As we came to the end date of the MOF2H2 project, we would like to present you several reflections from members of our consortium. These articles provide insights into project’s path, progress, and its outcomes. The participants describe the scientific ambitions that drove MOF2H2, and how these ambitions successfully translated into concrete results.
As our second contributor, we are happy to share with you an account from our partner from the Technion, Israel Institute of Technology (TECH).
Scientific ambition: What made MOF2H2 worth pursuing
MOF2H2 project was interesting for Technion from the beginning because it has the ambition to develop a system that has much higher level of efficiency compared to other photocatalytic systems. They were keen to work on a fully noble-metal-free system for overall water splitting using metal–organic frameworks (MOF), while targeting a 5% solar-to-hydrogen efficiency.
Scientifically, the most compelling aspect was the integration of materials design, mechanistic spectroscopy, and device-level validation within a single framework. Rather than focusing only on incremental activity improvements, MOF2H2 aims to understand and control charge separation, metal–ligand coordination dynamics, and trap-state engineering to enable stable and efficient hydrogen production.
From a technological point of view, they were curious to commit to advancing from material discovery to TRL4 lab-scale demonstrators, combined with sustainability and techno-economic assessment. These steps reflected a clear pathway toward practical implementation. The combination of fundamental mechanistic science and application-oriented development made the project particularly ambitious, and thanks to this aspiration, it has proved impactful overtime.
Technion’s contribution: Roles, results, and concrete outputs
Technion – Israel Institute of Technology was mainly responsible for WP3.1, which was later adapted and continued as modified WP3, task 3.3. They were equally responsible for WP3.2, which evolved into modified WP3, task 3.4. Their core role across these work packages was the advanced spectroscopic and mechanistic characterisation of the synthesised MOFs and MOF–co-catalyst heterostructures.
In WP3, T3.3, TECH focused on elucidating the electronic structure, charge separation pathways, trap-state formation, and excited-state dynamics of optimised MOF systems using UV–Vis DRS, steady-state and time-resolved photoluminescence (PL/TRPL), and nanosecond transient IR (TRIR) spectroscopy.
Within WP3.4, Technion investigated the interfacial charge-transfer processes in MOF–co-catalyst heterostructures, assessing how metal nanoparticle co-deposition, metal/ligand substitution, and structural modification influence photocatalytic overall water splitting performance.
To be more concrete, they contributed primarily to the mechanistic validation and structure–activity correlation of the optimised MOF ZrCuPyC photocatalysts and MOF–co-catalyst heterostructures within WP3. The main results and deliverables include:
- Comprehensive advanced spectroscopic datasets (UV–Vis DRS, steady-state FTIR, PL, TRPL, and nanosecond TRIR) for first-generation and refined MOF ZrCuPyC systems, including metal-substituted and Cu-modified Ti-based frameworks.
- Identification of trap-state/miniband formation in Zr- and Cu-modified MOFs, and demonstration of their role in stabilising charge carriers and improving photocatalytic hydrogen evolution performance.
- Time-resolved kinetic analysis of charge relaxation pathways, establishing how metal incorporation modifies excited-state lifetimes and internal electric-field-driven coordination dynamics.
- Direct observation of photoinduced metal–ligand coordination switching (bidentate ↔ monodentate) in Ti-based MOFs, revealing how charge separation influences structural dynamics relevant to overall water splitting.
- Mechanistic clarification of MOF–co-catalyst interfacial charge transfer, showing how Cu loading alters electron migration pathways, suppresses or stabilises transient distortions, and impacts catalytic efficiency.
- Design guidelines for MOF optimisation, demonstrating that improved hydrogen production is governed by controlled charge migration and trap-state engineering rather than extended radiative lifetimes alone.
Lessons learned: Challenges, growth, and organisational impact
The main challenges encountered by Technion were of scientific and methodological order. Primarily, they were related to extracting reliable mechanistic information from highly dynamic MOF systems and linking spectroscopy to catalytic performance. Nevertheless, TECH have always found a solution on how to surmount these issues, and they could move forward at all times.
The scientist had to figure out weak and complex transient signals – so certain moments where MOFs exhibit broad, overlapping vibrational features in TRIR measurements, which made the band assignment difficult. This was addressed through systematic comparison with steady-state FTIR, excitation-wavelength-dependent experiments, and careful Δν (carboxylate splitting) analysis to track coordination changes.
Regarding the problematic of distinguishing electron- vs hole-driven processes, TECH has encountered some difficulties analysing charge-transfer pathways, which were not directly evident from raw transient spectra. They resolved this issue by conducting controlled experiments with electron and hole scavengers, allowing selective identification of charge-carrier contributions to the observed spectral changes.
Moreover, samples’ variability, differences in solvent history, defect density, and Cu loading affected spectral intensity and kinetics. The issue was overcome by maintaining identical measurement protocols, normalising data carefully, and comparing trends across multiple structurally related samples.
