He is well known for his work on bacterial photosynthetic reaction centres,[1][2][3] hydrogenase enzymes,[4] and the oxygen-evolving complex[5][6] using a variety of biophysical techniques.

From 1983 to 1984 he worked as a Max Kade Fellow at UC San Diego in the Physics Department with George Feher on EPR and ENDOR in photosynthesis.

He and his group studied light-induced chlorophyll donor[2] and quinone acceptor radical ions[3] of the primary electron-transfer chain.

Later his research focused on the water splitting cycle (S-states) of photosystem II using advanced multifrequency pulse EPR, ENDOR and EDNMR techniques.

[15][16][17] Further work using advanced Pulse EPR techniques, such as EDNMR, has led to information on the binding of water[18] and a proposal of an efficient O-O bond formation in the final state of the cycle.

[15][6] Extensive work was performed on the [NiFe]-Hydrogenase where the magnetic tensors were measured and related to quantum chemical calculations.

[22] Using artificial maturation, the protein could be generated without the co-factor (apoprotein) using E. coli mutagenesis and a synthetically created active site could be inserted,[22][23][24] which has opened new vistas in hydrogenase research.