Daniel George Nocera (born July 3, 1957) is an American chemist, currently the Patterson Rockwood Professor of Energy in the Department of Chemistry and Chemical Biology at Harvard University.

[3][4] Nocera has opened up new areas of basic research into the mechanisms of energy conversion in biology and chemistry, including the study of multielectron excited states and proton coupled electron transfer (PCET).

[16] In February 2012, Nocera agreed to move his research group to the Department of Chemistry and Chemical Biology at Harvard University in Cambridge, Massachusetts,[1][17] where he became the Patterson Rockwood Professor of Energy.

[1] Nocera's major areas of interest are in biological and chemical energy conversion, focusing on mechanisms at the molecular level and the photogeneration of hydrogen and oxygen.

[18] His work on artificial photosynthesis grows out of his basic research into mechanisms of energy conversion in biology and chemistry, particularly those involving multielectron excited states and proton coupled electron transfer (PCET).

[24][25] Nocera's early work on two-electron bonds and multielectron excited states is considered to have established new paradigms in excited-state chemistry.

The absorption of light caused the two RhII-X bonds of a dirhodium compound to break, resulting in an active rhodium catalyst which was able to react with hydrohalic acids.

[35] In 2009, Nocera formed Sun Catalytix, a startup to develop a prototype design for a system to convert sunlight into storable hydrogen which could be used to produce electricity.

Such a system would require both technological and commercial breakthroughs to create economically viable components for hydrogen storage, solar panels, and fuel cells.

[38] In 2011, Nocera and his research team announced the creation of the first practical "artificial leaf": an advanced solar cell the size of a playing card, capable of splitting water into oxygen and hydrogen with ten times the efficiency of natural photosynthesis.

"[45] Nonetheless, researchers at Harvard and elsewhere continue to investigate the possibilities of the artificial leaf, looking for ways to reduce costs and increase efficiency.

[2][51] Other contributions include synthesis of an S = 1/2 kagome lattice, of interest to the study of spin-frustrated systems and conduction mechanisms in superconductors;[52] development of microfluidic optical chemosensors for use on the microscale and nanoscale;[53][54] and molecular tagging velocimetry (MTV) techniques.