© April 2023. Tanja Wagensohn UR. All rights reserved.
Harnessing light energy by employing a colored dye like chlorophyll and using that to synthesize high-value molecules: A trending research field over the last 10 years which “has been heavily influenced by chemistry at Regensburg,” says Joshua Barham, PhD, synthetic-organic chemist, Sofja Kovalevskaja-Award Winner 2019. Recently, Joshua has been awarded an ERC starting grant for an innovative research project in the field of synthetic photo-electro-chemistry called ‘HELIOS’. The objective is to harness the synergy of light-driven and electrified chemistry to streamline the synthesis of active pharmaceutical ingredients by utilizing biomass feedstocks and recycling persistent pollutants.
Natural visible light consists of particles called photons – each one a miniature packet of limited energy. A single photon alone is insufficient to engage stable molecules like carbon dioxide and water in photosynthesis. Nature’s elegant solution is to harvest and compile multiple photon energies by using chlorophyll - a visible light-active ‘photocatalyst’ in a complex photosystem. The last decade has witnessed great success in using artificial ‘photocatalysts’ to drive molecular chemical reactions using single photons at a time. However, researchers struggled to replicate the concept of harvesting multiple photons, constraining the technology to rather ‘activated’ chemical feedstocks.
Joshua and his colleagues want to approach the challenge in a different way by leveraging catalysts which harvest both electrical energy and photon energy inputs, using electricity as a user-tunable base layer of energy that can be ‘topped up’ with photons.
Developing European Technology
Within the next five years, Joshua Barham seeks to establish photo-electro-chemistry in Europe as a promising technology for organic synthesis. He and his team are one of the few research groups in Europe working in this field. “There has been ample development in this technology for energy applications, for example in splitting water into hydrogen and oxygen, but limited attention on using this for organic synthesis targeting high value molecules.” Additionally, the young chemist would like to decentralize this technology in Europe.
Working for five years in chemical industry during his PhD and postdoc opened his eyes to the real-world context of organic chemistry, Joshua says, but also taught him that he valued the flexibility to pursue his own ideas: “I love research.” His eyes sparkle as he thinks aloud about what to discover next: “I would be interested very much in using DNA encoded libraries for discovering new catalytic reactions. I think this would be an incredibly powerful and rapid way to discover the chemistry of the future.”
The Bear Clan and the Vulf Peck
As a postdoc in Japan, involved in a very specific research project and dealing with the nitty-gritty details of the raw data, it was challenging to “suddenly transition to a position where you are in charge of several researchers and not have as detailed a level of insight on each individual project”, Joshua explains. “On the other hand, the broader overview of chemistry, the ability to make connections between projects and seeing students develop their own ideas are elements that really excite me.” His “Bear Clan” is a team of 10 diverse researchers – from Germany, China, India, Poland, the Philippines, Tajikistan, and Italy.
“The key for a diverse, international team to flourish is to treat everyone with respect, patience, and equal opportunities”, says Joshua, who enjoys writing research papers while listening to music. “Right now I really dig Vulfpeck. It’s so funky and it’s low volume”. Among other genres, he also regularly listens to progressive house. “I like something that has a beat and that builds in momentum. It gives me focus.”
Regensburg has not only been a place of research for Joshua. Regular hiking in the Bavarian forest/Alps replaced climbing Japan’s Mount Fuji three times (“..twice was enough. Next stop Zugspitze!”), and eating sauerkraut fills the gap left by kimchi and umeboushi (“I do love fermented food…”). While he misses seeing out the winter with a pint of ale in a cosy British pub, “nothing beats a Weißbier” to quench the thirst in the summer heat of Bavaria’s boisterous beer gardens.
Joshua Barham is a sociable person who likes to think and discuss, not only about research, but also about the challenges and opportunities for early career scientists. “Undoubtedly, social media is a powerful tool for science communication - but how can we scientists best adapt to this increasingly rapid way of communicating research and research achievements?” Joshua expresses concern about its risks, seeing a tendency for algorithms to narrow the exposure to different research fields and put additional pressures on young researchers. Another area of concern is the use of AI tools – Joshua is convinced that ethical standards must be tightened in order to protect the independency and impact of science.
As a high-schooler, Joshua was more interested in biology and physics than chemistry. The penny dropped while he was left stranded in the US by the eruption of an Icelandic volcano, revising for his first year undergraduate chemistry exams at the airport. 12 years later, Joshua is striving to attain a professorship before the end of his ERC grant. Before that, he will enjoy a bit of paternity leave with his family – as a first time father!