Bridging Gaps in the Synthesis of g-CN/WO<sub>3-<i>x</i> </sub> for Photocatalytic H<sub>2</sub>O<sub>2</sub> Generation: Insights into S-Scheme Heterojunction and Plasmon-Induced Hot Electrons

Basak A., Ozer M. S., Eroglu Z., Sun K., Metin O.

LANGMUIR, cilt.41, sa.21, ss.13381-13394, 2025 (SCI-Expanded, Scopus) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 41 Sayı: 21
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1021/acs.langmuir.5c01154
  • Dergi Adı: LANGMUIR
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, MEDLINE
  • Sayfa Sayıları: ss.13381-13394
  • Kocaeli Üniversitesi Adresli: Evet

Özet

This study presents a systematic design for fabricating g-CN/WO3-x S-scheme heterojunctions with plasmonic features (localized surface plasmon resonance (LSPR) and hot electrons) to achieve superb photocatalytic H2O2 production activity. To optimize the synthesis, a rational approach is employed to how synthesis parameters influence the emergence of LSPR and hot electrons in WO3-x and their effect on the heterojunction's performance. As a result of such a comprehensive strategy, the developed synthesis methodology effectively bridges gaps in the literature, addressing underexplored strategies for improving photocatalytic efficiency for the controlled synthesis of the g-CN/WO3-x heterojunction. The plasmonic characteristics attributed to oxygen deficiency in WO3 (WO3-x ) and g-CN/WO3-x and interactions of g-CN and WO3-x at the atomic level are further corroborated through a comprehensive analysis employing X-ray photoelectron spectroscopy (XPS), solid-state nuclear magnetic resonance (ssNMR), and electron paramagnetic resonance (EPR). Thanks to the presence of WO3-x , the light-harvesting ability of g-CN/WO3-x heterojunctions spans from the visible to near-infrared region. Moreover, the generation of hot electrons on the surface of WO3-x mitigates electron-hole recombination in the binary heterojunction. Consequently, the g-CN/WO3-x S-scheme heterojunctions synthesized with the optimal recipe provided a superior photocatalytic H2O2 generation rate of 1349.70 mu molL-1 in 10% (v/v) aqueous methanol solution within 90 min, which is 2.36 and 7.17 times greater than that of pristine g-CN and WO3-x , respectively, superior to other similar photocatalysts tested in photocatalytic H2O2 production. The superb photocatalytic activity of the g-CN/WO3-x heterojunction is attributed to the synergistic effects aroused in the S-scheme heterojunction, promoting efficient charge separation with enhanced redox potentials and plasmon-induced hot electrons that both accelerate reactions through the photothermal effect and serve as additional reducing species. This research broadens the perspective toward constructing nonmetallic plasmonic S-scheme heterojunctions for fields utilizing LSPR phenomena, such as photocatalysis, photonics, and biomedicine.