Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Apr 28;64(16):7902-7919.
doi: 10.1021/acs.inorgchem.4c05325. Epub 2025 Apr 16.

Structural Analysis of Selenium Coordination Compounds and Mesoporous TiO2-Based Photocatalysts for Hydrogen Generation

Rodrigo Cervo  1 , Cândida Alíssia Brandl  1 , Tanize Bortolotto  1 , Camila Nunes Cechin  1 , Natália de Freitas Daudt  2 , Bernardo Almeida Iglesias  1 , Ernesto Schulz Lang  1 , Bárbara Tirloni  1 , Roberta Cargnelutti  1
Affiliations

Structural Analysis of Selenium Coordination Compounds and Mesoporous TiO2-Based Photocatalysts for Hydrogen Generation

Rodrigo Cervo et al. Inorg Chem. .

Abstract

This study reports the synthesis of ten coordination compounds (1-10) derived from the ligand bis((3-aminopyridin-2-yl)selanyl)methane (L) and different metal centers (CoII, CuI, CuII, ZnII, and AgI). Single crystals of the complexes were obtained via slow diffusion from overlaid solutions of ligand L and the corresponding metal. Their crystalline structures were determined by single-crystal X-ray diffraction (SCXRD) and further characterized using spectroscopic, spectrometric, and voltammetric techniques. Complexes 1-5, 7, and 10 were evaluated as cocatalysts of mesoporous titanium dioxide (m-TiO2) for photocatalytic hydrogen production via water photolysis under solar light simulation, using triethanolamine (TEOA) as the sacrificial agent. The results showed that complexes 4, 5, 7, and 10 enhanced m-TiO2 photocatalytic activity, achieving hydrogen evolution rates at least four times higher than standard m-TiO2 and P25. Among these, the photocatalyst m-TiO2-7 (7 = [Cu2(μ-SO4)2L2]) exhibited the highest hydrogen production, reaching approximately 7800 μmol/g over a 6-h experiment-nearly 26 times greater than pure m-TiO2 (300 μmol/g). These findings highlight the potential of organoselenium metal complexes for the development of novel photocatalytic materials based on nonprecious metals.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
Molecular structures of some diselanes: (a) 1,2-diphenyldiselane, (b) 1,2-bis(pyridin-2-yl)diselane ((pySe)2), (c) 1,2-bis(3-aminopyridin-2-yl)diselane ((3-apySe)2).
Scheme 1
Scheme 1. Representation of Complexes 1–10, Derived from Ligand L and Their Respective Metal Salts
Figure 2
Figure 2
Structural projections of the complexes: (a) 1, (b) 2, (c) 3, (d) 4, (e) 5. Aromatic hydrogen atoms and CHCl3 molecules have been omitted for clarity.
Figure 3
Figure 3
Structural projection of the polymeric complex 6, with growth along the crystallographic b axis. Some hydrogen atoms have been omitted for clarity. Symmetry operations: (′) = (3/2 – x, 1/2 + y, z) and (″) = (3/2 – x, – 1/2 + y, z).
