Profile
| Keywords: | Photocatalytic Energy Conversion, Isolated atom catalysts, Water splitting, Defect Engineering, Semiconductors |
Energy and fuel production through solar light harvesting is one of the viable options to decrease carbon emissions. However, a valuable alternative to fossil fuels requires the development of cost-competitive materials. Semiconductor metal oxides are among the most widely adopted materials for solar energy conversion into chemical energy (H2), produced via photocatalytic water splitting.
Here, we aim to develop low-cost and energy-efficient artificial photosynthesis units to produce H2 from water. The system consists of TiO2 decorated with single-site catalysts, i.e., single-type atoms or a combination of atoms as co-catalyst.
We focus on synthesizing, discovering, and analyzing the effectiveness of newly designed catalysts based on single, bi-, or multi-atom decorated semiconductors intended for photocatalytic H2 evolution. FES Funded ProjectsOutputs
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| Electrocatalytic Generation of H2 From Wastewater Using Pt decorated TiO2 Catalysts Isabella Smith, Ula Suliman, Dr. Shiva MohajerniaT12-Q03 University of Alberta | Activity | 2024-05-09 | | | Mesoporous BiVO4 -based Photoelectrode in Water Splitting PhotoreactorT12-Q03 University of Alberta | Activity | 2024-05-09 | | | Semimetallic Ti-based Bimetallic Oxide: Promising Electrode for Hydrogen GenerationT12-Q03 University of Alberta | Activity | 2024-04-09 | | | Energy Explorers Teacher WorkshopT12-Q03 | Activity | 2024-03-11 | Ula Suliman | | Energy Explorers with Junior High KidsT12-Q03 | Activity | 2023-11-23 | Ula Suliman | | Energy Explorers for Science Literacy Week 2023 - WISESTT12-Q03 | Activity | 2024-05-09 | Ula Suliman | | Enhanced Oxygen Evolution Reaction Performance of ZnO Nanorods on Activated Carbon ClothPeer-reviewed journal article published in Energy & Fuels (Vol. 39, Issue 12, March 2025), reporting the development of a cost-effective, binder-free oxygen evolution reaction (OER) electrocatalyst. The study demonstrates that ZnO nanorods grown on electrochemically activated carbon cloth (ZnO NRs/ECAT@CC) exhibit enhanced OER performance and stability in alkaline conditions, offering a promising alternative to precious-metal-based catalysts for sustainable hydrogen production.
T06-A07 University of Alberta | Publication | 2025-03-18 | | | TeamUP Science - outreach event Paniz, Niyaz, Tooba and Ula volunteered with TeamUP Science at an outreach event held at the University of Alberta on March 9. Paniz and Niyaz assisted Ula in presenting an engaging live demonstration on hydrogen gas production and water splitting to enthusiastic high school students.
Event holder: TeamUp Science
Location: University of Alberta
Date: March 9, 2025
T06-A07 | Activity | 2025-03-09 | Paniz Hajialigol, Niyaz Khan Sujakani, Ula Suliman, "Tooba Mahmood" | | NARGMATs representation - as part of the Future Energy Systems initiative at the Canadian Association of Petroleum Producers (CAPP) mixerUla and Parsa represented NARGMATS as part of the Future Energy Systems initiative at the Canadian Association of Petroleum Producers (CAPP) mixer. Their goal was to introduce green hydrogen energy as a compelling investment opportunity for energy industries. T06-A07 | Activity | 2024-11-03 | Ula Suliman, "Parsa Borhani" | | Climate Quest Exhibit @ TELUS World of ScienceDecember 14, 2024: Ula / Climate Quest Exhibit @ TELUS World of ScienceT06-A07 | Activity | 2024-12-14 | Ula Suliman | | Energy TalksJune 19, 2024: Energy Talks (Dr. Mohajernia, Ula) https://www.youtube.com/watch?v=u_7-d6cSZSc&t=3541sT06-A07 University of Alberta | Activity | 2024-06-19 | | | AWSN x FES: WinSTEM Week at the Thelma Chalifoux SchoolT06-A07 | Activity | 2024-10-10 | Ula Suliman | | Ask an Energy Expert Series T06-A07 | Activity | 2024-09-04 | Ula Suliman | | Exploring the Ultra-Low Loading of IrOx on TiO2 Nanotube Arrays Using a Facile Electrochemical MethodProton exchange membrane (PEM) water electrolyzers are key technologies in aiding the transition towards sustainable future energy systems. Despite their compatibility with