Andrew Bocarsly | Princeton University (original) (raw)
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Papers by Andrew Bocarsly
Journal of the American Chemical Society, Jan 9, 2014
Polycrystalline CuRhO2 is investigated as a photocathode for the splitting of water under visible... more Polycrystalline CuRhO2 is investigated as a photocathode for the splitting of water under visible irradiation. The band edge positions of this material straddle the water oxidation and reduction redox potentials. Thus, photogenerated conduction band electrons are sufficiently energetic to reduce water, while the associated valence band holes are energetically able to oxidize water to O2. Under visible illumination, H2 production is observed with ~0.2 V underpotential in an air-saturated solution. In contrast, H2 production in an Ar-saturated solution was found to be unstable. This instability is associated with the reduction of the semiconductor forming Cu(s). However, in the presence of air or O2, bulk Cu(s) was not detected, implying that CuRhO2 is self-healing when air is present. This property allows for the stable formation of H2 with ca. 80% Faradaic efficiency.
Dalton Transactions, 2019
A mechanistic analysis showing the critical importance of an intramolecular hydrogen bond for imp... more A mechanistic analysis showing the critical importance of an intramolecular hydrogen bond for improved insight and understanding in CO2 electroreduction.
Chemistry of Materials, 2018
Chemistry of Materials, 2018
Dalton transactions (Cambridge, England : 2003), Jan 19, 2018
Manganese(i) tricarbonyl complexes such as [Mn(bpy)(CO)3L] (L = Br, or CN) are known to be electr... more Manganese(i) tricarbonyl complexes such as [Mn(bpy)(CO)3L] (L = Br, or CN) are known to be electrocatalysts for CO2 reduction to CO. However, due to their rapid photodegradation under UV and visible light, these monomeric manganese complexes have not been considered as photocatalysts for CO2 reduction without the use of a photosensitizer. In this paper, we report a cyanide-bridged di-manganese complex, {[Mn(bpy)(CO)3]2(μ-CN)}ClO4, which is both electrocatalytic and photochemically active for CO2 reduction to CO. Compared to the [Mn(bpy)(CO)3CN] electrocatalyst, our CN-bridged binuclear complex is a more efficient electrocatalyst for CO2 reduction using H2O as a proton source. In addition, we report a photochemical CO2 reduction to CO using the dimanganese complex under 395 nm irradiation.
The Journal of Physical Chemistry C, 2018
In a search for improved photocathode materials for fuel-producing photoelectrochemical cells, qu... more In a search for improved photocathode materials for fuel-producing photoelectrochemical cells, quaternary Ag x Cu 1-x Ga y In 1-y S 2 (0 ≤ x ≤ 1.0, 0 ≤ y ≤ 1.0) p-type, chalcopyrite semiconductors (SCIGS) were prepared and tested for photochemical hydrogen evolution. The study reported here is based on the preparation of bulk phases of the quaternary system. In contrast to thin film studies of this system, this approach enables enhanced control of the materials chemical, structural and electronic properties. Compared to ternary CIGS electrode materials the quaternary SCIGS materials provide improved photoelectrochemical and electrocatalytic properties. The quaternary system allows for adjustment of the band structures and photocatalytic abilities to a finer degree than is possible in the Ag x Cu 1-x GaS 2 or Ag x Cu 1-x InS 2 ternaries, and several of the quaternary Ag x Cu 1-x Ga y In 1-y S 2 compositions are found to show better
Le Journal de Physique Colloques, 1983
Solar Hydrogen and Nanotechnology V, 2010
![Research paper thumbnail of Exploring the effect of axial ligand substitution (X = Br, NCS, CN) on the photodecomposition and electrochemical activity of [MnX(N–C)(CO)3] complexes](https://attachments.academia-assets.com/117654015/thumbnails/1.jpg)
](Dalton Transactions, 2015
Four new Mn(i)-NHC compounds are tested for light stability and catalytic efficiency for reducing... more Four new Mn(i)-NHC compounds are tested for light stability and catalytic efficiency for reducing CO2 to CO.
