2026-05-23T01:52:41Zhttps://keep.lib.asu.edu/oai/request

oai:keep.lib.asu.edu:node-1586672024-12-23T18:01:48Zoai_pmh:alloai_pmh:repo_items

158667 https://hdl.handle.net/2286/R.I.62808 http://rightsstatements.org/vocab/InC/1.0/ 2020 313 pages Doctoral Dissertation Academic theses Text eng Wadsworth, Brian Lawrence Moore, Gary F Moore, Thomas A. Trovitch, Ryan J Arizona State University Doctoral Dissertation Chemistry 2020 Chemical modification of (semi)conducting surfaces with soft-material coatings containing electrocatalysts provides a strategy for developing integrated constructs that capture, convert, and store solar energy as fuels. However, a lack of effective strategies for interfacing electrocatalysts with solid-state materials, and an incomplete understanding of performance limiting factors, inhibit further development. In this work, chemical modification of a nanostructured transparent conductive oxide, and the III-V semiconductor, gallium phosphide, is achieved by applying a thin-film polymer coating containing appropriate functional groups to direct, template, and assemble molecular cobalt catalysts for activating fuel-forming reactions. The heterogeneous-homogeneous conducting assemblies enable comparisons of the structural and electrochemical properties of these materials with their homogeneous electrocatalytic counterparts. For these hybrid constructs, rational design of the local soft-material environment yields a nearly one-volt span in the redox chemistry of the cobalt metal centers. Further, assessment of the interplay between light absorption, charge transfer, and catalytic activity in studies involving molecular-catalyst-modified semiconductors affords models to describe the rates of photoelectrosynthetic fuel production as a function of the steady-state concentration of catalysts present in their activated form. These models provide a conceptual framework for extracting kinetic and thermodynamic benchmarking parameters. Finally, investigation of molecular ‘proton wires’ inspired by the Tyrosine Z-Histidine 190 redox pair in Photosystem II, provides insight into fundamental principles governing proton-coupled electron transfer, a process essential to all fuel-forming reactions relevant to solar fuel generation. Chemistry Energy Artificial Photosynthesis Electrocatalysis Photoelectrosynthesis Proton-Coupled Electron Transfer Solar Fuels Surface-Modification Hybrid Materials and Interfaces for Artificial Photosynthetic Assemblies