Catalysis

New ‘Molecular Dam’ Stops Energy Leaks in Nanocrystals

Daniel Morton — Tue, 21 Oct 2025 19:17:19 +0000

New ‘Molecular Dam’ Stops Energy Leaks in Nanocrystals Daniel Morton Tue, 10/21/2025 - 13:17

Daniel Morton

A molecular engineering breakthrough could make key light-driven reactions over 40 times more efficient.

A collaborative team of scientists from the ��, the University of California Irvine, and Fort Lewis College, led by RASEI Fellow Gordana Dukovic, has found a way to slow energy leaks that have impeded the use of tiny nanocrystals in light-driven chemical and energy applications. As described in a new article published in the journal Chem, the team has used a molecule that strongly binds to the nanocrystal’s surface, essentially acting like a ‘dam’ to hold back the energy stored in the charge-separated state formed after light absorption. This technique extends the lifetime of the charge separation to the longest recorded for these materials, providing a pathway to improved efficiencies and more opportunities to put this energy to work in chemical reactions. This collaboration is part of the U.S. Department of Energy funded Energy Frontier Research Center: Ensembles of Photosynthetic Nanoreactors (EPN).

Harnessing Light to Power Chemistry

Many of the products we rely on today, from plastics, to fertilizers, and pharmaceuticals, are created, or synthesized, through industrial chemical reactions that can often require immense heat and pressure, typically generated by burning fossil fuels. For decades there has been research exploring a less harsh and theoretically more efficient alternative: Photocatalysis. The goal is to use a compound, a “photocatalyst”, that can harness the energy in light and use it to power chemical reactions at room temperature. Semiconductor nanocrystals, particles that are over a thousand times smaller than the width of a human hair, are a leading candidate for this job. When exposed to light these nanocrystals generate a short-lived spark of energy, in the form of a separated negative charge (an electron) and a positive charge (called a “hole”, due to the absence of an electron). A key challenge in this area is that this spark disappears quickly, because the electron and the hole recombine, and the energy is lost before it can be put to good use.

Building a Molecular Dam

To solve this problem the team focused on building what we might call a ‘molecular dam’, something that helps prevent, or at least slow down, the electron and the hole from recombining. This research started with cadmium sulfide (CdS) nanocrystals and designed a molecule (in this case a phenothiazine derivative) with two key features; first the incorporation of a chemical group that acts as a ‘sticky anchor’ (in this case a carboxylate group), which binds strongly to the nanocrystal surface, and second, a molecular structure that quickly accepts the positive charge (the hole), from the nanocrystal to realize the light-driven charge separation event.

By anchoring this molecule to the surface of the nanocrystal the team created a highly efficient and stable pathway. As soon as exposure to light creates the electron-hole pair in the nanocrystal, the anchored molecule shuttles the hole away, physically separating it from the electron. This physical separation of the electron and the hole prevents the two from quickly snapping back together and wasting the energy. This results in a charge-separated state that lasts for microseconds, which is an eternity in the world of photochemistry, creating a much larger window of time for future researchers to work with in terms of harnessing this captured light-driven energy for useful chemical reactions. The team was able to prove the significance of the ‘sticky anchor’ carboxylate, by comparing their derivative to a phenothiazine that lacked the anchor, which was shown to be far less effective at holding the energy, demonstrating that this anchoring to the surface was key to this system’s performance.

This collaborative work was done as part of the U.S. Department of Energy funded Energy Frontier Research Center (EFRC) Ensembles of Photosynthetic Nanoreactors (EPN). EPN consists of 17 senior investigates located across 9 universities and 3 U.S. national laboratories. The goal of EPN is to provide a forum for collaboration, bringing together expertise to advance the frontiers of discovery and fundamental knowledge in photochemical energy conversion. The aim is to not only foster new discoveries and applications, but in doing so, train the researchers who will build knowledge and advances that will benefit the United States innovation and economy.

This project took advantage of the different areas of expertise of each team to generate ideas and quickly execute them. Kenny Miller’s group of dedicated undergraduate researchers at Fort Lewis College synthesized the carboxylated phenothiazine derivative (and a slew of others). Miller then sent the derivative to Jenny Yang’s group of inorganic electrochemists at UC Irvine for advanced electrochemical characterization. Gordana Dukovic’s group here at �� synthesized the nanocrystals, tested their compatibility with the derivative, characterized the binding, and undertook the advanced laser spectroscopy study to see how the electrons and holes behaved.

“The first time I saw the results-saw how effective our ‘molecular dam’ was at slowing charge recombination-I knew we had struck gold” explained Dr. Sophia Click, a lead author on the study. “To slow charge recombination from nanoseconds to microseconds, and with a molecule that can be paired with so many existing photocatalyst systems, makes this work vital to share with as many researchers as possible.”

