare an artificial multienzyme system for efficient electrochemical detection of biomolecules. By using the GO x @Cu-MOF/copper foam (GO x @Cu-MOF/CF) architecture as a proof of concept, efficient enzyme immobilization and cascade catalysis were achieved by in situ..

Tuning electronic structure of PdZn nanocatalyst via acid-etching strategy for highly selective and stable electrolytic nitrogen fixation under ambient conditions

Abstract(#br)Although ambient nitrogen fixation powered by renewable electricity is emerging as a highly attractive alternative to the classical Haber–Bosch process, it still remains extremely challenging. In this work, a facile acid-etching strategy was employed to synthesize defect-rich PdZn nanoparticles (NPs) supported on N-doped hollow carbon polyhedrons (etched-PdZn/NHCP), which could serve as an attractive and efficient electrocatalyst for the nitrogen reduction reaction (NRR). The synthesized etched-PdZn/NHCP electrocatalyst achieved higher NH 3 yields (5.28 μg mg -1 cat. h -1 ) than pristine PdZn NPs in a phosphate buffer solution. Remarkably, the existence of abundant defects in the etched PdZn NPs favored N 2 adsorption and activation, resulting in significantly high Faradaic efficiency (FE) of 16.9% towards NH 3 and outperforming previously reported Pd-based NRR electrocatalysts. Furthermore, the etched-PdZn/NHCP cathode exhibited good long-term electrochemical durability with both the NH 3 production and the FE remaining practically stable after 50 h of electrolysis

Facile synthesis of size-tunable ZIF-8 nanocrystals using reverse micelles as nanoreactors

电子邮件地址:[email protected] paper describes a robust method for the synthesis of high-quality ZIF-8 nanocrystals using reverse micelles as discrete nanoscale reactors. The precise size control of ZIF-8 nanocrystals is conveniently achieved by tuning the concentration of precursors, reaction temperatures, the amount of water, and the structure of surfactants. The as-synthesized ZIF-8 nanocrystals are of narrow distribution and tunable size. A size-dependent catalytic activity for Knoevenagel condensation reaction is further demonstrated by using ZIF-8 nanocrystals with different sizes as the catalysts. This facile method opens up a new opportunity in the synthesis of various ZIFs nanocrystals.Ministry of Science and Technology of China 2011CB932403 National Natural Science Foundation of China 21131005 21333008 20925103 2102106

One-step construction of ZnS/C and CdS/C one-dimensional core-shell nanostructures

ZnS/C and CdS/C coaxial core-shell nanowires, which consist of single-crystal semiconductor nanowires encapsulated by carbon nanotubes ( CNTs), have been synthesized by simple one-step thermal processes. These coaxial core-shell nanowires have uniform outer diameters ( 80-180 nm for ZnS/C, 60-130 nm for CdS/C), and uniform shell thicknesses ( ca. tens of nanometers) along their entire lengths up to tens of microns. The growth of the core-shell nanowires follows a novel metal reaction and self-catalysis vapor-liquid-solid ( VLS) mechanism. The simple method could, in principle, be extended to synthesize other metal sulfide single-crystal nanowire-filled carbon nanotubes, which can find potential applications in various fields of nanotechnology

N-doped carbon shell encapsulated PtZn intermetallic nanoparticles as highly efficient catalysts for fuel cells

Abstract(#br)The high cost and poor durability of Pt nanoparticles (NPs) have always been great challenges to the commercialization of proton exchange membrane fuel cells (PEMFCs). Pt-based intermetallic NPs with a highly ordered structure are considered as promising catalysts for PEMFCs due to their high catalytic activity and stability. Here, we reported a facile method to synthesize N-doped carbon encapsulated PtZn intermetallic (PtZn@NC) NPs via the pyrolysis of Pt@Zn-based zeolitic imidazolate framework-8 (Pt@ZIF-8) composites. The catalyst obtained at 800 °C (10%-PtZn@NC-800) was found to exhibit a half-wave potential ( E 1/2 ) up to 0.912 V versus reversible hydrogen electrode (RHE) for the cathodic oxygen reduction reaction in an acidic medium, which shifted by 26 mV positively..

Bromide-Induced Formation of a Highly Symmetric Silver Thiolate Cluster Containing 36 Silver Atoms from an Infinite Polymeric Silver Thiolate

通讯作者地址: Zheng, NF (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surface, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surface, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] to its good affinity with Ag+, Br- is able to truncate a silver thiolate polymer and induce the formation of a high-nuclearity silver thiolate nanocluster, [Br@Ag-36(SC(6)H(4)tBu-4)(36)](-) The nanocluster has a disc-like structure with one Br- anion trapped at the center of the cluster in an octahedral coordination.National Natural Science Foundation of China 20871100,20721001,20925103 Natural Science Foundation of Fujian 2009 J06005 Key Scientific Project of Fujian Province 2009HZ0002-

Formaldehyde-assisted synthesis of ultrathin Rh nanosheets for applications in CO oxidation

National Basic Research Program of China [2011CBA00508]; National Natural Science Foundation of China [21171142]; program for New Century Excellent Talents in University [NCET-11-0294]; Fundamental Research Funds for the Central UniversitiesUltrathin Rh nanosheets with a thickness of approximately 1 nm were synthesized via a simple surfactant-free hydrothermal route, using Rh(II) acetylacetonate as the precursor and formaldehyde as the shape controller. CO and H-2 originating from the formaldehyde decomposition played key roles in the formation of ultrathin Rh nanosheets