Harbin Engineering University

About: Harbin Engineering University is a education organization based out in Harbin, Heilongjiang, China. It is known for research contribution in the topics: Control theory & Computer science. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

Two-Dimensional Porous Molybdenum Phosphide/Nitride Heterojunction Nanosheets for pH-Universal Hydrogen Evolution Reaction

Abstract: Herein, we present a new strategy for the synthesis of 2D porous MoP/Mo2 N heterojunction nanosheets based on the pyrolysis of 2D [PMo12 O40 ]3- -melamine (PMo12 -MA) nanosheet precursor from a polyethylene glycol (PEG)-mediated assembly route. The heterostructure nanosheets are ca. 20 nm thick and have plentiful pores ( 55 mA cm-2 in neutral medium and >190 mA cm-2 in alkaline medium.

Hybrid metamaterial switching for manipulating chirality based on VO2 phase transition

Abstract: Polarization manipulations of electromagnetic waves can be obtained by chiral and anisotropic metamaterials routinely, but the dynamic and high-efficiency modulations of chiral properties still remain challenging at the terahertz range. Here, we theoretically demonstrate a new scheme for realizing thermal-controlled chirality using a hybrid terahertz metamaterial with embedded vanadium dioxide (VO2) films. The phase transition of VO2 films in 90° twisted E-shaped resonators enables high-efficiency thermal modulation of linear polarization conversion. The asymmetric transmission of linearly polarized wave and circular dichroism simultaneously exhibit a pronounced switching effect dictated by temperature-controlled conductivity of VO2 inclusions. The proposed hybrid metamaterial design opens exciting possibilities to achieve dynamic modulation of terahertz waves and further develop tunable terahertz polarization devices.

Functional Pillared Graphene Frameworks for Ultrahigh Volumetric Performance Supercapacitors

Abstract: Supercapacitors, also known as electrochemical capacitors, can provide much faster charge–discharge, greater power density, and cyclability than batteries, but they are still limited by lower energy densities (or the amount of energy stored per unit volume). Here, a novel strategy for the synthesis of functional pillared graphene frameworks, in which graphene fragments in-between graphene sheets, through simple thermal-treatment of ozone (O3)-treated graphene oxide at very low temperature of 200 °C is reported. Due to its high packing density, high content of stable oxygen species, and continues ion transport network in-between graphene sheets, the functional pillared-graphene framework delivers not only high gravimetric capacitance (353 F g−1 based on the mass of the active material) and ultrahigh volumetric capacitance (400 F cm−3 based on total mass of electrode material) in aqueous electrolyte but also excellent cyclic stability with 104% of its initial capacitance retention after 10 000 cycles. Moreover, the assembled symmetric supercapacitor achieves as high as 27 Wh L−1 of volumetric energy density at a power density of 272 W L−1. This novel strategy holds great promise for future design of high volumetric capacitance supercapacitors.

Bubble‐Decorated Honeycomb‐Like Graphene Film as Ultrahigh Sensitivity Pressure Sensors

Abstract: A flexible, bubble‐decorated, honeycomb‐like graphene film (BHGF) is fabricated by a low‐temperature heat treatment of graphene oxide film. The as‐prepared BHGF exhibits an ultrahigh sensitivity of 161.6 kPa−1 at a strain less than 4%, due to the switching effect depended on “point‐to‐point” and “point‐to‐face” contact modes.

Molybdenum carbide nanocrystal embedded N-doped carbon nanotubes as electrocatalysts for hydrogen generation

Abstract: N-doped carbon nanotubes embedded with molybdenum carbide nanocrystals with a size less than 3 nm were fabricated. Due to their small size, tubular characteristics and high conductivity, the hybrid nanotubes exhibit superior activity for the hydrogen evolution reaction, including small overpotential, large cathodic current density and high exchange current density.