Improved Photocatalytic Performance of TiO2-Nitrogen-Doped Graphene Quantum Dot Composites Mediated by Heterogeneous Interactions

Mark P Croxall; Reece T Lawrence; Rajshree Ghosh Biswas; Ronald Soong; Andre J Simpson; M Cynthia Goh

doi:10.1021/acs.jpclett.4c00335

Improved Photocatalytic Performance of TiO₂-Nitrogen-Doped Graphene Quantum Dot Composites Mediated by Heterogeneous Interactions

J Phys Chem Lett. 2024 Apr 4;15(13):3653-3657. doi: 10.1021/acs.jpclett.4c00335. Epub 2024 Mar 26.

Authors

Mark P Croxall¹, Reece T Lawrence^{1

2}, Rajshree Ghosh Biswas^{1

3}, Ronald Soong³, Andre J Simpson^{1

3}, M Cynthia Goh^{1

2}

Affiliations

¹ Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
² Department of Materials Science and Engineering, University of Toronto, Toronto, ON M5S 3E4, Canada.
³ Department of Physical and Environmental Science, University of Toronto, Toronto, ON M1C 1A4, Canada.

PMID: 38531047
PMCID: PMC11000646 (available on 2025-03-26)
DOI: 10.1021/acs.jpclett.4c00335

Abstract

Photocatalysis is typically monitored via analysis of phases in isolation and focuses on the removal of a target analyte from the solution phase. Here we analyze the photocatalytic action of a TiO₂-nitrogen-doped graphene quantum dot (NGQD) composite on a target analyte, phenol, using comprehensive multiphase NMR (CMP-NMR) which observes signals in solid, solution, and gel phases in situ. Phenol preferentially interacts with the composite photocatalyst compared to pure TiO₂, increasing its effective concentration near the catalyst surface and its degradation rate. The presence of NGQDs in the composite reduced the fouling of the catalyst surface and caused a reduction of photogenerated intermediates. Increased heterogeneous interactions, likely mediated by π-π interactions, are hypothesized to cause each of these improvements in the observed photocatalytic performance by TiO₂-NGQDs. CMP-NMR allows the elucidation of how the photocatalytic mechanism is enhanced via material design and provides a foundation for the development of efficient photocatalysts.