{"id":{"repo_id":"must-thes","oai_identifier":"oai:scholarsmine.mst.edu:doctoral_dissertations-4094"},"canonical_url":"https://search.dev.ndltd.org/etd/must-thes/oai:scholarsmine.mst.edu:doctoral_dissertations-4094","repository":{"repo_id":"must-thes","name":"Missouri University of Science and Technology","base_url":"https://scholarsmine.mst.edu/do/oai/"},"display":{"title":"Designing novel multinary transition metal selenides as high-efficiency oxygen evolution reaction electrocatalysts and investigating surface properties","abstract":"<p>”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 (Ni<sub>0.25</sub>Fe<sub>0.68</sub>Co<sub>0.07</sub>)<sub>3</sub>Se<sub>4</sub> 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 (Co<sub>0.21</sub>Ni<sub>0.25</sub>Cu<sub>0.54</sub>)<sub>3</sub>Se<sub>2</sub> showing a similar crystal structure as its parent compound Cu<sub>3</sub>Se<sub>2</sub>. Paper III introduces the Fe-Co-Cu selenide system investigated through combinatorial electrodeposition, and the optimal quaternary is identified as (Fe<sub>0.48</sub>Co<sub>0.38</sub>Cu<sub>0.14</sub>)Se. Paper IV presents CuCo<sub>2</sub>Se<sub>4</sub> 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(Co<sub>0.68</sub>Ni<sub>0.32</sub>)<sub>2</sub>Se<sub>4</sub> as highly-efficient OER electrocatalyst. Paper VI describes three naturally occurring copper selenides (Cu<sub>2</sub>Se, Cu<sub>3</sub>Se<sub>2</sub> and CuSe<sub>2</sub>) as OER electrocatalyst and performed DFT calculation to understand their catalytic activity trend”--Abstract, page iv.</p>","abstract_html":"&lt;p&gt;”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 (Ni&lt;sub&gt;0.25&lt;/sub&gt;Fe&lt;sub&gt;0.68&lt;/sub&gt;Co&lt;sub&gt;0.07&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;Se&lt;sub&gt;4&lt;/sub&gt; 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 (Co&lt;sub&gt;0.21&lt;/sub&gt;Ni&lt;sub&gt;0.25&lt;/sub&gt;Cu&lt;sub&gt;0.54&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;Se&lt;sub&gt;2&lt;/sub&gt; showing a similar crystal structure as its parent compound Cu&lt;sub&gt;3&lt;/sub&gt;Se&lt;sub&gt;2&lt;/sub&gt;. Paper III introduces the Fe-Co-Cu selenide system investigated through combinatorial electrodeposition, and the optimal quaternary is identified as (Fe&lt;sub&gt;0.48&lt;/sub&gt;Co&lt;sub&gt;0.38&lt;/sub&gt;Cu&lt;sub&gt;0.14&lt;/sub&gt;)Se. Paper IV presents CuCo&lt;sub&gt;2&lt;/sub&gt;Se&lt;sub&gt;4&lt;/sub&gt; 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(Co&lt;sub&gt;0.68&lt;/sub&gt;Ni&lt;sub&gt;0.32&lt;/sub&gt;)&lt;sub&gt;2&lt;/sub&gt;Se&lt;sub&gt;4&lt;/sub&gt; as highly-efficient OER electrocatalyst. Paper VI describes three naturally occurring copper selenides (Cu&lt;sub&gt;2&lt;/sub&gt;Se, Cu&lt;sub&gt;3&lt;/sub&gt;Se&lt;sub&gt;2&lt;/sub&gt; and CuSe&lt;sub&gt;2&lt;/sub&gt;) as OER electrocatalyst and performed DFT calculation to understand their catalytic activity trend”--Abstract, page iv.&lt;/p&gt;","abstract_has_math":false,"creators":["Cao, Xi"],"institution":"Missouri University of Science and Technology","degree_name":"Ph. D. in Chemistry","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":null,"date_issued":"","date_published":null,"updated_at":"2026-07-24T03:18:09Z","subjects":["Inorganic Chemistry"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsmine.mst.edu/doctoral_dissertations/3089","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Cao, Xi"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:type","label":"Dc Type","values":["Dissertation - Open Access"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. D. in Chemistry"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Missouri University of Science and Technology"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Inorganic Chemistry"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsmine.mst.edu/doctoral_dissertations/3089"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["<p>”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 (Ni<sub>0.25</sub>Fe<sub>0.68</sub>Co<sub>0.07</sub>)<sub>3</sub>Se<sub>4</sub> 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 (Co<sub>0.21</sub>Ni<sub>0.25</sub>Cu<sub>0.54</sub>)<sub>3</sub>Se<sub>2</sub> showing a similar crystal structure as its parent compound Cu<sub>3</sub>Se<sub>2</sub>. Paper III introduces the Fe-Co-Cu selenide system investigated through combinatorial electrodeposition, and the optimal quaternary is identified as (Fe<sub>0.48</sub>Co<sub>0.38</sub>Cu<sub>0.14</sub>)Se. Paper IV presents CuCo<sub>2</sub>Se<sub>4</sub> 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(Co<sub>0.68</sub>Ni<sub>0.32</sub>)<sub>2</sub>Se<sub>4</sub> as highly-efficient OER electrocatalyst. Paper VI describes three naturally occurring copper selenides (Cu<sub>2</sub>Se, Cu<sub>3</sub>Se<sub>2</sub> and CuSe<sub>2</sub>) as OER electrocatalyst and performed DFT calculation to understand their catalytic activity trend”--Abstract, page iv.</p>"]},{"key":"dc:title","label":"Title","values":["Designing novel multinary transition metal selenides as high-efficiency oxygen evolution reaction electrocatalysts and investigating surface properties"]}]}],"canonical_facts":{"dc:creator":["Cao, Xi"],"dc:description.abstract":["<p>”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 (Ni<sub>0.25</sub>Fe<sub>0.68</sub>Co<sub>0.07</sub>)<sub>3</sub>Se<sub>4</sub> 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 (Co<sub>0.21</sub>Ni<sub>0.25</sub>Cu<sub>0.54</sub>)<sub>3</sub>Se<sub>2</sub> showing a similar crystal structure as its parent compound Cu<sub>3</sub>Se<sub>2</sub>. Paper III introduces the Fe-Co-Cu selenide system investigated through combinatorial electrodeposition, and the optimal quaternary is identified as (Fe<sub>0.48</sub>Co<sub>0.38</sub>Cu<sub>0.14</sub>)Se. Paper IV presents CuCo<sub>2</sub>Se<sub>4</sub> 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(Co<sub>0.68</sub>Ni<sub>0.32</sub>)<sub>2</sub>Se<sub>4</sub> as highly-efficient OER electrocatalyst. Paper VI describes three naturally occurring copper selenides (Cu<sub>2</sub>Se, Cu<sub>3</sub>Se<sub>2</sub> and CuSe<sub>2</sub>) as OER electrocatalyst and performed DFT calculation to understand their catalytic activity trend”--Abstract, page iv.</p>"],"dc:identifier":["https://scholarsmine.mst.edu/doctoral_dissertations/3089"],"dc:subject":["Inorganic Chemistry"],"dc:title":["Designing novel multinary transition metal selenides as high-efficiency oxygen evolution reaction electrocatalysts and investigating surface properties"],"dc:type":["Dissertation - Open Access"],"thesis:degree_name":["Ph. D. in Chemistry"],"thesis:institution_name":["Missouri University of Science and Technology"]},"updated_at":"2026-07-24T03:18:09Z"}