Finally, photoluminescence lifetimes alone did not correlate directly with hydrogen evolution rates. Therefore, TECH developed a mechanistic framework focusing on trap-state engineering, coordination switching dynamics, and interfacial charge migration that proved to be more relevant descriptors of photocatalytic efficiency.
Participation in MOF2H2 significantly strengthened Technion’s expertise in advanced time-resolved spectroscopy and mechanism-driven MOF photocatalysis. They were able to enhance their capability to correlate charge-transfer dynamics, trap-state formation, and coordination changes with hydrogen evolution performance. The project expanded Technion’s international research network as well through close collaboration with leading European partners and positioned Technion strongly for future Horizon Europe and solar-fuels-related proposals.
Overall, MOF2H2 reinforced TECH’s role as a key partner for in-depth mechanistic characterisation and structure–activity validation in multidisciplinary hydrogen research projects.
What comes next for Techion: building on MOF2H2’s legacy
MOF2H2’s key contribution to the field of low-carbon hydrogen is demonstrating that metal–organic frameworks can be engineered into efficient, stable, noble-metal-free photocatalysts for overall water splitting, while advancing toward practical implementation.
The project not only validated that MOFs such as MIP-818 possess suitable band-edge positions for HER and OWS but also showed that post-synthetic co-catalyst integration (e.g., Cr₂O₃ nanoparticles) can enhance activity by more than 40%, reduce metal leaching by over 70%, and improve charge-transfer kinetics. The correlation between photocatalytic activity, transient photocurrent response, and reduced charge-transfer resistance establishes clear structure–property–performance relationships.
Importantly, MOF2H2 goes beyond material discovery by combining mechanistic understanding, device-level validation, recyclability testing, isotopic confirmation of water oxidation, and techno-economic assessment. This integrated approach moves MOF-based photocatalysis closer to scalable, sustainable hydrogen production and provides design principles for future low-carbon hydrogen technologies.
Building on MOF2H2’s outcomes, Technion plan to further advance the trap-state engineering, metal–ligand coordination control, and noble-metal-free co-catalyst integration to improve overall water splitting efficiency. Their future work will focus on designing hybrid MOF heterostructures with enhanced charge separation, optimising oxide and 2D co-catalysts for improved interfacial charge transfer and engineering greater structural stability with reduced metal leaching. The aim will also be to integrate MOF materials into photoelectrochemical and scalable reactor platforms. These directions will be pursued through follow-up collaborations, including Horizon Europe and related international funding programmes, to further develop MOF-based low-carbon hydrogen technologies.
“Participation in MOF2H2 significantly strengthened our expertise in advanced time-resolved spectroscopy and mechanism-driven MOF photocatalysis. We were able to enhance tour capability to correlate charge-transfer dynamics, trap-state formation, and coordination changes with hydrogen evolution performance.”
MOF2H2’s potential in the future scientific research
Given that MOF2H2 has already delivered a developed, installed, and demonstrated photocatalytic batch glass reactor (TRL4), the next step should be to optimise and scale the demonstrated technology toward longer-term, higher-throughput operation. This should focus on improving photon utilisation and mass transfer within the existing reactor, enhancing catalyst stability (including leaching suppression), and validating performance under extended continuous illumination cycles. In parallel, upgrading the current batch setup toward semi-continuous/continuous operation with improved catalyst immobilisation and gas separation would be the most direct pathway to higher TRL and closer-to-application low-carbon hydrogen production.
TECH hope MOF2H2 will establish MOF-based photocatalysis as a credible and scalable pathway for low-carbon hydrogen production, shifting the field from exploratory materials research toward application-oriented development. Beyond the project, its impact should lie in providing validated design principles for noble-metal-free overall water splitting, demonstrating that performance, stability, and reactor integration can be addressed simultaneously. The combination of mechanistic understanding, lab-scale demonstrator validation, and sustainability assessment sets a framework that future hydrogen projects can adopt.
More broadly, MOF2H2 can strengthen Europe’s position in advanced materials for solar fuels and contribute to accelerating the transition toward renewable, decentralised hydrogen technologies.
Key recommendation and advice to organisations wishing to build up on MOF2H2
Organisations building on MOF2H2 should adopt a mechanism-driven strategy, focusing on charge separation dynamics, trap-state engineering, and metal–ligand coordination effects rather than activity screening alone.
Advanced time-resolved spectroscopy should be integrated with catalytic testing to establish clear structure–activity relationships. Emphasis should also be placed on co-catalyst optimisation, stability improvement, and leaching suppression.
Finally, early consideration of scalability, device integration, and techno-economic assessment is essential for translating MOF-based photocatalysts into viable low-carbon hydrogen technologies.