other renewable energy sources, including wind and solar energy, the scarcity and the resultant high cost of the state-of-the-art water splitting catalysts such as iridium oxide, and the bottlenecked kinetic performance of the anodic oxygen evolution reaction (OER) limits the widespread use of PEM water electrolyzers. In this work, we present a simple methodology to boost the utilization of iridium oxide catalysts by decreasing the loading of iridium on TiO2 nanotube arrays. Self-assembled titania nanotubes with easily controllable morphology can be conveniently grown via room-temperature anodization, through which we intrinsically embed IrOx into the tube walls.[1] As TiO2 is an n-type semiconductor exhibiting current blockages in anodic electrochemical profiles, defect engineering techniques are used to introduce point defects such as Ti3+ and oxygen vacancies (VO) to enhance the conductive and electrocatalytic properties of the resultant IrOx@TiO2 catalyst.[2] The resultant binder-free electrodes were characterized using methods including X-ray photoelectron spectroscopy, HAADF-STEM, and electrochemical voltammetry tests. Results of this study give a novel perspective on designing low-loading OER catalysts using a simple one-pot strategy.
T06-A07 University of Alberta | Activity | 2025-05-18 | | | Under review manuscript (Journal of Materials Chemistry A) - Ula's workThis study explores the OER and GOR performance of TiO2 nanotubes (TiO2-NTs) decorated with copper (Cu) species.T06-A07 University of Alberta | Publication | 2025-05-04 | | | Future Energy Systems' Energy Explorers program - TELUS World of Science Paniz volunteered with the Future Energy Systems' Energy Explorers program at the University of Alberta. On March 29, she showcased her hydrogen energy and water-splitting demonstration to enthusiastic young learners at TELUS World of Science - Edmonton.
Event holder: Future Energy Systems
Location: TELUS World of Science - Edmonton
Date: March 29, 2025
T06-A07 | Activity | 2025-03-29 | Paniz Hajialigol | | In situ Pt single-atom trapping on TiO2 nanotubes via ultrasonication: a one-pot approach to produce active electrodes for electrocatalytic H2 evolutionT12-Q03, T06-A07 University of Alberta | Publication | 2024-09-01 | "Sina Hejazi ", Sadegh Pourali, "Ali Kosari ", "Nastaran Farahbakhsh ", Manuela S Killian, Mohajernia, S. | | pH-Tuning Strategy for Spontaneous Deposition of Pt Single Atoms on TiO2 NanosheetsIn this work, we demonstrate that Pt SACs can spontaneously deposit on the surface, driven by electrostatic forces; the key is to determine the golden pH and surface potential. We conducted a comprehensive investigation into the influence of the pH of the Pt-containing precursor on the spontaneous adsorption of Pt SACs onto TiO2 nanosheets (TiNSs). We introduced a straightforward pH-dependent and charge-dependent strategy for the solid electrostatic anchoring of Pt SAs on TiNSs. X-ray photoelectron spectroscopy (XPS) and high-angle annular dark-field imaging scanning transmission electron microscopy (HAADF-STEM) were used to evaluate the Pt SA-decorated samples. Photocatalytic hydrogen production activity was assessed under UV (λ = 365 nm) irradiation. Notably, we found that at a pH of 8, slightly below the measured point of zero charge (PZC), a unique mixture of Pt clusters and SAs was deposited on the surface of TiNSs. This unique composition significantly improved hydrogen production, resulting in approximately 3.7 ml of hydrogen generated after 8 hours of UV exposure by only 10 mg of the Pt-decorated TiNSs (with Pt loadings of 0.12 at%), which is about 300 times higher than the undecorated TiNSs.T12-Q03 | Activity | 2025-05-18 | Sadegh Pourali, "Kenza Toukabri", "Sina Hejazi", Manuela S Killian | | Defect-Engineered TiO2 Supports for Pt Single-Atom Catalysts: Insights into HER from DFT CalculationsDespite experimental progress in this field, a comprehensive understanding of the relationship between surface defects and SACs stabilization remains elusive, particularly from a Density Functional Theory (DFT) perspective [4]. In this study, first-principles DFT calculations, including energy band