SusChEM: Photocatalytic Generation of Hydrogen from Water using Organic Nanofibril Catalysts

University Of Utah, Salt Lake City UT

Investigators

Abstract

PI: Ling Zang Proposal Number: 1502433 Hydrogen gas is a clean and zero-carbon fuel which can be converted to electrical power using a device called a fuel cell for electric vehicle or industrial applications. Most of the hydrogen gas produced today comes from processing of natural gas, primarily from fossil fuel resources. However, future sources of hydrogen will need to come from renewable resources if they are to become part of our sustainable energy future. The goal of this project is to develop inexpensive, polymer-based materials that will convert water into hydrogen gas using sunlight to drive the reaction. In the proposed research, electrically conductive organic polymers will be extruded into nanometer diameter fibrils designed to capture the suns photons. Catalyst materials imbedded in the polymer help to split apart the water molecule to hydrogen and oxygen gas using these absorbed photons through a process called photocatalysis. The research will make and test the performance of these materials for generation of hydrogen from water. Students involved in this project will be trained at the interface of renewable energy and nanotechnology. The project will also develop hydrogen production demonstration for Natural History Museum of Utah to illustrate renewable energy research to public audiences. The goal of this research is to synthesize and characterize the performance of new organic polymer nanofibril based photocatalytic materials for the splitting of water into hydrogen gas. These nanofibers, which contain both polymer and metal co-catalyst nanoparticles, are multifunctional, combining the properties of tunable band structure, visible spectral response, and large surface area. In the research plan, the organic polymer nanofibers will be synthesized from building-block molecules containing donor-acceptor moieties responsive to wide range of visible light. The donor-acceptor material interface will also be engineered for increased charge separation upon illumination, as well as for the efficient transport of the photo-generated electrons to the co-catalyst sites that convert protons to hydrogen. This interface will also be engineered to maximize the intake of the photogenerated electrons while preventing their recombination with cationic radicals. Time-resolved electron spin resonance measurements will characterize how interfacial electron-scavenging depends on particle size and energy level alignment in the polymer and co-catalyst. Hydrogen production activity of the synthesized nanofibril photocatalysts will be correlated to quantum efficiency, turnover numbers, and dependence on irradiation wavelength. As part of the educational activities, workshops based on solar fuels and solar photovoltaics topics will be offered through Utah Science Center and the NSF-sponsored Nanodays at Nano Institute of Utah.