Dr. Zhang's research interests focus on energy and the environment. He studies the effects of airborne particulate matters (PM) and gaseous pollutants on air quality, climate change and ecosystem, using numerical models and experimental techniques. One particular area he is working on is environmental nanoparticles. Nanoparticle pollution affects public health by depositing deeper in our lungs and moving into the blood circulation.

These nanoparticles can also grow into cloud condensation nuclei (CCN). Changes in CCN concentration may affect cloud reflectivity and lifetime, thus perturbing the energy balance of the planet. His research in this area focuses on characterizing various emission sources and their transformation in the atmosphere, especially the rapid changes in the first few minutes after emission. One important goal is to establish a source-to-receptor relationship for airborne nanoparticles. The "receptor" refers to either humans or the climate system.

Dr. Zhang's group has developed CTAG (which stands for Comprehensive Turbulent Aerosol dynamics and Gas chemistry), an environmental turbulent reacting flow model, to simulate the transport and transformation of multiple pollutants in complex environments. In particular, he aims to develop a mechanistic understanding on 1) near-road air pollution and its potential mitigation strategies, 2) the effects of turbulent mixing on particulate emission measurements, and 3) the impacts of plume processing on regional air quality and climate simulations.