Novel organically linked ZnII hydrogenselenite coordination polymers: synthesis, characterization, and efficient TiO2 photosensitization for enhanced photocatalytic hydrogen production

• Published in: Dalton transactions : an international journal of inorganic chemistry 2023-11, Vol.52 (45), p.16841-16848
• Main Authors: Lunardi, Andressa, Bortolotto, Tanize, Camila Nunes Cechin, Natália de Freitas Daudt, Melina de Azevedo Mello, dos Santos, Sailer S, Cargnelutti, Roberta, Schulz Lang, Ernesto, Tirloni, Bárbara
• Format: Article
• Language: English
• Subjects: Catalytic activity; Chemical synthesis; Clean energy; Coordination polymers; Crystallography; Hydrogen; Hydrogen evolution; Hydrogen production; Photocatalysis; Polymers; Selenium dioxide; Sol-gel processes; Titanium dioxide; Water splitting; Zinc oxide
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d3dt03094f

This study focused on the solvothermal synthesis, characterization, and photocatalytic activities of two novel coordination polymers, namely [Zn(μ-HSeO3)2(bipy)]n (1) and [Zn(μ-HSeO3)2(phen)]n (2). These compounds represent the first organically linked ZnII hydrogenselenite coordination polymers. The synthesis of compounds 1 and 2 involved the addition of 2,2′-bipyridine and 1,10-phenanthroline, respectively, to SeO2 and ZnO in methanol as the solvent. The novel hydrogenselenite compounds were thoroughly characterized using spectroscopic and crystallographic methods. The photocatalytic solids (TiO2-1A and TiO2-2A) were prepared by immobilizing compounds 1–2 onto TiO2 through the sol–gel approach. These photocatalysts were then evaluated for hydrogen evolution via water splitting using a 300 W Hg/Xe lamp as the irradiation source. Among the newly synthesized photocatalytic materials, TiO2-1A demonstrated auspicious photocatalytic performance for hydrogen gas production. Its catalytic activity overcame the observed for the pure solid support TiO2 and Degussa P25 (commercial titania), making compound 1 a particularly attractive TiO2 photosensitizer. Additionally, TiO2-1A exhibited superior photocatalytic activity compared to TiO2-2A. The latter performed better than freshly prepared TiO2, approaching that of Degussa P25. These findings highlight the potential of compound 1 as an effective photosensitizer for TiO2-based photocatalysis, making it a promising candidate for applications in clean energy generation, specifically in hydrogen production by water splitting.