Scientists are developing a method to efficiently produce hydrogen fuel from water using special photocatalyst materials that harness sunlight. Recently, they have added tiny metal nanoparticles to these materials to enhance efficiency. However, researchers disagree on how these metal nanoparticles aid the process. Some argue it results from significantly increased heating in confined spaces, while others believe it is due to very energetic carriers. This debate persists because characterizing the effect of local heating is challenging. This project aims to resolve this mystery by developing advanced imaging techniques to simultaneously measure thermal energy and gas (hydrogen and oxygen) production on a very small scale (billionths of a meter) with a controlled plasmonic nanoparticle array. By studying how tiny metal particles generate and share heat, this project will solve a key mystery: do these materials produce more hydrogen because they get hot, or because they create special high-energy particles? Understanding this will help us make better materials for turning sunlight into clean hydrogen fuel. A gold-titanium material system will be used for water splitting in a photoelectrochemical cell, and the nanoparticle array will be created using electron-beam lithography. A simultaneous temperature and gas detection technique will be developed using highly sensitive surface plasmon resonance (SPR) imaging. The imaging technique’s sensitivity will be enhanced through microscope and metamaterial design. This technique will be complemented with ultrafast spectroscopy, gas chromatography-mass spectrometry (GC-MS) or a gas analyzer, and computer simulation. The gas detection generated by SPR will be compared with GC-MS to establish an experimental relationship between simultaneous temperature and gas detection in SPR imaging. Ultra-fast measurements and computer simulations, incorporating advanced physics and chemistry models, will be employed to observe how rapidly these materials generate gas. The measurements will monitor the process from extremely brief moments to longer durations. This will enhance our understanding of heat transfer through the material, which is essential for improving process efficiency. The research outcome will be significant as it allows simultaneous measurement of temperature and gas generation from nanoparticles, providing a direct relationship between thermal energy and hydrogen generation. It will clarify the primary mechanism in enhanced hydrogen generation. This technique has applications in various fields, including clean energy, medicine, and chemical processes. The project aligns well with DOE Basic Energy Science priorities and will leverage the existing capabilities at Texas A&M University-Corpus Christi (TAMU-CC) and the state-of-the-art facilities at Sandia National Laboratories (SNL), preparing the project team thoroughly for this research. This collaboration holds great potential for new discoveries in how light interacts with materials to produce chemical reactions like hydrogen production. The project will foster a constructive partnership between TAMU-CC and SNL, aiding TAMU-CC, a Hispanic Serving Institution (HSI) in the Coastal Bend region of South Texas, in expanding its research capabilities in fundamental science. Students, a post-graduate researcher, and the lead scientist will benefit from access to cutting-edge equipment and the opportunity to exchange ideas with experts in the field.
