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Catalysts accelerate chemical transformations, but the ability to effectively interface them with surfaces for driving industrially relevant reactions using electricity or sunlight as a power source remains a major challenge. This presentation will report on recent efforts from our research group aimed at developing molecular surface coatings for photoactivating chemical transformations that include capturing, converting, and storing solar energy as a fuel. Addressing this obstacle improves fundamental understanding of catalysis in complex environments and enables technological advancements that depend on the precise control and selectivity of nanoscale components. By designing extended environments for the coordination of molecular catalysts, key features of biological enzymes such as extended ligation spheres, channels for substrate delivery and product removal, as well as regeneration strategies can be integrated with the design and synthesis of human-engineered catalysts. Functionality of these hybrid materials for applications in semiconductor photoelectrochemistry and photocatalysis are examined using electrochemical characterization techniques and an improved understanding of structure and function relationships is achieved using surface-sensitive characterization methods, including grazing angle Fourier transform infrared and X-ray photoelectron spectroscopies.
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Integrated Photocatalytic Materials for Fuel Production
Controlling matter and information across the nano-, meso-, and macro-scales is a challenge for science and the imagination. In this presentation, we highlight recent advances in our research efforts to develop synthetic methodologies for constructing an integrated photocathode for light activating chemical transformations that include capturing, converting, and storing solar energy as fuel. A recent example involves development of a direct one-step method to chemically graft porphyrin catalysts that chemically transform water to hydrogen as well as carbon dioxide to carbon monoxide onto a visible-light-absorbing gallium phosphide (GaP) semiconductor. The porphyrin complexes are prepared using a synthetic strategy that yields a tetrapyrrole macrocycle with a pendant 4-vinylphenyl attachment group. This structural modification allows use of the UV-induced immobilization chemistry of olefins to attach intact metalloporphyrin complexes to the semiconductor surface. Solar hydrogen production is demonstrated via photoelectrochemical testing in pH neutral aqueous solutions under simulated solar illumination. Key features of the constructs presented here include use of metalloporphyrins with built-in chemical sites for direct grafting to a GaP semiconductor, creating novel hybrid photoactive assemblies capable of converting photonic energy to fuel.
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- Award ID(s):
- 1653982
- PAR ID:
- 10082171
- Date Published:
- Journal Name:
- Materials Research Society symposia proceedings
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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