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You searched for subject:(Photosynthesis Microfabrication). Showing records 1 – 2 of 2 total matches.

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1. Ren, Xiang. Cell-Free Artificial Photosynthesis System.

Degree: 2016, Drexel University

The objective of this research is to create a cell-free artificial platform for harvesting light energy and transforming the energy to organic compounds. In order to achieve this objective, we took the approach of mimicking the photosynthetic processes of a plant leaf and integrating them into a compact system using microfabrication technology. Photosynthesis consists of two parts: light reaction and dark reaction. During the light reaction, light energy is transformed to chemical energy in ATP that is a biological energy source, while during the dark reaction. Carbon dioxide is absorbed and used to synthesize organic compounds such as glucose and fructose. Many scientists had tried to realize artificial photosynthesis for energy harvesting for decades. However, most of the previous systems were simply based on light reaction and produced less desirable energy sources, such as explosive hydrogen gas and unstable electricity. Other works had been reported that combined both light and dark reactions to produce useful organic compounds, but they were all based on utilizing living cells that were difficult to maintain and were not reusable. We developed a cell-free artificial platform conducting both light and dark reactions. To the best of our knowledge, such a device had not been reported so far. This device was able to harvest light energy and transform the energy to organic compounds, mimicking a plant leaf. We envision integrating the "artificial leaves" to create a compact energy harvesting system with a promising efficiency. In order to create an artificial photosynthesis device, we had come up with four specific parts as follows. Part 1: Light reaction was realized in a microfluidic platform that consists of two fluid chambers separated by a planar membrane with embedded proteins that convert light energy into ATP. Four different materials were investigated as potential membrane materials and the optimal (most stable) material was identified through impedance spectroscopy. Since these membrane materials were very soft, it was challenging to integrate them in a microfluidic platform. Diverse support materials and fabrication techniques were investigated to identify the optimal fabrication process. Once the best membrane material was identified and a microfluidic platform was constructed, we would have light-converting proteins embedded in the membrane followed by the evaluation its light reaction performance. Part 2: Dark reaction was realized in another microfluidic platform porous PDMS cubes as gas-liquid interface media. We used porous PDMS as a gas-liquid interface between microfluidic channels to create a "one-way" diffusion path for carbon dioxide. The CO2 transport was evaluated based on pH change and successful CO2 transport would produce precursors (C3 compounds) for glucose production. Part 3: Glucose synthesis and storage unit was developed by mimicking sponge mesophyll found in a leaf (dicotyledons leaf). Chitosan porous structures with interconnected pores were used for this purpose and they were… Advisors/Committee Members: Zhou, Jack, Noh, Hongseok (Moses).

Subjects/Keywords: Mechanical engineering; Photosynthesis – Microfabrication; Photosynthesis – Simulation methods

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ren, X. (2016). Cell-Free Artificial Photosynthesis System. (Thesis). Drexel University. Retrieved from http://hdl.handle.net/1860/idea:6673

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Ren, Xiang. “Cell-Free Artificial Photosynthesis System.” 2016. Thesis, Drexel University. Accessed July 03, 2020. http://hdl.handle.net/1860/idea:6673.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Ren, Xiang. “Cell-Free Artificial Photosynthesis System.” 2016. Web. 03 Jul 2020.

Vancouver:

Ren X. Cell-Free Artificial Photosynthesis System. [Internet] [Thesis]. Drexel University; 2016. [cited 2020 Jul 03]. Available from: http://hdl.handle.net/1860/idea:6673.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ren X. Cell-Free Artificial Photosynthesis System. [Thesis]. Drexel University; 2016. Available from: http://hdl.handle.net/1860/idea:6673

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Larrazábal, Gastón O. Transition Metal-Based Catalysts Modified with p-Block Elements for the Electrochemical Reduction of CO2.

