Oxidation Temperature-Dependent Electrochemical Doping of WO3 Deposited via Atomic Layer Deposition DOI
Alexandria R. C. Bredar, Hannah R. M. Margavio, Carrie L. Donley

et al.

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 9, 2024

Silicon-based photoelectrochemical devices show promise for the performance of light-driven CO2 reduction but suffer from instability under conditions relevant to reduction. Coating silicon electrodes with thin layers metal oxides has shown passivate unstable surfaces, and many different can be deposited on using various techniques. In this study, we investigate fundamental WO3-coated photoelectrodes, which were generated by oxidation W-metal films via atomic layer deposition both degenerately doped (nSi+) low-doped (pSi) silicon. Two temperatures investigated (400 600 °C), it was found that monoclinic phase WO3 predominates at more grain boundaries are present in °C film. From X-ray photoelectron spectroscopy, stoichiometry 1:3 W:O, low electron energy loss experiments indicate band gaps 3.0 3.1 eV 400 films, respectively. Cyclic voltammetry showed transfer kinetics increased after continued redox cycling, particularly material produced °C. spectra suggest observed increase electrode conductivity is due formation oxygen vacancies Electrochemical impedance spectroscopy indicated charge transport through impacted formed during Photoelectrochemical studies pSi/WO3 highly variable, only producing a photocurrent photovoltage some samples. Our best sample, °C, 180 mV, lower than what previously been reported (500 mV). We hypothesize variability arose roughened WSiOx interface film preparation. shows as oxide coating silicon, our results high-quality between Si vital performance.

Language: Английский

Photoelectrocatalytic reduction of CO2 to formate using immobilized molecular manganese catalysts on oxidized porous silicon DOI
Young Hyun Hong, Xiaofan Jia, Eleanor Stewart-Jones

et al.

Chem, Journal Year: 2025, Volume and Issue: unknown, P. 102462 - 102462

Published: March 1, 2025

Language: Английский

Citations

2
Photoelectrochemical Proton-Coupled Electron Transfer of TiO2 Thin Films on Silicon DOI
Hannah S. Nedzbala,

Dalaney Westbroek,

Hannah R. M. Margavio

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10559 - 10572

Published: April 2, 2024

TiO2 thin films are often used as protective layers on semiconductors for applications in photovoltaics, molecule–semiconductor hybrid photoelectrodes, and more. Experiments reported here show that silicon electrochemically photoelectrochemically reduced buffered acetonitrile at potentials relevant to photoelectrocatalysis of CO2 reduction, N2 H2 evolution. On both n-type Si irradiated p-type Si, reduction is proton-coupled with a 1e–:1H+ stoichiometry, demonstrated by the Nernstian dependence Ti4+/3+ E1/2 buffer pKa. were conducted without illumination, photovoltage ∼0.6 V was observed across 20 orders magnitude proton activity. The 4 nm almost stoichiometrically under mild conditions. catalytically transfer protons electrons hydrogen atom acceptors, based cyclic voltammogram, bulk electrolysis, other mechanistic evidence. TiO2/Si thus has potential generate high-energy H carriers. Characterization after reveals restructuring formation islands, rendering potentially poor choice protecting or catalyst supports reducing protic Overall, this work demonstrates atomic layer deposition photoelectrodes undergo chemical morphological changes upon application only modestly negative RHE these media. While results should serve cautionary tale researchers aiming immobilize molecular monolayers "protective" metal oxides, robust electron reactivity introduces opportunities photoelectrochemical generation reactive charge-carrying mediators.

Language: Английский

Citations

12
Design Strategies for Coupling CO2 Reduction Molecular Electrocatalysts to Silicon Photocathodes DOI Creative Commons
Simran S. Saund, Melissa K. Gish, Jeremiah C. Choate

et al.

ACS Materials Au, Journal Year: 2025, Volume and Issue: unknown

Published: April 14, 2025

Language: Английский

Citations

0
Tricarbonyl rhenium(i) complexes with 8-hydroxyquinolines: structural, chemical, antibacterial, and anticancer characteristics DOI Creative Commons
Krzysztof Łyczko, Anna Pogorzelska, Urszula Częścik

et al.

RSC Advances, Journal Year: 2024, Volume and Issue: 14(25), P. 18080 - 18092

Published: Jan. 1, 2024

Twelve tricarbonyl Re( i ) complexes with bidentate 8-hydroxyquinolinato and monodentate diazole ligands were synthesized, characterized by scXRD, IR, NMR, UV-Vis methods, checked for antibacterial anticancer activity.

Language: Английский

Citations

3
Methyl Termination of p-Type Silicon Enables Selective Photoelectrochemical CO2 Reduction by a Molecular Ruthenium Catalyst DOI
Gabriella P. Bein, Madison A. Stewart, Eric A. Assaf

et al.

ACS Energy Letters, Journal Year: 2024, Volume and Issue: 9(4), P. 1777 - 1785

Published: March 27, 2024

Methyl-terminated p-type silicon photoelectrodes selectively drive CO2 reduction by a homogeneous [Ru(tpy)(Mebim-py)(NCCH3)]2+ catalyst (tpy = 2,2′:6′,2″-terpyridine, Mebim-py 1-methylbenzimidazol-2-ylidene-3-(2′-pyridine)). A 460 mV photovoltage is quantified for the photoelectrode. Under 1 sun illumination, this system achieves Faradaic efficiency of 87% CO at −1.7 V vs Fc+/0, matching reports same metallic electrodes operating −2.1 V. When 5% water introduced, CH3-terminated Si photoelectrode remains stable, selectivity retained, and current density increases. Methyl termination suppresses competitive hydrogen evolution observed H-terminated photoelectrodes, which under conditions produce ca. 60% 8% H2 have unstable performance. These results establish that semiconductor can power molecular without itself. p-Si allows to kinetically outcompete proton reduction, revealing an important design principle selective fuel formation.

