Deposition and characterization of various materials on Si microwires for the photoelectrochemical reduction of NAD+
(2026) KEMR30 20261Department of Chemistry
- Abstract
- The use of NADH as fuel for industrial enzymatic reactions has gained large interest over the years. However, novel catalytic materials and process are required to produce NADH from NAD+. This thesis investigated the deposition and characterization of catalytic materials on p-type silicon microwire (SiMW) photoelectrodes for the photoelectrochemical reduction of NAD⁺ to enzymatically active NADH. Iron aminoclay (FeAC), nickel oxide (NiOx), and hematite (α-Fe₂O₃) were explored as potential co-catalysts using a variety of deposition and surface functionalization strategies. FeAC was successfully synthesized and characterized; however, its high water solubility prevented stable attachment under aqueous reaction conditions. NiOx thin films... (More)
- The use of NADH as fuel for industrial enzymatic reactions has gained large interest over the years. However, novel catalytic materials and process are required to produce NADH from NAD+. This thesis investigated the deposition and characterization of catalytic materials on p-type silicon microwire (SiMW) photoelectrodes for the photoelectrochemical reduction of NAD⁺ to enzymatically active NADH. Iron aminoclay (FeAC), nickel oxide (NiOx), and hematite (α-Fe₂O₃) were explored as potential co-catalysts using a variety of deposition and surface functionalization strategies. FeAC was successfully synthesized and characterized; however, its high water solubility prevented stable attachment under aqueous reaction conditions. NiOx thin films were deposited by sol-gel spin coating, yielding uniform and crystalline coatings on flat silicon substrates, but non-uniform coverage on SiMW. Hematite coatings were prepared through both sol-gel and hydrothermal methods, with an optimized Fe-urea hydrothermal process producing the most homogeneous particle growth on SiMW arrays. Electrochemical and photoelectrochemical evaluation indicated that TiN-coated SiMW and hematite-modified SiMW, as the most promising of the materials, encountered difficulties promoting the solar-driven NAD⁺ regeneration. (Less)
- Popular Abstract
- Modern society increasingly relies on sustainable technologies that can efficiently use energy and produce valuable chemicals. One important molecule in biological systems is NADH, which acts as a carrier of energy and electrons and is required in many enzymatic reactions. Because NADH is consumed during these processes, efficient methods for regenerating it are needed for future applications in biotechnology and green chemistry.
This project explored the use of silicon microwires as light-absorbing structures for the photoelectrochemical regeneration of NADH from its oxidized form, NAD⁺. Silicon microwires can capture sunlight and convert it into electrical energy, making them attractive candidates for solar-driven chemical reactions. To... (More) - Modern society increasingly relies on sustainable technologies that can efficiently use energy and produce valuable chemicals. One important molecule in biological systems is NADH, which acts as a carrier of energy and electrons and is required in many enzymatic reactions. Because NADH is consumed during these processes, efficient methods for regenerating it are needed for future applications in biotechnology and green chemistry.
This project explored the use of silicon microwires as light-absorbing structures for the photoelectrochemical regeneration of NADH from its oxidized form, NAD⁺. Silicon microwires can capture sunlight and convert it into electrical energy, making them attractive candidates for solar-driven chemical reactions. To improve the performance of these systems, different co-catalyst materials including nickel oxide and hematite were deposited onto the microwire surfaces.
Several deposition approaches were investigated and optimized to achieve stable and uniform coatings. Material characterization techniques such as scanning electron microscopy, X-ray diffraction and electrochemical measurements were used to understand how the deposited materials formed and behaved on the silicon structures. While challenges were encountered in obtaining homogeneous coatings and achieving successful NAD⁺ reduction, the work provided important insights into the relationship between material preparation, surface structure and photoelectrochemical performance.
The findings contribute to the development of improved solar-driven catalytic systems and highlight both the opportunities and limitations of integrating functional materials onto complex microstructured surfaces. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/student-papers/record/9248154
- author
- Christoforou, Alexandros LU
- supervisor
-
- Axl Eriksson LU
- organization
- course
- KEMR30 20261
- year
- 2026
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- NAD regeneration, Silicon microwires, deposition, chemical physics
- language
- English
- id
- 9248154
- date added to LUP
- 2026-08-14 11:47:37
- date last changed
- 2026-08-14 11:47:37
@misc{9248154,
abstract = {{The use of NADH as fuel for industrial enzymatic reactions has gained large interest over the years. However, novel catalytic materials and process are required to produce NADH from NAD+. This thesis investigated the deposition and characterization of catalytic materials on p-type silicon microwire (SiMW) photoelectrodes for the photoelectrochemical reduction of NAD⁺ to enzymatically active NADH. Iron aminoclay (FeAC), nickel oxide (NiOx), and hematite (α-Fe₂O₃) were explored as potential co-catalysts using a variety of deposition and surface functionalization strategies. FeAC was successfully synthesized and characterized; however, its high water solubility prevented stable attachment under aqueous reaction conditions. NiOx thin films were deposited by sol-gel spin coating, yielding uniform and crystalline coatings on flat silicon substrates, but non-uniform coverage on SiMW. Hematite coatings were prepared through both sol-gel and hydrothermal methods, with an optimized Fe-urea hydrothermal process producing the most homogeneous particle growth on SiMW arrays. Electrochemical and photoelectrochemical evaluation indicated that TiN-coated SiMW and hematite-modified SiMW, as the most promising of the materials, encountered difficulties promoting the solar-driven NAD⁺ regeneration.}},
author = {{Christoforou, Alexandros}},
language = {{eng}},
note = {{Student Paper}},
title = {{Deposition and characterization of various materials on Si microwires for the photoelectrochemical reduction of NAD+}},
year = {{2026}},
}