Doctoral Dissertations


Xi Cao


”Water splitting has been widely considered to be an efficient way to generate sustainable and renewable energy resources in fuel cells, metal-air batteries and other energy conversion devices. Exploring efficient electrocatalysts to expedite the anodic oxygen evolution reaction (OER) is a crucial task that needs to be addressed to boost the practical application of water splitting. This research focuses on the identification of OER electrocatalysts by systematically designing non-stochiometric mixed transition metal-based selenide OER electrocatalysts through combinatorial electrodeposition and investigation of selenide-based naturally occurring minerals as effective OER electrocatalyst. Paper I describes the study of Ni-Fe-Co selenides as OER catalysts by combinatorial electrodeposition and the best composition (Ni0.25Fe0.68Co0.07)3Se4 with the lowest overpotential. Paper II presents the exploration of Co-Ni-Cu selenide system through combinatorial electrodeposition of 66 different compositions as highly efficient OER electrocatalysts and the best quaternary (Co0.21Ni0.25Cu0.54)3Se2 showing a similar crystal structure as its parent compound Cu3Se2. Paper III introduces the Fe-Co-Cu selenide system investigated through combinatorial electrodeposition, and the optimal quaternary is identified as (Fe0.48Co0.38Cu0.14)Se. Paper IV presents CuCo2Se4 as high-efficiency bifunctional electrocatalyst for full water splitting and conducted DFT calculation of surface dependent OER activity on (100) and (111) facets. Paper V introduces the hydrothermal synthesis of naturally-occurring mineral Tyrrellite Cu(Co0.68Ni0.32)2Se4 as highly-efficient OER electrocatalyst. Paper VI describes three naturally occurring copper selenides (Cu2Se, Cu3Se2 and CuSe2) as OER electrocatalyst and performed DFT calculation to understand their catalytic activity trend”--Abstract, page iv.


Nath, Manashi

Committee Member(s)

Woelk, Klaus
Winiarz, Jeffrey G.
Choudhury, Amitava
Medvedeva, Julia E.
Liang, Xinhua



Degree Name

Ph. D. in Chemistry


The authors would like to acknowledge financial support from National Science Foundation (DMR 1710313), American Chemical Society Petroleum Research Fund (54793-ND10), and Energy Research and Development Center (ERDC) Missouri S&T.


Missouri University of Science and Technology

Publication Date

Summer 2019

Journal article titles appearing in thesis/dissertation

  • Phase exploration and identification of multinary transition metal selenides as high-efficiency oxygen evolution electrocatalysts through combinatorial electrodeposition
  • Identifying high-efficiency oxygen evolution electrocatalysts from Co-Ni-Cu based selenides through combinatorial electrodeposition
  • Expanding multinary selenide based high-efficiency oxygen evolution electrocatalysts through combinatorial electrodeposition: Case study with Fe-Cu-Co selenides
  • Copper cobalt selenide as a high-efficiency bifunctional electrocatalyst for overall water splitting: Combined experimental and theoretical study
  • Tyrrellite as a novel and sustainable efficient electrocatalysts for oxygen evolution generation
  • Naturally occurring minerals as novel oxygen evolution reaction electrocatalysts: Berzelianite, umangite and krut'aite (Cu₂Se, Cu₃Se₂ and CuSe₂) generation


xvii, 294 pages

Note about bibliography

Includes bibliographic references.


© 2019 Xi Cao, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 12003

Electronic OCLC #