Figure 4
Figure 4
Structural projections of the complexes (a) 7 and (b) 8. Aromatic hydrogen atoms have been omitted for clarity. Symmetry operations: 7 (′) = (1 – x, 1 – y, 2 – z), 8 (′) = (1 – x, 2 – y, 1 – z).
Figure 5
Figure 5
Structural projections of the cluster complexes (a) 9 and (b) 10. Aromatic hydrogen atoms have been omitted for clarity. Symmetry operation: (′) = (−x, 1 – y, 1 – z).
Figure 6
Figure 6
Comparison of the theoretical and experimental powder diffractograms of complex 8.
Figure 7
Figure 7
Comparison of the FT-IR (left) and Raman (right) spectra of ligand L and diselane (3-apySe)2, with emphasis on the regions of 3000 and 500 cm–1.
Figure 8
Figure 8
Comparison of the Raman spectra of ligand L and complexes 1–10, highlighting the M–N, M–X, and Ag–Se stretching modes. For scaling reasons, the peak for complex 10 has been clipped.
Figure 9
Figure 9
Comparison of the FT-IR spectra of ligand L and complexes 7–10, highlighting the characteristic bands of sulfate and nitrate anions.
Figure 10
Figure 10
1H NMR spectrum (400 MHz, DMSO-d6) of ligand L.
Figure 11
Figure 11
Comparison of coupling constants (in Hz) between ligand L and (3-apySe)2.
Figure 12
Figure 12
13C NMR spectrum (100 MHz, DMSO-d6) of ligand L.
Figure 13
Figure 13
Comparison of 77Se NMR spectra (76 MHz, DMSO-d6) of diselane (3-apySe)2, ligand L, and complex 3.
Figure 14
Figure 14
UV–vis spectra in solution of ligand L and complexes 1–10. Solutions in DMF: L, 1–5; in DMSO: 6–10.
Figure 15
Figure 15
Absorbance spectra of ligand L and complexes 1–10, calculated from diffuse reflectance data.
Figure 16
Figure 16
Results of H2(g) evolution for the photocatalysts m-TiO2-n (n = L, 1–5, 7, or 10), compared to pure m-TiO2 and P25. Sacrificial agent: TEOA (10% in aqueous solution); light source: 300 W Xe/Hg lamp; photocatalyst/solution concentration: 0.5 g/L.
Figure 17
Figure 17
Results of H2(g) evolution in the recycling experiments with the m-TiO2-7 photocatalyst (top) and over 30 h (bottom).
Figure 18
Figure 18
FT-IR (top) and Raman (bottom) spectra of m-TiO2-n photocatalysts.
Figure 19
Figure 19
SEM image (top) and EDS spectrum (bottom) of the m-TiO2-7 photocatalyst.
Figure 20
Figure 20
Elemental mapping of the m-TiO2-7 photocatalyst. The mapping of C was omitted, as it is present in the carbon tape used for sample preparation. Image saturation and lightness have been adjusted for clarity.
Figure 21
Figure 21
Comparison of the voltammograms of ligand L and complexes 4, 5, and 7.
Scheme 2
Scheme 2. Proposed Electron Transfer Mechanism of m-TiO2-7 in the Water Photolysis Process Using TEOA as the Sacrificial Agent
See this image and copyright information in PMC