Development of this ‘molecular dam’ could have implications for the future design of catalysts for light-driven chemistry. By increasing the efficiency of the initial energy-capture step, this system improves the efficiency of the entire process. This could improve not just one specific reaction, but rather, benefit a broad range of light-driven chemical reactions. A key technology this could enhance is the development of light-driven creation of chemical commodities or high-value chemicals. This research provides a more robust and versatile chemical toolkit for exploring these possibilities.

This discovery in controlling charge-separation, and energy, at the nanoscale is an important design parameter into developing light-driven chemistry, and hopefully light-driven chemical manufacturing. Imagine a future where materials, such as plastics, and even pharmaceuticals, are not made in energy inefficient high-temperature reactors powered by fossil fuels but instead are synthesized directly and efficiently using the power of light. While this vision is still on the horizon, the work done in this collaboration provides an important piece of the scientific puzzle, constituting a huge leap toward one day achieving these goals.

The study, “Exceptionally Long-Lived Charge Separated States in CdS Nanocrystals with a Covalently Bound Phenothiazine Derivative” was published in the journal Chem. This work was supported by the U.S. Department of Energy, Office of Science, as part of the Energy Frontier Research Center: Ensembles of Photosynthetic Nanoreactors (EPN; DE-SC0023431), with additional experiments on nanorods supported by Air Force Office of Scientific Research under AFOSR (FA9550-22-1-0347).

October 2025

Off

Traditional

White

RASEI Led team select to compete in the 2025 Lab Venture Challenge

Daniel Morton — Fri, 26 Sep 2025 16:02:11 +0000

RASEI Led team select to compete in the 2025 Lab Venture Challenge Daniel Morton Fri, 09/26/2025 - 10:02

September 2025

Off

Traditional

White

Building Energizing Connections: Front Range Researchers Unite

Daniel Morton — Wed, 10 Sep 2025 16:33:38 +0000

Building Energizing Connections: Front Range Researchers Unite Daniel Morton Wed, 09/10/2025 - 10:33

Daniel Morton

This August (18-19, 2025), the Front Range came alive with scientific collaboration as the 2025 Front Range Electrochemistry Workshop (FREW) brought together over 100 researchers from across the region. Hosted at ��'s Sustainability, Energy, and Environment Community (SEEC) building, this two-day gathering showcased the power of regional partnership in tackling some of our most pressing energy challenges. The workshop was funded by NSF’s Institute for Data Driven Dynamical Design.

Find out more about the workshop

Front Range Electrochemistry Workshop

ChBE Highlight

What is Electrochemistry and Why Does It Matter?

Electrochemistry might sound complex, but it's essentially the science of using electricity to drive chemical reactions—and it's at the heart of our clean energy future. Think of the battery in your phone or car, the fuel cells powering some buses, or emerging technologies that can capture carbon dioxide from the air and turn it into useful materials. All of these rely on electrochemical processes that researchers are working to improve and expand.

Regional Collaboration

The Front Range is developing as a hub for this critical research. This workshop exemplified that spirit, bringing together researchers from Colorado School of Mines, ��, Colorado State University, the University of Wyoming, and several National Laboratories to share ideas, forge new partnerships, and identify opportunities for joint research.

"It was a really great meeting, with participants bringing an excited and motivated attitude that made for a really fantastic atmosphere," noted RASEI Fellow Mike Toney, who served on the organizing committee. The participants generated a great atmosphere at the workshop as researchers moved between presentations, interactive poster sessions, and innovative "collaboration pitch" sessions designed specifically to spark new partnerships, especially among graduate students. “The poster session was a great experience. I really enjoyed sharing my sodium-ion battery research and was exposed to a lot of fresh ideas across the electrochemistry space from other students and speakers” explained Loren Andrews, a Graduate Student at ��.

Tackling Real-World Challenges Together

The workshop covered a diverse range of applications that could transform how we store and use energy:

Advanced Battery Technologies: Improving today's lithium-ion batteries and developing next-generation alternatives, including solid-state batteries that could be safer and more efficient
Grid-Scale Energy Storage: Exploring redox flow batteries that could store renewable energy for entire communities
Clean Transportation: Advancing fuel cell technology for cars, trucks, and other applications
Sustainable Chemical Manufacturing: Developing electrochemical processes to catalyze chemical transformations
AI-Powered Discovery: Using machine learning to accelerate the development of new materials and processes

Using Interactive Approaches to Develop Connections

What made this workshop particularly engaging was the opportunity to connect across different institutes along the Front Range region. The interactive format encouraged researchers to step out of their individual labs and think collectively about connected strengths and opportunities. Rather than just have lecture style presentations, the organizers developed a mixed schedule. The poster sessions weren't just about presenting results, they were also networking opportunities. The pitch sessions weren't just about sharing ideas, they were also about identifying concrete ways to work together.

