3 years ago

Sensitization of Pt/TiO2 Using Plasmonic Au Nanoparticles for Hydrogen Evolution under Visible-Light Irradiation

Sensitization of Pt/TiO2 Using Plasmonic Au Nanoparticles for Hydrogen Evolution under Visible-Light Irradiation
Rose Amal, Jie Hui Ho, Roong Jien Wong, Yijiao Jiang, Fenglong Wang
Au nanoparticles with different sizes (10, 20, 30, and 50 nm) were synthesized using a seed-assisted approach and anchored onto Pt/TiO2 employing 3-mercaptopropionic acid as the organic linker. The sizes of the Au nanoparticles were controlled within a narrow range so that the size-dependent surface plasmonic resonance effect on sensitizing Pt/TiO2 can be thoroughly studied. We found that 20 nm Au nanoparticles (Au20) gave the best performance in sensitizing Pt/TiO2 to generate H2 under visible-light illumination. Photoelectrochemical measurements indicated that Au20-Pt/TiO2 exhibited the most efficient “hot” electrons separation among the studied catalysts, correlating well with the photocatalytic activity. The superior performance of Au-supported Pt/TiO2 (Au20-Pt/TiO2) compared with Au anchored to TiO2 (Au20/TiO2) revealed the important role of Pt as a cocatalyst for proton reduction. To elucidate how the visible-light excited hot electrons in Au nanoparticles involved in the proton-reduction reaction process, Au20/TiO2 was irradiated by visible light (λ > 420 nm) with the presence of Pt precursor (H2PtCl6) in a methanol aqueous solution under deaerated condition. Energy-dispersive X-ray spectroscopy mapping analysis on the recovered sample showed that Pt ions could be reduced on the surfaces of both Au nanoparticles and TiO2 support. This observation indicated that the generated hot electrons on Au nanoparticles were injected into the TiO2 conduction band, which were then subsequently transferred to Pt nanoparticles where proton reduction proceeded. Besides, the excited hot electrons could also participate in the proton reduction on Au nanoparticles surface.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b06265

DOI: 10.1021/acsami.7b06265

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.