skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Block copolymer-mediated synthesis of TiO2/RuO2 nanocomposite for efficient oxygen evolution reaction
Abstract An amphiphilic block copolymer, poly (styrene-2-polyvinyl pyridine-ethylene oxide), was used as a structure-directing and stabilizing agent to synthesize TiO2/RuO2nanocomposite. The strong interaction of polymers with metal precursors led to formation of a porous heterointerface of TiO2/RuO2. It acted as a bridge for electron transport, which can accelerate the water splitting reaction. Scanning electron microscopy, energy-dispersiveX-ray spectroscopy, transmission electron microscopy, andX-ray diffraction analysis of TiO2/RuO2samples revealed successful fabrication of TiO2/RuO2nanocomposites. The TiO2/RuO2nanocomposites were used to measure electrochemical water splitting in three-electrode systems in 0.1-M KOH. Electrochemical activities unveil that TiO2/RuO2-150 nanocomposites displayed superior oxygen evolution reaction activity, having a low overpotential of 260 mV with a Tafel slope of 80 mVdec−1. Graphical abstract  more » « less
Award ID(s):
2122067
PAR ID:
10562182
Author(s) / Creator(s):
; ;
Publisher / Repository:
Springer
Date Published:
Journal Name:
Journal of Materials Science
Volume:
59
Issue:
23
ISSN:
0022-2461
Page Range / eLocation ID:
10193 to 10206
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; ; ; et al (, Small)
    Abstract Development of high‐performance, low‐cost catalysts for electrochemical water splitting is key to sustainable hydrogen production. Herein, ultrafast synthesis of carbon‐supported ruthenium–copper (RuCu/C) nanocomposites is reported by magnetic induction heating, where the rapid Joule's heating of RuCl3and CuCl2at 200 A for 10 s produces Ru–Cl residues‐decorated Ru nanocrystals dispersed on a CuClxscaffold, featuring effective Ru to Cu charge transfer. Among the series, the RuCu/C‐3 sample exhibits the best activity in 1 mKOH toward both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with an overpotential of only −23 and +270 mV to reach 10 mA cm−2, respectively. When RuCu/C‐3 is used as bifunctional catalysts for electrochemical water splitting, a low cell voltage of 1.53 V is needed to produce 10 mA cm−2, markedly better than that with a mixture of commercial Pt/C+RuO2(1.59 V). In situ X‐ray absorption spectroscopy measurements show that the bifunctional activity is due to reduction of the Ru–Cl residues at low electrode potentials that enriches metallic Ru and oxidation at high electrode potentials that facilitates the formation of amorphous RuOx. These findings highlight the unique potential of MIH in the ultrafast synthesis of high‐performance catalysts for electrochemical water splitting. 
    more » « less
  2. ; (, European Journal of Inorganic Chemistry)
    Abstract A pair of novel Fe‐alkynyl complexes, [FeIII(HMTI)(C2SiEt3)2]ClO4(2) and [FeII(HMTI)(C2SiEt3)(NCCH3)]ClO4(3), is described herein. Reaction of Fe(meso‐HMC)Cl(ClO4)]ClO4(1) with lithiated triethylsilylacetylene and subsequent exposure to oxygen yielded the bis‐alkynyl2containing the dehydrogenated tetraimine macrocycle (HMTI). Reduction of2by mossy zinc in acetonitrile yielded the mono‐alkynyl3. The structures of2and3were determined using single‐crystal X‐ray diffraction. Analysis of visible absorption and electrochemical data establishes the redox‐active nature of the HMTI macrocycle, and indicates significant interactions between the Fedπ and tetraimine π* orbitals. These deductions are further supported by density functional theory calculations. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Advanced Energy Materials)
    Abstract Lithium/fluorinated graphite (Li/CFx) primary batteries show great promise for applications in a wide range of energy storage systems due to their high energy density (>2100 Wh kg–1) and low self‐discharge rate (<0.5% per year at 25 °C). While the electrochemical performance of the CFxcathode is indeed promising, the discharge reaction mechanism is not thoroughly understood to date. In this article, a multiscale investigation of the CFxdischarge mechanism is performed using a novel cathode structure to minimize the carbon and fluorine additives for precise cathode characterizations. Titration gas chromatography, X‐ray diffraction, Raman spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, cross‐sectional focused ion beam, high‐resolution transmission electron microscopy, and scanning transmission electron microscopy with electron energy loss spectroscopy are utilized to investigate this system. Results show no metallic lithium deposition or intercalation during the discharge reaction. Crystalline lithium fluoride particles uniformly distributed with <10 nm sizes into the CFxlayers, and carbon with lower sp2content similar to the hard‐carbon structure are the products during discharge. This work deepens the understanding of CFxas a high energy density cathode material and highlights the need for future investigations on primary battery materials to advance performance. 
    more » « less
  4. ; ; ; ; ; ; ; ; ; ; et al (, ChemSusChem)
    Abstract High‐efficiency and low‐cost catalysts for oxygen evolution reaction (OER) are critical for electrochemical water splitting to generate hydrogen, which is a clean fuel for sustainable energy conversion and storage. Among the emerging OER catalysts, transition metal dichalcogenides have exhibited superior activity compared to commercial standards such as RuO2, but inferior stability due to uncontrolled restructuring with OER. In this study, we create bimetallic sulfide catalysts by adapting the atomic ratio of Ni and Co in CoxNi1‐xSyelectrocatalysts to investigate the intricate restructuring processes. Surface‐sensitive X‐ray photoelectron spectroscopy and bulk‐sensitive X‐ray absorption spectroscopy confirmed the favorable restructuring of transition metal sulfide material following OER processes. Our results indicate that a small amount of Ni substitution can reshape the Co local electronic structure, which regulates the restructuring process to optimize the balance between OER activity and stability. This work represents a significant advancement in the development of efficient and noble metal‐free OER electrocatalysts through a doping‐regulated restructuring approach. 
    more » « less
  5. ; ; ; ; ; ; ; ; (, Angewandte Chemie International Edition)
    Abstract We report on the largest open‐shell graphenic bilayer and also the first example of triply negatively charged radical π‐dimer. Upon three‐electron reduction, bilayer nanographene fragment molecule (C96H24Ar6)2(Ar=2,6‐dimethylphenyl) (12) was transformed to a triply negatively charged species123.−, which has been characterized by single‐crystal X‐ray diffraction, electron paramagnetic resonance (EPR) spectroscopy and magnetic properties on a superconducting quantum interference device (SQUID).123.−features a 96‐center‐3‐electron (96c/3e) pancake bond with a doublet ground state, which can be thermally excited to a quartet state. It consists of 34 π‐fused rings with 96 conjugatedsp2carbon atoms. Spin frustration is observed with the frustration parameterf>31.8 at low temperatures in123.−, which indicates graphene upon reduction doping may behave as a quantum spin liquid. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email