Photosynthesis harvests solar energy and stores it in chemical forms. When used to produce fuels, this process promises a solution to challenges associated with the intermittent nature of sunlight. Theoretical studies show that photosynthesis can be efficient and inexpensive. To achieve this goal, we need materials with suitable properties of light absorption, charge separation, chemical stability, and catalytic activity. For large-scale implementations, the materials should also be made of earth abundant elements. Due to the intricacy of these considerations, a material that meets all requirements simultaneously is absent and, as a result, existing photosynthesis is either inefficient or costly or both, creating a critical challenge in solar energy research. At Boston College, we have developed strategies to combat this challenge through rational material design and precise synthesis control. Guided by an insight that complex functionalities may be obtained by combining multiple material components through homo- or hetero-junctions, we have produced a number of material combinations aimed at solving fundamental challenges common in inorganic semiconductors such as poor charge collection, mismatch of energy levels, and weak light absorption. Much of our effort is focused on using these materials for solar water splitting. More recently we have started devising highly specific reaction routes for carbon dioxide photofixation. Exciting new progress in a technologically relevant field of rechargeable batteries has been made by us, as well.
Representative Key Publications:
Rui Liu, Guangbi Yuan, Candice Joe, Ted Lightburn, Kian L. Tan, Dunwei Wang, “Si Nanowires as Photoelectrode for Carbon Dioxide Fixation,” Angew. Chem. Int. Ed. 2012
Yongjing Lin, Sa Zhou, Stafford Sheehan, Dunwei Wang, “Nanonet-Based Hematite Heteronanostructures for Efficient Solar Water Splitting,” J. Am. Chem. Soc. 2011
Sa Zhou, Xiaohua Liu, Yongjing Lin, Dunwei Wang, “Spontaneous Growth of Highly Conductive Two-dimensional Single Crystalline TiSi2 Nanonets,” Angew. Chem. Int. Ed. 2008