Synthesis and photocatalytic evaluation of first nickel dioxo-haloselenate complexes immobilized on mesoporous TiO2 for enhanced solar-driven hydrogen production
Cândida Alíssia Brandl, Andressa Lunardi, Camila Nunes Cechin, Tanize Bortolotto, Natália de Freitas Daudt, Robert Alan Burrow, Bernardo Almeida Iglesias, Artur Luís Hennemann, Koiti Araki, Ulrich Abram, Ernesto Schulz Lang, Bárbara Tirloni
{"title":"Synthesis and photocatalytic evaluation of first nickel dioxo-haloselenate complexes immobilized on mesoporous TiO2 for enhanced solar-driven hydrogen production","authors":"Cândida Alíssia Brandl, Andressa Lunardi, Camila Nunes Cechin, Tanize Bortolotto, Natália de Freitas Daudt, Robert Alan Burrow, Bernardo Almeida Iglesias, Artur Luís Hennemann, Koiti Araki, Ulrich Abram, Ernesto Schulz Lang, Bárbara Tirloni","doi":"10.1039/d5qi00317b","DOIUrl":null,"url":null,"abstract":"[NiBr(SeO<small><sub>2</sub></small>Br)(bipy)<small><sub>2</sub></small>] (<strong>1</strong>), [NiBr(SeO<small><sub>2</sub></small>Br)(phen)<small><sub>2</sub></small>] (<strong>2</strong>), and [NiCl(SeO<small><sub>2</sub></small>Cl)(bipy)<small><sub>2</sub></small>] (<strong>3</strong>), represent the first nickel complexes incorporating dioxo-haloselenate anions. These complexes were selected due to their unique structural features, and light absorption properties, which make them promising candidates for photocatalytic applications. The compounds were immobilized onto mesoporous TiO<small><sub>2</sub></small> (m-TiO<small><sub>2</sub></small>), resulting in photocatalysts <strong>1</strong>@m-TiO<small><sub>2</sub></small>, <strong>2</strong>@m-TiO<small><sub>2</sub></small>, and <strong>3</strong>@m-TiO<small><sub>2</sub></small>, which were evaluated for solar-driven water splitting to produce hydrogen. Electrochemical analyses revealed suitable HOMO–LUMO energy levels for visible-light activation, and X-ray photoelectron spectroscopy confirmed changes in surface composition upon immobilization. Among the photocatalysts, <strong>2</strong>@m-TiO<small><sub>2</sub></small> exhibited the highest H<small><sub>2</sub></small> production, achieving 927 μmol g<small><sup>−1</sup></small> in 6 hours, outperforming both <strong>1</strong>@m-TiO<small><sub>2</sub></small> (803 μmol g<small><sup>−1</sup></small>) and <strong>3</strong>@m-TiO<small><sub>2</sub></small> (810 μmol g<small><sup>−1</sup></small>), as well as reference materials m-TiO<small><sub>2</sub></small> and Degussa P25. Moreover, complex <strong>1</strong> demonstrated intrinsic electrochemical activity for H<small><sub>2</sub></small> evolution in acidic media. Recycling experiments showed the stability of <strong>2</strong>@m-TiO<small><sub>2</sub></small> over three cycles, confirming its robustness. These findings not only demonstrate the effective cocatalytic role of complexes <strong>1–3</strong> in enhancing H<small><sub>2</sub></small> generation but also shed light on interfacial photo-induced processes <em>via</em> HOMO–LUMO evaluation and XPS analysis. This study introduces the first example of nickel-based dioxo-haloselenate complexes as cocatalysts, opening new avenues for the development of sustainable hydrogen-evolving materials.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"606 1","pages":""},"PeriodicalIF":6.1000,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganic Chemistry Frontiers","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1039/d5qi00317b","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
Abstract
[NiBr(SeO2Br)(bipy)2] (1), [NiBr(SeO2Br)(phen)2] (2), and [NiCl(SeO2Cl)(bipy)2] (3), represent the first nickel complexes incorporating dioxo-haloselenate anions. These complexes were selected due to their unique structural features, and light absorption properties, which make them promising candidates for photocatalytic applications. The compounds were immobilized onto mesoporous TiO2 (m-TiO2), resulting in photocatalysts 1@m-TiO2, 2@m-TiO2, and 3@m-TiO2, which were evaluated for solar-driven water splitting to produce hydrogen. Electrochemical analyses revealed suitable HOMO–LUMO energy levels for visible-light activation, and X-ray photoelectron spectroscopy confirmed changes in surface composition upon immobilization. Among the photocatalysts, 2@m-TiO2 exhibited the highest H2 production, achieving 927 μmol g−1 in 6 hours, outperforming both 1@m-TiO2 (803 μmol g−1) and 3@m-TiO2 (810 μmol g−1), as well as reference materials m-TiO2 and Degussa P25. Moreover, complex 1 demonstrated intrinsic electrochemical activity for H2 evolution in acidic media. Recycling experiments showed the stability of 2@m-TiO2 over three cycles, confirming its robustness. These findings not only demonstrate the effective cocatalytic role of complexes 1–3 in enhancing H2 generation but also shed light on interfacial photo-induced processes via HOMO–LUMO evaluation and XPS analysis. This study introduces the first example of nickel-based dioxo-haloselenate complexes as cocatalysts, opening new avenues for the development of sustainable hydrogen-evolving materials.