A Caltech Library Service

Strategies for Enabling Stable and Efficient (Photo)Electrochemical Water Splitting


Ifkovits, Zachary Philip (2023) Strategies for Enabling Stable and Efficient (Photo)Electrochemical Water Splitting. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/jt8t-w739.


The electrolysis of water splits H₂O into its constituent parts, generating H₂ fuel and O₂ as a by-product. Although electrolysis has been known since late 1700s and has a consistently expanding industrial capacity, several barriers still exist to its widespread utilization as a clean method of generating hydrogen for industrial uses or as a grid-scale energy storage chemical. Among these, the materials and costs constraints surrounding the use of precious metal catalysts and expenses associated with balance-of-system costs are of primary importance. In this thesis, the first point is addressed by utilizing earth-abundant catalysts for chemical, electrochemical, and photoelectrochemical water splitting reactions. Specifically, MnySb1-yOx catalysts were synthesized for use as both cerium-mediated chemical water oxidation catalysts and as electrochemical water oxidation catalysts, furthering steps towards removing Ir from industrial electrolysis devices. Addition of Sb was shown to stabilize reactive Mn centers in these configurations, offering enhanced stability over pure Mn oxide catalysts. Reduction of electrolyzer balance-of-system costs were addressed in this thesis through the integration of multiple components of a solar-powered electrolysis system into a single, integrated photoelectrochemical water splitting device. Specifically, electrodeposition conditions were shown to affect the spontaneous mesostructuring of Ni-P hydrogen evolution catalysts on silicon photocathodes, leading to enhanced transmission of light to the semiconductor substrate. Furthermore, Y₂SiO₅ protective layers were shown to mitigate the corrosion of Si photocathodes in alkaline environments, an electrochemical environment known to be destructive towards silicon.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Electrolysis, Earth-Abundant Catalysis, Water-Splitting, Photoelectrochemistry
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemical Engineering
Thesis Availability:Not set
Research Advisor(s):
  • Lewis, Nathan Saul
Thesis Committee:
  • Flagan, Richard C. (chair)
  • Shapiro, Mikhail G.
  • Wang, Zhen-Gang
  • Lewis, Nathan Saul
Defense Date:31 March 2023
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
Department of Energy (DOE)DE-SC0022087
Record Number:CaltechTHESIS:05132023-220300179
Persistent URL:
Related URLs:
URLURL TypeDescription for Chapter 1 for Chapter 2
Ifkovits, Zachary Philip0000-0003-2538-0794
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:15167
Deposited By: Zachary Ifkovits
Deposited On:23 May 2023 22:42
Last Modified:08 Nov 2023 00:31

Full text not available from this repository.

Repository Staff Only: item control page