structures, density of states (DOS and PDOS), charge density distributions, and Gibbs free energy diagrams for the hydrogen evolution reaction (HER), are performed on both pristine and defect-engineered TiO2 surfaces hosting Pt single atoms (SAs) and clusters. The results reveal that oxygen vacancies play a critical role in optimizing the free energies of intermediates during the HER process on Pt SAs@TiO2. These defects effectively modulate the adsorption and desorption behavior of reaction intermediates, ultimately accelerating the catalytic kinetics. This work bridges the knowledge gap by offering detailed atomic-scale insights into the interplay between surface defects and SAC stabilization, paving the way for the rational design of efficient catalysts for hydrogen production.T12-Q03 University of Alberta | Activity | 2025-05-18 | | | Defect-Engineered TiO2 Nanosheets Decorated with Rhenium Co-Catalysts: A Promising Photocatalyst for Hydrogen ProductionIn this work, we investigated the effect of Re species, derived from ammonium perrhenate (NH4ReO4), on the photocatalytic hydrogen production performance of TiO2 nanosheets (TiNSs). Simultaneously, oxygen vacancies were introduced into the TiNSs through thermal annealing in an Ar/H2 atmosphere to modify their electronic properties. Oxygen vacancies improve the band gap and charge carrier dynamics, which are critical for photocatalytic applications [4]. The Re species were chemically decorated on the TiNSs support to explore potential synergies between defect-engineered TiO2 and rhenium-based co-catalysts. The experimental procedure involved annealing TiNSs at various flow rates and exposure times to create varying levels of oxygen vacancies. The annealed TiNSs were dispersed in a 1 mM Re precursor solution, stirred, centrifuged, and dried. The Re@TiO2 TiNSs were then characterized through X-ray diffraction (XRD), filed-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Moreover, their photocatalytic hydrogen evolution performance was evaluated under UV illumination (λ = 365 nm) at 1, 3, 8, and 22 hours. Our results revealed a significant improvement in the photocatalytic hydrogen production when Re species were incorporated into the TiNSs annealed for 1 hour under a flow rate of 50 mL/min, where the highest hydrogen production of ~45000 ppm was observed after 22 hours of illumination, which is more than 50 times higher than that of the pristine samples. This enhancement can be attributed to the synergy between the oxygen vacancies in TiNSs and the Re species, which acted as efficient electron sinks to suppress charge recombination and facilitate hydrogen evolution. However, prolonged annealing at 2 and 4 hours decreased performance, likely due to excessive defect formation or agglomeration of Re species. In conclusion, this study demonstrates the potential of rhenium-based co-catalysts in combination with defect-engineered TiNSs for photocatalytic hydrogen production for the first time. This work opens new avenues for utilizing Re-based materials as effective co-catalysts for TiO2 and other semiconductor systems in sustainable hydrogen production applications.T12-Q03 University of Alberta | Activity | 2025-05-18 | | | NRGMATs Energy Materials Group – Lab Tour Summary for Edmonton's Teachers
In this 25-minute session, participating teachers were introduced to the research activities of the NRGMATs Energy Materials Group, led by Sadegh. The tour focused on the group’s work in developing advanced materials for clean energy technologies, such as photocatalytic hydrogen production and nanostructured semiconductors.
Teachers explored how these research themes connect to high school science curricula—particularly topics like energy conversion, chemical reactions, material properties, and nanoscience. Through live demonstrations and hands-on explanations, the tour highlighted practical ways these concepts could be brought into the classroom to inspire students and show the relevance of science to real-world challenges.
The session provided valuable opportunities for dialogue between researchers and educators, helping bridge the gap between cutting-edge science and classroom teaching.