Degree: 2018, ETH Zürich

Avoiding the most serious effects of climate change is one of the greatest technical and socio-political challenges of our time. At the present rate of anthropogenic CO2 emissions, in less than two decades mankind will lose the opportunity to limit the global temperature increase to 2 °C (as stated in the Paris Agreement), a fact that makes carbon dioxide an urgent target for recycling efforts. In this context, the combination of the electrochemical reduction of CO2 (eCO2RR) with carbon-neutral energy sources opens the door for the valorization of carbon dioxide as a medium for energy storage and as a source for the production of building blocks in a fossil fuel-free chemical industry. In particular, the efficient reduction of CO2 to CO would provide a versatile compound for the production of liquid fuels and plastics by established industrial processes. However, a key challenge for the eCO2RR on its way toward technological viability is the development of highly active and robust electrocatalysts capable of targeting a single CO2 reduction product and of inhibiting the competing hydrogen evolution reaction (HER) in aqueous media. Theoretical insights indicate that the key to unlocking breakthrough advances in catalytic performance for the eCO2RR lies in breaking the sub-optimal scaling relations between reaction intermediates that exist on transition metal surfaces. In this context, this thesis work is aimed at exploring the emergence of synergistic interactions in multicomponent materials as a design strategy for the development of improved eCO2RR catalysts, with an emphasis on understanding how the introduction of p-block elements modulates the activity and selectivity of transition metal-based catalysts for this reaction. First steps are aimed at evaluating whether the intrinsic selectivity for CO of silver electrodes can be enhanced by an interaction with indium, which is a poor HER catalyst. To this end, a comprehensive set of Ag-In electrocatalysts with different architectures is synthesized and tested, ranging from bulk intermetallic compounds to Ag nanoparticles supported on In2O3 and In(OH)3. Bulk Ag9In4 and AgIn2 alloys prepared by a succession of electrodeposition and annealing steps show a catalytic performance very similar to that of pure In, which is attributed to the surface enrichment of In in these materials. In contrast, the supported catalysts exhibit an enhanced current efficiency for CO at moderate overpotential, evidencing a synergistic effect between the metal nanoparticles and the oxidic supports. This effect is particularly marked with In(OH)3 as support, which unlike In2O3 is characterized by a kinetic impairment toward reduction to metallic In under eCO2RR conditions. In a following step, this approach is extended to the study of Cu-In catalysts. In this regard, the structure of Cu-In nanoalloys prepared by the in situ reduction of the CuInO2 delafossite and of In(OH)3-supported Cu nanoparticles evolves substantially over several electrocatalytic cycles, in parallel with an… Advisors/Committee Members: Pérez-Ramírez, Javier, Kovalenko, Maksym V..

Subjects/Keywords: Heterogeneous catalysis; Electrochemistry; Electrocatalysis; Carbon dioxide reduction; Carbon dioxide utilization; Alloys; Microfabrication; Solar fuels; Artificial photosynthesis; Catalyst restructuring; Interfaces and thin films; Photolithography; info:eu-repo/classification/ddc/540; Chemistry

…photolithography-based microfabrication process for structured electrodes with controlled geometry and… …forward the development of this class of materials. The microfabrication process is applied to… …used in this reaction, and the microfabrication of structured electrodes is shown as a… …carried out the microfabrication process of Chapter 6. T. Shinagawa conducted the main synthetic… …Introduction photosynthesis. [7,14,17] 5 In broad terms, a photocatalytic reaction… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Larrazábal, G. O. (2018). Transition Metal-Based Catalysts Modified with p-Block Elements for the Electrochemical Reduction of CO2. (Doctoral Dissertation). ETH Zürich. Retrieved from http://hdl.handle.net/20.500.11850/251660

Chicago Manual of Style (16th Edition):

Larrazábal, Gastón O. “Transition Metal-Based Catalysts Modified with p-Block Elements for the Electrochemical Reduction of CO2.” 2018. Doctoral Dissertation, ETH Zürich. Accessed July 03, 2020. http://hdl.handle.net/20.500.11850/251660.

MLA Handbook (7th Edition):

Larrazábal, Gastón O. “Transition Metal-Based Catalysts Modified with p-Block Elements for the Electrochemical Reduction of CO2.” 2018. Web. 03 Jul 2020.

Vancouver:

Larrazábal GO. Transition Metal-Based Catalysts Modified with p-Block Elements for the Electrochemical Reduction of CO2. [Internet] [Doctoral dissertation]. ETH Zürich; 2018. [cited 2020 Jul 03]. Available from: http://hdl.handle.net/20.500.11850/251660.

Council of Science Editors:

Larrazábal GO. Transition Metal-Based Catalysts Modified with p-Block Elements for the Electrochemical Reduction of CO2. [Doctoral Dissertation]. ETH Zürich; 2018. Available from: http://hdl.handle.net/20.500.11850/251660

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