Understanding Materials for Solar Fuel Production

Solar energy represents a renewable source that has the potential to meet our ever-increasing energy demand without devastating the environment. One approach to harvesting the energy is to carry out light-powered chemical reactions. Thermodynamically uphill, these reactions produce energetic chemicals that can be used as fuels, promising a large-scale energy storage solution.
To enable these reactions, we need materials that can absorb light, separate charges, and catalyze specific chemistries. The materials should be made of earth-abundant elements to allow for large-scale implementations. They also need to be resistant against photo corrosion. To date, a low-cost, long-lasting material that can produce solar fuels with a high efficiency remains elusive.
In this talk, we present our efforts aimed at understanding what limits the performance of materials in solar fuel generation reactions. Within the context of photoanode and photocathode, we show how the photoelectrode properties are changed by introducing material components designed for improving charge transport, surface potential accumulation, and interface kinetics, respectively. We also demonstrate that highly complex organic molecules can be produced by photoreduction of CO2, in a fashion closely mimicking the dark reactions in natural photosynthesis.
This body of work is enabled by our ability to synthesize materials with precisely controlled surfaces and interfaces using methods such as atomic layer deposition. Our results highlight the importance of understanding thermodynamic and kinetic factors in complex systems such as that for solar fuel production separately. Detailed knowledge generated by our research contributes to the goal of realizing low-cost, high-efficiency artificial photosynthesis.

Speaker: Dunwei Wang, Boston College