To incentivize participation and develop some friendly competition in th poster and collaborative pitch sessions the organizers were able to offer a prize structure. For the poster session Abby Cardoza (Colorado School of Mines) won first place and Loren Andrews & Peter Romero (��) won second place. For the Pitches a team with Cindy Wong (��), Colby Evans (NIST), Emily Hansen (Colorado School of Mines), and Olajide Aijbade (University of Wyoming) took first place, and second place went to a team including Rebecca Beswick (��), Peter Romero (��), Bryce Rives (��) Chris Sedmak (Colorado School of Mines), Matt Hammel (Colorado School of Mines). Congratulations to everyone!

Daniel Morton — Mon, 07 Jul 2025 16:34:22 +0000

Finding the On switch for more efficient light-driven chemistry Daniel Morton Mon, 07/07/2025 - 10:34

Daniel Morton

Find out more

Read the Article

Collaboration led by RASEI members Obadiah Reid and Garry Rumbles solves a long-standing puzzle in important organic chemical transformation.

In the world of organic chemistry, making new molecules, the building blocks for everything from advanced electronic materials to pharmaceuticals, is a bit like being a chef. Chemists are always looking to improve the recipe, to make it faster, cheaper, more efficient, and produce less waste. In recent years one of the most exciting new ‘cooking techniques’ is nickel photocatalysis, which uses abundant, low-cost nickel and the power of light to enable chemists to build complex molecules under mild conditions.

This technique has emerged as something of a game-changer in building molecules, but it comes with a significant puzzle. The nickel catalyst, as it is normally added to a reaction, is in a dormant state (called a ‘pre-catalyst’). To get the reaction moving, the catalyst needs to be ‘woken up’. For years, scientists were not sure what the wake-up call was. The activation from pre-catalyst to the functioning catalyst was something of a black box, with numerous theories for what was happening. This led to the assumption that each reaction was unique, and each reaction required its own individual and complicated startup sequence. This has often required a lot of work to find the right ‘On switch’.

This collaborative study, led by RASEI researchers Obadiah Reid and Garry Rumbles at the National Renewable Energy Laboratory (NREL), brings together expertise from the SLAC National Accelerator Laboratory, Brookhaven National Laboratory, Argonne National Laboratory and Northeastern University. Together, the scientists have identified key features of the transformation from pre-catalyst to active catalyst. In the report, just published in Nature Communications, the team shows that there is a universal ‘On switch’ to start these powerful reactions, and the key to this transformation is light.

Imagine a high-tech machine delivered in a locked crate. You know that once you get it out and get it running, it can do amazing things, but you don’t have the key. For years, chemists were essentially trying to pick the lock in different ways every time they wanted to use it. This study describes a universal key for getting the crate open.

It was found that light, either directly, or transferred from another light-absorbing molecule, provide a jolt of energy that breaks a bond in the nickel pre-catalyst structure. This process, which is called photolysis, activates the nickel complex, getting it ready to do the chemistry. This initial step is something that has previously been proposed but never fully proven.

The team brought together a sophisticated array of tools to effectively investigate this mechanism, including incredibly fast laser systems that can watch chemical changes happen in fractions of a second. This allowed them to witness the ‘unlocking’ process in real-time and identify the exact sequence of events. They observed that after the initial light-induced bond breaking, the catalyst can then interact with molecules in the surrounding solvent, forming a temporary ‘reservoir’ that holds the catalyst in a state ready for the main reaction.

Building this body of evidence and developing these findings required a significant team effort, bringing together scientists from across the country, from multiple national labs and universities. RASEI Scientists at �� and NREL used advanced spectroscopy to track the catalyst’s behavior, while researchers at SLAC used high-powered X-rays to confirm changes in the structure of the nickel complex. This combination of knowledge and experience with cutting-edge instrumentation was essential in providing a complete understanding of these reactions begin.

Development of a unified explanation for how one of the most important tools in an organic chemist’s toolbox is initiated has important implications. Understanding this fundamental activation step allows chemists to move from guessing to designing. Not only does this support improvement in the activation of existing reactions, it also provides opportunities to design new transformations, all of which will streamline the manufacture of chemical commodities, such as pharmaceuticals and materials.

JULY 2025

Off

Traditional

White

Photolytic activation of Ni(II)X2L explains how Ni-mediated cross coupling begins

Daniel Morton — Tue, 01 Jul 2025 17:11:39 +0000

Photolytic activation of Ni(II)X2L explains how Ni-mediated cross coupling begins Daniel Morton Tue, 07/01/2025 - 11:11

NATURE COMMUNICATIONS, 2025, 16, 5530

Off

Traditional

White