References

    1. Chen X.; Shen S.; Guo L.; Mao S. S. Semiconductor-based Photocatalytic Hydrogen Generation. Chem. Rev. 2010, 110 (11), 6503–6570. 10.1021/cr1001645. - DOI - PubMed
    2. Wang Q.; Domen K. Particulate Photocatalysts for Light-Driven Water Splitting: Mechanisms, Challenges, and Design Strategies. Chem. Rev. 2020, 120 (2), 919–985. 10.1021/acs.chemrev.9b00201. - DOI - PubMed
    3. Qi K.; Cheng B.; Yu J.; Ho W. A review on TiO2-based Z-scheme photocatalysts. Chin. J. Catal. 2017, 38 (12), 1936–1955. 10.1016/S1872-2067(17)62962-0. - DOI
    4. Maeda K. Photocatalytic water splitting using semiconductor particles: History and recent developments. J. Photochem. Photobiol. C 2011, 12 (4), 237–268. 10.1016/j.jphotochemrev.2011.07.001. - DOI
    5. Mohamadpour F.; Amani A. M. Photocatalytic systems: reactions, mechanism, and applications. RSC Adv. 2024, 14 (29), 20609–20645. 10.1039/D4RA03259D. - DOI - PMC - PubMed
    6. Agbe H.; Nyankson E.; Raza N.; Dodoo-Arhin D.; Chauhan A.; Osei G.; Kumar V.; Kim K.-H. Recent advances in photoinduced catalysis for water splitting and environmental applications. J. Ind. Eng. Chem. 2019, 72, 31–49. 10.1016/j.jiec.2019.01.004. - DOI
    7. Eddy D. R.; Permana M. D.; Sakti L. K.; Sheha G. A. N.; Hidayat S. S.; Takei T.; Kumada N.; Rahayu I. Heterophase Polymorph of TiO2 (Anatase, Rutile, Brookite, TiO2 (B)) for Efficient Photocatalyst: Fabrication and Activity. Nanomaterials 2023, 13, 704. 10.3390/nano13040704. - DOI - PMC - PubMed
    1. Ahluwalia R. K.; Wang X.; Rousseau A.; Kumar R. Fuel economy of hydrogen fuel cell vehicles. J. Power Sources 2004, 130 (1–2), 192–201. 10.1016/j.jpowsour.2003.12.061. - DOI
    2. Fujishima A.; Honda K. Electrochemical Photolysis of Water at a Semiconductor Electrode. Nature 1972, 238, 37–38. 10.1038/238037a0. - DOI - PubMed
    1. Umair M.; Palmisano G.; Sakkaf R. A.; Jitan S. A.; Pintar A.; Žerjav G.; Palmisano L.; Loddo V.; Bellardita M. Pt-Nb2O5-TiO2 based semiconductors for photo-reforming of glucose and fructose aqueous solutions. Appl. Surf. Sci. 2024, 648, 159030. 10.1016/j.apsusc.2023.159030. - DOI
    2. Moinuddin A. A.; Kotkondawar A. V.; Hippargi G.; Anshul A.; Rayalu S. A promising photo-thermal catalytic approach for hydrogen generation from sulphide bearing wastewater. Int. J. Hydrogen Energy 2024, 51, 1151–1160. 10.1016/j.ijhydene.2023.07.178. - DOI
    3. Deka T.; Nair R. G. Recent advancements in surface plasmon resonance and Schottky Junction assisted photocatalytic water splitting of noble metal decorated Titania: A review. Int. J. Hydrogen Energy 2024, 59, 322–342. 10.1016/j.ijhydene.2024.02.002. - DOI
    4. Li H.; Zhu B.; Sun J.; Gong H.; Yu J.; Zhang L. Photocatalytic hydrogen production from seawater by TiO2/RuO2 hybrid nanofiber with enhanced light absorption. J. Colloid Interface Sci. 2024, 654, 1010–1019. 10.1016/j.jcis.2023.10.074. - DOI - PubMed
    5. Rafique M.; Hajra S.; Irshad M.; Usman M.; Imran M.; Assiri M. A.; Ashraf W. M. Hydrogen Production Using TiO2-Based Photocatalysts: A Comprehensive Review. ACS Omega 2023, 8 (29), 25640–25648. 10.1021/acsomega.3c00963. - DOI - PMC - PubMed
    6. Shao C.; Gao D.; Zhang X.; Long H.; Yu H. Optimizing H-adsorption affinity on electron-enriched Pdδ− active sites for efficient photocatalytic H2 evolution. Appl. Surf. Sci. 2025, 680, 161438. 10.1016/j.apsusc.2024.161438. - DOI
