PhD Scholarship in Chemistry NOW AVAILABLE!

Title: Development of photosynthetic protocellsfor low-cost production of solar fuels
Supervisor: Pierangelo Gobbo
Institution: Department of Chemical and Pharmaceutical Sciences, University of Trieste (Italy)
Industry involved: Enphos S.R.L.

The increase in global energy demand and the climate change crisis is causing a progressive increase in global warming and deoxygenation of our atmosphere.[1] Therefore, it is of paramount importance to develop new technologies to simultaneously (i) reduce the global amount of CO2 in our atmosphere, (ii) produce eco-sustainable fuels, and (iii) reoxygenate our planet.
In the past decade, micro-compartmentalized systems called “protocells” have been developed to study complex biological phenomena such as enzymatic metabolism, chemical signalling or photosynthesis under simple and controllable experimental conditions.[2,3] Recently, Dr. Gobbo, in collaboration with the University of Bristol (UK) and the University of Padua (Italy), has synthesized catalytic protocells capable of decomposing H2O2 into oxygen and water starting from poly(diallyldimethylammonium chloride) (PDDA) and a mixture of polyoxometalates: sodium phosphotungstate (PTA) and a synthetic catalyst called “Ru4POM”.[4] The research team has then demonstrated that the same catalytic protocells are capable of utilizing sunlight to oxidize water to protons and O2 (Figure 1) when dispersed in a solution containing Ru(bpy)3Cl2 (a photosensitizer) and Na2S2O8 (a sacrificial electron acceptor).

Figure 1: a) Schematic representation of a catalytic protocell and its photo-reactivity. b) Darkfield microscopy image of a population of protocells structured like described in (a). c) Graph showing the time-dependent production of O2 for: a sample of photocatalytic protocells (dark blue plot); a sample of photocatalytic protocells that have been utilized a second time (light blue plot); control experiments carried out in the absence of light (black plot) or in the absence of the Ru4POM catalyst (orange plot). Non-published preliminary results.

The project starts from these important preliminary results and aims to develop the first photosynthetic protocells capable of utilizing sunlight, water and CO2 to autonomously and continuously synthesize O2 and fuels at low costs. The student will develop these preliminary results into groundbreaking research following their interests and attitudes. Specifically, the student will explore the following possibilities:
1) Test different POM catalysts to lower the production costs of the protocells while maintaining high photocatalytic efficiency.
2) Substitute the Ru4POM/Ru(bpy)3Cl2/Na2S2O8 system with groundbreaking and more efficient antenna systems such as the “quantasome complex” of Ru4POM and perylene bisimide recently reported in Nature Chemistry.[5]
3) Develop protocells with phototactic abilities (autonomous movement towards or away from a light source) to improve their photosynthetic efficiency.
4) Couple the photo-assisted water oxidation reaction to an enzymatic reaction through the use of cofactors such as NADH or methyl-viologen for the synthesis of eco-sustainable fuels such as methanol, ethanol, formaldehyde, methane, and formic acid (FA). In particular, FA is also an ideal precursor of hydrogen fuel and if we can implement protocells capable of autonomously and continuously producing FA from light, water and CO2, we could also explore the possibility of exploring the final step, that is the reduction of FA to hydrogen gas.
Through this multidisciplinary project, the student will develop skills in synthetic chemistry, polymer chemistry, soft materials chemistry, photocatalysis and biochemistry. The protocells that will be developed and their reactivity will be characterized via advanced spectroscopic (NMR, UV-vis and fluorescence) and microscopy (brightfield, darkfield, fluorescence, and electron) methods.
To fully develop the project the student will work for six months at Enphos, an industry in northeast of Italy that develops eco-sustainable systems to produce solar fuels and hydrogen. The student will also work for six months in the research group of Prof. Giovanni Finazzi (Commissariat a l’Energie Atomique et Aux Energies Alternative, Grenoble, France), where they will learn important biology techniques that will be integrated into the project to develop phototactic protocells.

References:
[1] J. Huang et al. Sci. Bull. 2018, 18, 1180-1186.
[2] P. Gobbo* et al. Front. Mol. Biosci., 2021, 8, 804717.
[3] C. Xu, et al. Mater. Today 2016, 19, 516-532.
[4] P. Gobbo, M. Bonchio, S. Mann, S. et al. Nat. Commun. 2020, 11, 41.
[5] M. Bonchio, M. Prato, et al. Nat. Chem. 2019, 11, 146-153.

Students interested in this project should contact Dr. Gobbo as soon as possible (pierangelo.gobbo@units.it). They should send their CV and explain (i) the reason for their interest in the project, and (ii) how their previous research experience could contribute to the project’s success.

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