Complex Energy Materials – Making Sense of All the Points
Jan 30, 2026
2:30PM to 3:30PM
Date/Time
Date(s) - 30/01/2026
2:30 pm - 3:30 pm
Categories
Prof. Robert Godin
Department of Chemistry, University of British Columbia
Polymeric photocatalysts made of Earth-abundant elements have been extensively developed over the past decade to take advantage of their synthetic tunability.1 Within this family, carbon nitrides (CNx) are emerging as leading photocatalysts because of their high photocatalytic performance combined with good stability and facile synthesis.2 However, significant gaps remain in our knowledge of the photophysical properties of these organic polymeric materials. Determining the pathways and mechanism of photoinduced processes will greatly aid our efforts to engineer better CNx photocatalysts for solar fuel production, environmental remediation, and synthetic photochemistry.3
Since the discovery in 2009 that CNx has substantial photocatalytic activity for H2 production,4 the typical optimization approach has been to do a detailed structural analysis of a small set of samples and try to rationalize the improvements in photocatalytic activity. While this has led to broad improvements in CNx performance over the years, there still lacks a complete understanding of how the synthetic conditions need to be optimized. There is still no holistic principle that guides how one can optimize the synthetic conditions. This motivates us to devise 1) new tools to access richer information and 2) promote new approaches of analyzing the information at hand.
We have developed a first-of-its-kind transient absorption microscopy (TAM) system that can monitor charge carrier dynamics on the microsecond – second timescales together with spatial resolution on the micron scale. Spatial mapping of the charge carrier dynamics with this system provides novel insights into the particle-to-particle heterogeneity and heterogeneity within individual CNx particles.5 Our observations point to the presence of at least two different types of trap states that dictate the density of trapped charges and the charge carrier lifetime, respectively, and preferential siting of cocatalysts on the surface of CNx.6
The vast chemical space for CNx synthesis makes it challenging to obtain holistic insights into the key parameters that dictate its photocatalytic activity. To extract insights into the link between synthetic parameters and the activity of the CNx materials, we have turned to three different multivariate approaches, namely Pearson correlation, Principal Component Analysis (PCA), and machine-learning models. These help us analyze datasets built from the materials’ synthetic and characterization information to yield what features have the most significant impact on the photocatalytic activity. These approaches have helped us determine that opto-electronic properties are more predictive of photocatalytic performance than structural properties, and that studying trapping phenomena in the ?s-s timescale is key for understanding the discrepancies in HER performances arising from subtle electronic differences in disordered polymeric CNx
1 Y. Wang, A. Vogel, M. Sachs, R. S. Sprick, L. Wilbraham, S. J. A. Moniz, R. Godin, M. A. Zwijnenburg, J. R. Durrant, A. I. Cooper and J. Tang, Nat. Energy, 2019, 4, 746–760.
2 P. O. Ohemeng and R. Godin, Sustainable Energy Fuels, 2023, 7, 3250–3265.
3 R. Godin and J. R. Durrant, Chem. Soc. Rev., 2021, 50, 13372–13409.
4 X. Wang, K. Maeda, A. Thomas, K. Takanabe, G. Xin, J. M. Carlsson, K. Domen and M. Antonietti, Nat. Mater., 2009, 8, 76–80.
5 S. Khasnabis and R. Godin, Small, 2024, 21, 2406652.
6 S. Khasnabis, M. Cassandra and R. Godin, ChemSusChem, 2025, 18, e202500203.
Bio
Dr. Robert Godin established the SolarSpec group (Solar Energy Conversion and Spectroscopy) in 2018 at UBC Okanagan in Kelowna, British Columbia, Canada. The group develops time-resolved spectroscopic tools to better understand carbon-based semiconductors for sustainable energy production, with a healthy dose of physical organic chemistry concepts. Born in Bathurst, New Brunswick, Robert has fostered an interest in photochemistry since the start of his higher education career. He first got introduced to photochemistry and spectroscopy techniques working with Prof. Tito Scaiano during his B.Sc. at the University of Ottawa. He continued to learn advanced optical techniques with Prof. Gonzalo Cosa during his Ph.D. on single molecule spectroscopy at McGill University. Robert then completed a FRQNT-funded postdoctoral stint from 2015 to 2018 with Prof. James Durrant at Imperial College London, UK, to fully enter the field of solar energy conversion.
In-Person: ABB 102
Online: Echo360