His research focus is chemical transport and fate in a multimedia environment. He is especially interested in nutrient retention in soil, groundwater, river and lake by the coupled hydrological and biogeochemical processes. His teaching interests at Duke Kunshan include environmental science, biogeochemistry, Earth science, and ecology.

He has published articles in prestigious journals and served as UNC representative for the Consortium of Universities for the Advancement of Hydrologic Science. He has also served on proposal review panels for the U.S. National Science Foundation. He is a recipient of Wachovia Environmental Award and Excellence in Refereeing from the American Geophysical Union.

Gu has a B.Sc. in environmental science from Nanjing University, an M.Sc. in environmental science from Sun Yat-sen University and a Ph.D. from the University of Virginia. He served as a postdoc researcher at the University of California, Berkeley. Before joining Duke Kunshan, he held faculty positions at Appalachian State University and Beijing Normal University.