Designing interstitial boron-doped tunnel-type vanadium dioxide cathode for enhancing zinc ion storage capability

Chemical doping is a powerful method to intrinsically tailor the electrochemical properties of electrode materials.Here,an interstitial boron-doped tunnel-type VO_(2)(B)is constructed via a facile hydrothermal method.Various analysis techniques demonstrate that boron resides in the interstitial site of VO_(2)(B)and such interstitial doping can boost the zinc storage kinetics and structural stability of VO_(2)(B)cathode during cycling.Interestingly,we found that the boron doping level has a saturation limit peculiarity as proved by the quantitative analysis.Notably,the 2 at.%boron-doped VO_(2)(B)shows enhanced zinc ion storage performance with a high storage capacity of 281.7 mAh g^(-1) at 0.1 A g^(-1),excellent rate performance of 142.2 mAh g^(-1) at 20 A g^(-1),and long cycle stability up to 1000 cycles with the capacity retention of 133.3 mAh g^(-1) at 5 A g^(-1).Additionally,the successful preparation of the boron-doped tunneltype α-MnO_(2) further indicates that the interstitial boron doping approach is a general strategy,which supplies a new chance to design other types of functional electrode materials for multivalence batteries.

Imine-Linked Covalent Organic Framework on Surface for Biosensor

Imine-linked covalent organic framework on amino functionalized silicon substrate was constructed via a step-wise reaction between 1,3,5-benzenetricarboxaldehyde and 1,4-diaminobenzene.The obtained material was used as biosensor for bovine serum albumin(BSA)adsorption and probe DNA immobilization,which extended the application of covalent organic frameworks(COFs)to a new field.

NH_(4)Cl-assisted preparation of single Ni sites anchored carbon nanosheet catalysts for highly efficient carbon dioxide electroreduction

Single-atomic transition metal-nitrogen codoped carbon(M-N-C)are efficient substitute catalysts for noble metals to catalyze the electrochemical CO_(2) reduction reaction(CO_(2)RR).However,the uncontrolled aggregations of metal and serious loss of nitrogen species constituting the M-N_(x) active sites are frequently observed in the commonly used pyrolysis procedure.Herein,single-atomic nickel(Ni)-based sheet-like electrocatalysts with abundant Ni-N_(4) active sites were created by using a novel ammonium chloride(NH_(4)Cl)-assited pyrolysis method.Spherical aberration correction electron microscopy and X-ray absorption fine structure analysis clearly revealed that Ni species are atomically dispersed and anchored by N in Ni-N_(4) structure.The addition of NH_(4)Cl optimized the mesopore size to 7-10 nm and increased the concentrations of pyridinic N(3.54 wt%)and Ni-N_(4)(3.33 wt%)species.The synergistic catalytic effect derived from Ni-N_(4) active sites and pyridinic N species achieved an outstanding CO_(2) RR performance,presenting a high CO Faradaic efficiency(FE_(CO))up to 98% and a large CO partial current density of 8.5 mA cm^(-2) at a low potential of-0.62 V vs.RHE.Particularly,the FE_(CO) maintains above 80% within a large potential range from -0.43 to -0.73 V vs.RHE.This work provides a practical and feasible approach to building highly active single-atomic catalysts for CO_(2) conversion systems.

Highly Sensitive Functionalized Conducting Copolypyrrole Film for DNA Sensing and Protein-resistant

In order to exploit the applications ofpolypyrrole （PPy） derivatives in biosensors and bioelectronics, the different immobilization mechanisms of biomolecules onto differently functionalized conducting PPy films are investigated. Pyrrole and pyrrole derivatives with carboxyl and amino groups were copolymerized with ω-（N-pyrrolyl）-octylthiol self-assembled on Au surface by the method of the chemical polymerization to form a layer of the copolymer film, i.e., poly[pyrrole-co-（N-pyrrolyl）-caproic acid] （poly（Py-co-PyCA）） and poly[pyrrole-co-（N-pyrrolyl）-hexylamine] （poly（Py-co-PyHA））, in which the carboxyl groups in poly（Py-co-PyCA） were activated to the ester groups. Based on the structure characteristics, the immobilization/hybridization of DNA molecules on PPy, poly（Py-co-PyCA） and poly（Py-co-PyHA） were surveyed by cyclic voltammograms measurements. For differently functionalized copolymers, the immobilization mechanisms of DNA are various. Besides the electrochemical properties of the composite electrodes of PPy and its copolymers being detected before and after bovine serum albumin （BSA） adsorption, the kinetic process of protein binding was determined by surface plasmon resonance of spectroscopy. Since few BSA molecules could anchor onto the PPy and its copolymers surfaces, it suggests this kind of conducting polymers can be applied as the protein-resistant material.

Nanoreactors derived from silica-protection-assisted metal-organic framework

The construction of highly stable and regular nanoreactors is a major challenge.In this work,we use a facile template protection method to obtain ZIF-67@SiO2(JS) and to encapsulate metal oxide nanoparticles(Co3O4) into nanoreactors(SiO2).ZIF-67 crystals provide a cobalt species;SiO2 was first used as a protective layer of ZIF-67 and then as a nanoreactor for metastable metal oxide nanoparticles.On this basis,Co3O4@SiO2 with dodecahedron morphology were synthesized by calcining JS at different tempe ratures,followed by a hydrothermal reaction to obtain Co3(OH)4Si2O5.Subsequently,CoSx and CoP-SiO2 were fabricated through sulfuration and phosphorization.The results in this work show that nanoreactors derived from metal-organic frameworks(MOFs) with a rational structure have broad development prospects.

Morphology and size controlled synthesis of Co-doped MIL-96 by different alkaline modulators for sensitively detecting alpha-fetoprotein

This work introduces a simple and facile approach for the morphology and size controlled synthesis of Co-doped MIL-96.By using different bases as modulators,Co-doped MIL-96 was obtained with sizes that varied from 5 μm to 300 nm,and four different morphologies,including hexagonal prism,icosahedron,hexagonal spindle and ellipsoid.Among these,nano-sized Co-doped MIL-96 with an ellipsoid morphology exhibited the highest electroactive surface area and good conductivity as well as the best electrochemical sensing performance towards α-fetoprotein.