Language: Английский

Citations

2
Kinetic Isotope Effects and the Mechanism of CO2 Insertion into the Metal-Hydride Bond of fac-(bpy)Re(CO)3H DOI

Mariam Barakat,

Sarah Elhajj,

Riyad Yazji

et al.

Inorganic Chemistry, Journal Year: 2024, Volume and Issue: 63(26), P. 12133 - 12145

Published: June 20, 2024

The 1,2-insertion reaction of CO2 into metal–hydride bonds d6-octahedral complexes to give κ1-O-metal-formate products is the key step in various reduction schemes and as a result has attracted extensive mechanistic investigations. For many octahedral catalysts, insertion follows an associative mechanism which interacts directly with coordinated hydride ligand instead more classical dissociative that opens empty coordination site bind substrate metal prior migration step. To better understand mechanism, we conducted systematic quantum chemical investigation on between fac-(bpy)Re(CO)3H (1–Re–H; bpy = 2,2′-bipyridine) starting gas phase then moving THF other solvents increased dielectric constants. Detailed analyses potential energy surfaces (PESs) intrinsic coordinates (IRCs) reveal enabled all media by initial stage making 3c-2e bond carbon metal-hydride most consistent organometallic bridging Re–H–CO2 species. Once bent anchored bond, proceeds rotation motion via cyclic transition state TS2 interchanges Re–O–CHO coordination. combined stages provide asynchronous–concerted pathway for Gibbs free surface highest point. Consideration rate-determining TS gives activation barriers, inverse KIEs, substituent effects, solvent effects agree experimental data available this system. An important new insight revealed results not transfer been assumed some studies. In fact, loose vibration can be identified first solution (TS1) does involve Re–H stretching vibrational mode. Accordingly, imaginary frequency TS1 insensitive deuteration, therefore, leads no significant KIE.

Language: Английский

Citations

2
Direct Detection of Key Intermediates during the Product Release in Rhenium Bipyridine-Catalyzed CO2 Reduction Reaction DOI Creative Commons
Samir Chattopadhyay, Mun Hon Cheah, Reiner Lomoth

et al.

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(21), P. 16324 - 16334

Published: Oct. 22, 2024

Rhenium bipyridine tricarbonyl complexes, fac-[Re(bpy)(CO)3X]n+, are highly effective in selectively converting CO2 to CO under electrochemical and photochemical conditions. Despite numerous mechanistic studies aimed at understanding its reduction reaction (CO2RR) pathway, the intermediates further into catalytic cycle have escaped detection, steps leading product release remained elusive. In this study, employing stopped-flow mixing coupled with time-resolved infrared spectroscopy, we observed, for first time, reduced Re-tetracarbonyl species, [Re(bpy)(CO)4]0, a half-life of approximately 55 ms acetonitrile solvent. This intermediate is proposed be common both CO2RR. Furthermore, directly observed (CO) from intermediate. Additionally, detected accumulation [Re(bpy)(CO)3(CH3CN)]+ as byproduct following release, significant side conditions limited supply reducing equivalents mirroring The process could unambiguously attributed an electron transfer-catalyzed ligand substitution involving [Re(bpy)(CO)4]0 by simultaneous real-time detection all involved species. We believe that significantly impacts CO2RR efficiency class catalysts or during electrocatalysis mild overpotentials.

Language: Английский

Citations

2
Quinoline- rhenium(I) tricarbonyl complexes: synthesis, spectral characterization and antiproliferative activity on T-cell lymphoma DOI
Martina Piškor,

Ivan Ćorić,

Berislav Perić

et al.

Journal of Inorganic Biochemistry, Journal Year: 2024, Volume and Issue: 262, P. 112770 - 112770

Published: Oct. 30, 2024

Language: Английский

Citations

2
Recent Advances in Immobilizing and Benchmarking Molecular Catalysts for Artificial Photosynthesis DOI
Lei Wang,

Mengjiao Shao,

Zhu‐Lin Xie

et al.

Langmuir, Journal Year: 2024, Volume and Issue: 40(46), P. 24195 - 24215

Published: Nov. 4, 2024

Transition metal complexes have been widely used as catalysts or chromophores in artificial photosynthesis. Traditionally, they are employed homogeneous settings. Despite their functional versatility and structural tunability, broad industrial applications of these impeded by the limitations catalysis such poor catalyst recyclability, solvent constraints (mostly organic solvents), durability. Over past few decades, researchers developed various methods for molecular heterogenization to overcome limitations. In this review, we summarize recent developments strategies, with a focus on describing process effects catalytic performances. Alongside in-depth discussion review aims provide concise overview key metrics associated heterogenized systems. We hope will aid who new research field gaining better understanding.

Language: Английский

Citations

2
Linear Free Energy Relationships Associated with Hydride Transfer From [(6,6′-R2-bpy)Re(CO)3H]: A Cautionary Tale in Identifying Hydrogen Bonding Effects in the Secondary Coordination Sphere DOI
Matthew R. Elsby, Abhishek Kumar,

L.M. Daniels

et al.

Inorganic Chemistry, Journal Year: 2024, Volume and Issue: 63(41), P. 19396 - 19407

Published: Sept. 30, 2024

Six rhenium hydride complexes, [(6,6'-R

Citations

1