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 & Microstructure. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

Guiding Transition Metal‐Doped Hollow Cerium Tandem Nanozymes with Elaborately Regulated Multi‐Enzymatic Activities for Intensive Chemodynamic Therapy

Abstract: Clinical applications of nanozyme-initiated chemodynamic therapy (NCDT) have been severely limited by the poor catalytic efficiency of nanozymes, insufficient endogenous hydrogen peroxide (H2 O2 ) content, and its off-target consumption. Herein, the authors developed a hollow mesoporous Mn/Zr-co-doped CeO2 tandem nanozyme (PHMZCO-AT) with regulated multi-enzymatic activities, that is, the enhancement of superoxide dismutase (SOD)-like and peroxidase (POD)-like activities and inhibition of catalase (CAT)-like activity. PHMZCO-AT as a H2 O2 homeostasis disruptor promotes H2 O2 evolution and restrains off-target elimination of H2 O2 to achieve intensive NCDT. PHMZCO-AT with SOD-like activity catalyzes endogenous superoxide anion (O2•- ) into H2 O2 in the tumor region. The suppression of CAT activity and depletion of glutathione by PHMZCO-AT largely weaken the off-target decomposition of H2 O2 to H2 O. Elevated H2 O2 is then catalyzed by the downstream POD-like activity of PHMZCO-AT to generate toxic hydroxyl radicals, further inducing tumor apoptosis and death. T1 -weighted magnetic resonance imaging and X-ray computed tomography imaging are also achieved using PHMZCO-AT due to the existence of paramagnetic Mn2+ and the high X-ray attenuation ability of elemental Zr, permitting in vivo tracking of the therapeutic process. This work presents a typical paradigm to achieve intensive NCDT efficacy by regulating multi-enzymatic activities of nanozymes to perturb the H2 O2 homeostasis.

A highly active，stable and synergistic Pt nanoparticles/Mo2C nanotube catalyst for methanol electro-oxidation

Abstract: Poor electrocatalytic activity and carbon monoxide (CO) poisoning of the anode in Pt-based catalysts are still two major challenges facing direct methanol fuel cells. Herein, we demonstrate a highly active and stable Pt nanoparticle/Mo2C nanotube catalyst for methanol electro-oxidation. Pt nanoparticles were deposited on Mo2C nanotubes using a controllable atomic layer deposition (ALD) technique. This catalyst showed much higher catalytic activity for methanol oxidation and superior CO tolerance, when compared with those of the conventional Pt/C and PtRu/C catalysts. The experimental evidence from X-ray absorption near-edge structure spectroscopy and scanning transmission X-ray microscopy clearly support a strong chemical interaction between the Pt nanoparticles and Mo2C nanotubes. Our studies show that the existence of Mo2C not only minimizes the required Pt usage but also significantly enhances CO tolerance and thus improves their durability. These results provide a promising strategy for the design of highly active next-generation catalysts. Platinum nanoparticles on Mo2C nanotubesact as a stable, highly active catalyst for methanol electro-oxidation, find a binational team led by Chunwen Sun from Institute of Physics, Chinese Academy of Sciences. Methanol electro-oxidation is a critical reaction in direct methanol fuel cells, but conventional methods for catalysing it using Pt-based catalysts loaded on carbon suffer from low activities and CO poisoning of the anode. Now, researchers in China and Canada have discovered that a catalyst produced by depositing Pt nanoparticles on Mo2C nanotubes by controlled atomic layer deposition can overcome both problems. Based on X-ray spectroscopy and microscopy measurements, they attribute this to synergistic effects between the two components. Their results reveal that the presence of Mo2C both reduces the amount of Pt needed (thus lowering costs) and enhances CO tolerance (thereby improving durability), indicating that it is a promising strategy for designing highly active next-generation catalysts. In this paper, we demonstrate a highly active and stable Pt nanoparticle/Mo2C nanotube catalyst for methanol electro-oxidation. Well-dispersed Pt nanoparticles were deposited on Mo2C nanotubes using a controllable atomic layer deposition (ALD) technique. This catalyst showed much higher catalytic activity for methanol oxidation and superior CO tolerance, when compared with those of the conventional Pt/C and PtRu/C catalysts. These results provide a promising strategy for the design of highly active next-generation catalysts.

Self-supported N-doped CNT arrays for flexible Zn–air batteries

Abstract: The exploitation of flexible and rechargeable energy storage devices is crucial for meeting the requirements of the next generation of electronic products. Herein, we report a novel method to grow N-doped carbon nanotube (NCNT) arrays with encapsulated CoFe alloy nanoparticles on carbon fiber cloth (CFC) as a self-supported air cathode for flexible ZABs. The optimized electrode exhibits superior bifunctional activities with a half-wave potential of 0.873 V for the oxygen reduction reaction (ORR) and a potential of 1.506 V for the oxygen evolution reaction (OER) at 10 mA cm−2, greatly superior to that of 20% Pt/C for the ORR and IrO2 for the OER, respectively. The experimental results demonstrate that the atomically dispersed Co(Fe) dual-sites formed in the NCNT walls are key to the excellent activities of the self-supported electrode. When the self-supported electrode is applied as an air cathode for flexible solid-state ZABs, a large open-circuit voltage of 1.426 V, a high initial energy efficiency of 69% and a large power density of 37.7 mW cm−2 as well as robust stability are achieved. Furthermore, the solid-state ZABs with the self-supported electrode exhibit excellent flexibility even under extreme bending conditions. Our strategy presented here opens a new way for bifunctional catalysts for high-performance flexible ZABs.