Prof. Zhao is currently Professor and Chair of the Civil, Construction, and Environmental Engineering at San Diego State University, California, USA. Dr. Zhao is internationally recognized for his pioneering work in developing new stabilized nanoparticles for the in situ degradation of organic contaminants and the neutralization of metals, metalloids and radionuclides in soil and water. Dr. Zhao's group is also appreciated for its pioneering work on the development of adsorption photocatalysts for the destruction of the so-called persistent organic pollutants, such as per- and polyfluoroalkyl substances (PFAS), in polluted waters.