    1. Xie A.; Tao Y.-W.; Peng C.; Luo G.-G. A nickel pyridine-selenolate complex for the photocatalytic evolution of hydrogen from aqueous solutions. Inorg. Chem. Commun. 2019, 110, 107598. 10.1016/j.inoche.2019.107598. - DOI
    2. Krief A.; Wemmel T. V.; Redon M.; Dumont W.; Delmotte C. The First Synthesis of Organic Diselenolates: Application to the Synthesis of Diorganyl Diselenides. Angew. Chem., Int. Ed. 1999, 38 (15), 2245–2247. - PubMed
    3. Mugesh G.; Panda A.; Singh H. B.; Punekar N. S.; Butcher R. J. Glutathione Peroxidase-like Antioxidant Activity of Diaryl Diselenides: A Mechanistic Study. J. Am. Chem. Soc. 2001, 123 (5), 839–850. 10.1021/ja994467p. - DOI - PubMed
    4. Ivanova A.; Arsenyan P. Rise of diselenides: Recent advances in the synthesis of heteroarylselenides. Coord. Chem. Rev. 2018, 370, 55–68. 10.1016/j.ccr.2018.05.015. - DOI
    5. Nogueira C. W.; Quinhones E. B.; Jung E. A. C.; Zeni G.; Rocha J. B. T. Anti-inflammatory and antinociceptive activity of diphenyl diselenide. Inflamm. Res. 2003, 52 (2), 56–63. 10.1007/s000110300001. - DOI - PubMed
    6. Giurg M.; Gołąb A.; Suchodolski J.; Kaleta R.; Krasowska A.; Piasecki E.; Piętka-Ottlik M. Reaction of bis[(2-chlorocarbonyl)phenyl] Diselenide with Phenols, Aminophenols, and Other Amines towards Diphenyl Diselenides with Antimicrobial and Antiviral Properties. Molecules 2017, 22 (6), 974. 10.3390/molecules22060974. - DOI - PMC - PubMed
    7. van der Toorn J. C.; Kemperman G.; Sheldon R. A.; Arends I. W. C. E. Diphenyldiselenide-Catalyzed Selective Oxidation of Activated Alcohols with tert-Butyl Hydroperoxide: New Mechanistic Insights. J. Org. Chem. 2009, 74 (8), 3085–3089. 10.1021/jo900059y. - DOI - PubMed
    8. Burger M. E.; Fachinetto R.; Wagner C.; Perottoni J.; Pereira R. P.; Zeni G.; Rocha J. B. T. Effects of diphenyl–diselenide on orofacial dyskinesia model in rats. Brain Res. Bull. 2006, 70 (2), 165–170. 10.1016/j.brainresbull.2006.05.002. - DOI - PubMed
    9. Ban Y.-L.; You L.; Feng K.-W.; Ma F.-C.; Jin X.-L.; Liu Q. Meyer–Schuster-Type Rearrangement of Propargylic Alcohols into α-Selenoenals and -enones with Diselenides. J. Org. Chem. 2021, 86 (7), 5274–5283. 10.1021/acs.joc.1c00167. - DOI - PubMed
    10. Zhang C.; Wang H.; Liang W.; Yang Y.; Cong C.; Wang Y.; Wang S.; Wang X.; Wang D.; Huo D.; Feng H. Diphenyl diselenide protects motor neurons through inhibition of microglia-mediated inflammatory injury in amyotrophic lateral sclerosis. Pharmacol. Res. 2021, 165, 105457. 10.1016/j.phrs.2021.105457. - DOI - PubMed
    11. Kedarnath G.; Jain V. K. Pyridyl and pyrimidyl chalcogen (Se and Te) compounds: A family of multi utility molecules. Coord. Chem. Rev. 2013, 257 (7–8), 1409–1435. 10.1016/j.ccr.2013.01.003. - DOI
    1. Laube J.; Jäger S.; Thöne C. Synthesis and Structural Studies of Pyridine-2-selenolates – Reactions with Electrophilic Phosphorus(III) Compounds and Related Complex Chemistry. Eur. J. Inorg. Chem. 2001, 8, 1983–1992.
    2. Kienitz C. O.; Thöne C.; Jones P. G. Coordination Chemistry of 2,2′-Dipyridyl Diselenide: X-ray Crystal Structures of PySeSePy, [Zn(PySeSePy)Cl2], [(PySeSePy)Hg(C6F5)2], [Mo(SePy)2(CO)3], [W(SePy)2(CO)3], and [Fe(SePy)2(CO)2] (PySeSePy = C5H4NSeSeC5H4N; SePy = [C5H4N(2-Se)-N,Se]). Inorg. Chem. 1996, 35 (13), 3990–3997. 10.1021/ic951454d. - DOI - PubMed
    3. Cargnelutti R.; Schumacher R. F.; Belladona A. L.; Kazmierczak J. C. Coordination chemistry and synthetic approaches of pyridyl-selenium ligands: A decade update. Coord. Chem. Rev. 2021, 426, 213537. 10.1016/j.ccr.2020.213537. - DOI