3 years ago

Facilitated photoinduced electron storage and two-electron reduction of oxygen by reduced graphene oxide in rGO/TiO2/WO3 composites

Facilitated photoinduced electron storage and two-electron reduction of oxygen by reduced graphene oxide in rGO/TiO2/WO3 composites
A triple-component composite (GTW) comprising of reduced graphene oxide (rGO), TiO2 and WO3 was studied for the photoinduced electron storage and release. The composite was assembled through a one-step hydrothermal method using graphene oxide (GO), TiO2 and peroxotungstic acid as the precursors. The crystal structure and morphology of the composites were characterized by X-ray diffraction (XRD) and high resolution-transmission electron microscopy (HRTEM), respectively. Monolithic WO3 nanoplates and mixture phase TiO2 nanoparticles were dispersed over the surface of rGO nanosheets. The photocharge and discharge tests and the reduction of Cr(VI) and H2O2 by the stored electrons were carried out. Compared to the composite in the absence of rGO, the composite GTW displayed a ten times higher electron storage capacity (∼115C/g) and a much faster charging rate (8min less charging time to reach balanced EOC); and electrons stored in GTW achieved 17% more Cr(VI) reduction efficiency and 65% higher H2O2 reduction rate. Two electron reduction of oxygen by the stored photoinduced electrons was indicated by the generation of H2O2. The highest H2O2 concentration reached 39.6μM during the oxygen reduction for the composite with rGO, while no H2O2 was detected for the samples in the absence of rGO. Accompanied with the enhanced electrochemical oxygen reduction reaction and chemically adsorbed O2 on the composite, the critical roles of rGO as an electron mediator to facilitate interfacial charge transfer, as the electron container to improve electron storage capacity, and as a promoter for two-electron reduction of O2 were established.

Publisher URL: www.sciencedirect.com/science

DOI: S0013468617316900

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.