T12-Q03, T06-A07 | Activity | 2024-08-14 | Sadegh Pourali | | Nanostructured Nickel Oxide Electrodes Fabricated Using Glancing Angle Deposition for Electrochemical Water SplittingIn this study, the effects of deposition angle, film thickness, and deposition rate over the oxygen evolution reaction (OER) performance of nickel oxide GLAD-fabricated electrodes were investigated. Thicknesses of 300 nm, 500 nm, 700 nm, and 1000 nm were considered, while deposition angles of 74°, 78°, 83°, and 86° were tested. Among these parameters, the best performance was achieved at a deposition angle of 78° and a thickness of 500 nm, where an optimal balance of surface area and mass transfer was achieved, resulting in an overpotential of 355 mV at 10 mA/cm². It was observed that increasing the deposition angle caused a decrease in areal density of the nanocolumnar NiO structures. To further optimize electrode performance, the effect of deposition rate was examined under four different scenarios, all tested at a deposition angle of 78° and a thickness of 500 nm: (1) a constant deposition rate of 0.2 nm/s, (2) a constant deposition rate of 0.4 nm/s, (3) a deposition rate starting at 0.2 nm/s and gradually increasing to 0.4 nm/s, and (4) a deposition rate starting at 0.4 nm/s and gradually decreasing to 0.2 nm/s. The results revealed that the fourth scenario, where the deposition rate started at 0.4 nm/s and decreased to 0.2 nm/s, yielded the best performance. Under these conditions, an overpotential of 300 mV was achieved at 10 mA/cm². X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the crystal structure and morphology of the electrodes. These findings highlight the critical role of fine-tuning deposition parameters in optimizing electrode performance and advancing cost-effective green hydrogen production.T06-A07 University of Alberta | Activity | 2025-05-18 | | | Minimal Size, Maximum Impact: The Role of Single-Atom Pt in Photocatalytic Hydrogen Production on TiO₂In this presentation, we investigate the use of Pt atoms that are dispersed and anchored as single atoms on nanocrystals, powders, and nanotubes of TiO₂ as cocatalysts for photocatalytic H₂ production. We overview several strategies concerning the trapping and stabilization of SAs on photocatalysts and present some findings related to SA-Pt photocatalysts with superior photocatalytic activity compared to traditional configurations of co-catalysts on semiconductor substrates. Moreover, we demonstrate that only a limited fraction of the overall Pt deposited, when stably trapped as single atoms, supplies nearly all the photocatalytic activity observed for Pt-decorated catalysts.T12-Q03 University of Alberta | Activity | 2025-05-18 | | | Optimizing the Ultra-High Dispersion of Ir on NiO Nanosponge for Enhanced Oxygen Evolution ReactionIn this study, we employ a two-step electrochemical anodization process to fabricate highly porous nickel oxide nanosponges [3]. We then introduce an innovative sonochemical technique that creates defects and achieves ultra-high dispersion of Ir on these porous NiO nanostructures by varying the Ir solution concentration. This single-step sonication process generates a high density of defects within the NiO matrix, stabilizing dispersed Ir sites across the nanostructure [4]. By combining electrochemical anodization with defect engineering via sonication, we achieve efficient entrapment and uniform distribution of Ir at the atomic level. Our results show that defects and the ultra-high dispersion of Ir atoms significantly enhance OER electrocatalytic efficiency. Incorporating Ir into the NiO nanosponge support maximizes the active sites, improving H2O molecule adsorption and its conversion to OH, resulting in more efficient catalysts with improved reaction kinetics for OER. The electrodes are characterized using advanced microscopy techniques, including FESEM, TEM, and HAADF-STEM, alongside spectroscopy methods such as XPS and ToF-SIMS [5]. Linear sweep voltammetry is used to assess the O2 evolution activity of NiO electrodes. These results highlight a significant improvement in the electrocatalytic efficiency of nanostructured NiO electrodes modified with durable and optimized Ir co-catalysts via the sonochemical technique.T12-Q03 University of Alberta | Activity | 2025-05-18 | "Nastaran Farahbakhsh ", "Majid Shahsanaei ", Mohajernia, S., "Sina Hejazi ", Manuela S Killian |
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