Dinitrosyl iron complexes (DNICs) acting as catalyst for photocatalytic hydrogen evolution reaction (HER)

Abstract

Electrochemical study of {Fe(NO) 2 } 10 DNIC [(2-AMP)Fe(NO) 2 ] (1) (2-AMP = 2-aminomethylpyridine) in CH 3 CN/Na 2 SO 4 aqueous solution (1 M) revealing reversible one-electron redox couples implicated that DNIC 1 may facilitate versatile chemical reactions associated with two-electron HER (hydrogen evolution reaction) processes. The three-component photocatalytic HER system is composed of MeOH-H 2 O solution (1:1 volume ratio, pH = 11.0) of molecular catalyst DNIC 1 (1.6 μM), photosensitizer fluorescein (Fl) (1.5 mM) and sacrificial electron donor triethylamine (0.36 M) was developed. The reductive quenching rate (R 1 ) (electron transfer from Et 3 N to Fl) and the oxidative quenching rate (R 2 ) (electron transfer from [Fl] À to DNIC 1) were calculated as 2.11 Â 10 7 s À1 and 3.984 Â 10 4 s À1 , respectively. The faster electron transfer from [Fl] À to DNIC 1, compared to the electron-transfer rate (R 3 ) from [DNIC 1] À to H 2 O, rationalized the accumulation of the transientstable [DNIC 1] À , degrading to [DNIC 1] À -transformed photocatalytic active particles (Fe 3 O 4 [major]). The three-component photocatalytic system composed of MeOH-H 2 O solution of the isolated particles (2 mg), Fl (1.5 mM), andEt 3 N (0.36 M) was also employed for photocatalytic HER reaching TON 13456 μmol H2 /g catalyst , TOF 2691 hr À1 μmol H2 /g catalyst and the apparent quantum yield 3.71% under radiation (480 nm). That is, for the photocatalytic HER device constructed via a combination of DNIC 1, Fluorescein, and triethylamine, both the homogeneous catalytic HER triggered by {Fe(NO) 2 } 10reduced [DNIC 1] À and the heterogeneous catalytic HER promoted by [DNIC 1] À -transformed particles operated concomitantly to drive this photocatalytic HER.

One-Pot Photosynthesis of Cubic Fe@Fe3O4 Core–Shell Nanoparticle Well-Dispersed in N-Doping Carbonaceous Polymer Using a Molecular Dinitrosyl Iron Precursor

“…Inspired by the photochemistry of DNIC [(NO) 2 Fe­(μ-SR) 2 Fe­(NO) 2 ] and electrolytic activation of 1 - PMDTA for deposition of amorphous iron/iron oxide particles on the graphite electrode, − herein, {Fe­(NO) 2 } 10 DNIC coordinated with another α-diimine ligand N 3 MDA, [(N 3 MDA)­Fe­(NO) 2 ] ( 1 - N 3 MDA ), was explored as a molecular precursor for the preparation of nanoscale zerovalent iron (NZVI). Through combination with photosensitizer Eosin Y and sacrificial reductant TEA, of importance, photolysis of DNIC 1 - N 3 MDA results in the one-pot synthesis of a cubic Fe@Fe 3 O 4 core–shell nanoparticle well-dispersed in N-doping carbonaceous polymer.…”

Potential Use of Waste in Electrocatalysis Using Foundry Sand as Electrocatalyst for the Hydrogen Evolution Reaction

“…6), it was possible to determine the mechanism of hydrogen evolution. 36 As a multi-step process, the first one occurs when protons are discharged/ adsorbed on the surface of the electrode (Eq. 2), and then two paths Being the most important kinetic parameter used in studying any electrocatalyst for HER, as lower the Tafel slope, the more efficient the catalyst.…”

Advanced Microwave Strategies Facilitate Structural Engineering for Efficient Electrocatalysis

“…This reaction proceeds through a two-proton-twoelectron pathway (2H + (aq) + 2e À !H 2 (g)). [90] The HER constitutes a multifaceted sequence of reactions encompassing adsorption (Volmer step), reduction, and desorption (Heyrovsky or Tafel step) processes. These processes exhibit a pronounced dependency on the chemical and electronic attributes of the catalyst.…”

“…Electrochemical hydrogen evolution reaction involves the generation of hydrogen through the electrochemical splitting of water molecules induced by an externally applied voltage on catalysts. This reaction proceeds through a two‐proton‐two‐electron pathway (2H + (aq)+2e − →H 2 (g)) [90] . The HER constitutes a multifaceted sequence of reactions encompassing adsorption (Volmer step), reduction, and desorption (Heyrovsky or Tafel step) processes.…”