The Journal of Physical Chemistry A, 2004
The dynamics of relaxation following photoinduced metal-to-metal charge-transfer (MMCT) processes... more The dynamics of relaxation following photoinduced metal-to-metal charge-transfer (MMCT) processes of the trinuclear mixed-valence complexes [(NC) 5 Ru II-CN-Pt IV (NH 3) 4-NC-Ru II (CN) 5 ] 4and [(NC) 5 Fe II-CN-Pt IV (NH 3) 4-NC-Fe II (CN) 5 ] 4were investigated with femtosecond pump-probe spectroscopy. Relaxation dynamics following photoinduced M(II) f Pt(IV) MMCT varied with solvent and the identity of the M(II) centers. The back-electron-transfer (BET) time scale of [(NC) 5 Ru II-CN-Pt IV (NH 3) 4-NC-Ru II (CN) 5 ] 4ranged from 476 (23 fs in water to 1110 (288 fs in a water/DMSO mixture with mole fraction DMSO of 0.1. The time scale of vibrational relaxation in the ground state ranged from 1.5 to 2.7 ps. Electron-transfer and groundstate vibrational relaxation dynamics of [(NC) 5 Fe II-CN-Pt IV (NH 3) 4-NC-Fe II (CN) 5 ] 4were convolved, with relaxation to ground and product electronic states occurring within 3.5 ps. The electron-transfer dynamics of both complexes are significantly slower than the solvation dynamics of water or DMSO. The solvent dependence of the BET time scale of [(NC) 5 Ru II-CN-Pt IV (NH 3) 4-NC-Ru II (CN) 5 ] 4is attributed to solvent-induced movement of the ground-state potential energy surface and the resulting changes in the driving force for BET. These effects enable systematic control over both the quantum yield of photodissociation and the dynamics of relaxation following photoinduced MMCT.
Journal of Materials Chemistry, 2009
Journal of The Electrochemical Society, 2003
The Journal of Chemical Physics, 1999
We calculate both the exponent and the prefactor in the nucleation rate of a periodically driven ... more We calculate both the exponent and the prefactor in the nucleation rate of a periodically driven system. Nucleation dynamics is described by the Fokker–Planck equation for the probability distribution of the nuclei over their size. This distribution is found using the concept of the most probable (optimal) nucleation path. The results apply in a broad range of driving force amplitudes, from weak to moderately strong forces where the nucleation rate is changed exponentially strongly, and also in the broad range of the driving frequencies, from low-frequency driving, where the system follows the force adiabatically, to high-frequency nonadiabatic driving. For strong driving forces, the time dependence of the nucleation rate changes from strongly nonsinusoidal to a weak with the increasing frequency of driving. The response of the nucleation rate to the driving force is described in terms of logarithmic susceptibility (LS), which can be obtained from the optimal nucleation path in the ...
![Research paper thumbnail of Redox Reactivity as the Controlling Element in Coordination Polymer Stereochemistry: Redox-Switched Growth Mechanism in the [FeII−CN−PtIV]n System](https://attachments.academia-assets.com/117654013/thumbnails/1.jpg)
](Inorganic Chemistry, 1998
Inorganic Chemistry, 1980
X does not generate radical intermediates. On the basis of these results, we conclude that photoi... more X does not generate radical intermediates. On the basis of these results, we conclude that photoinduced geometric isomerization reactions of cisand trans-CpM-(CO),(PPh,)X occur via intramolecular rearrangements of the excited-state complexes. There are apparently three chemically distinct excited-state deactivation pathways available to these complexes, i.e., intramolecular isomerization, dissociation of carbon monoxide, and dissociation of PPh3. However, knowledge concerning the electronic structures of the ground-state complexes and the character of the low-lying excited states and their conversion pathways to other electronic states is severely lacking. Hopefully, relationships between electronic structure and photochemical reactivity patterns for these complexes will be elucidated in the near future.
ChemSusChem, 2013
As an approach to combat the increasing emissions of carbon dioxide in the last 50 years, the seq... more As an approach to combat the increasing emissions of carbon dioxide in the last 50 years, the sequestration of carbon dioxide gas in ionic liquids has become an attractive research area. Ionic liquids can be made that possess incredibly high molar absorption and specificity characteristics for carbon dioxide. Their high carbon dioxide solubility and specificity combined with their high inherent electrical conductivity also creates an ideal medium for the electrochemical reduction of carbon dioxide. Herein, a lesser studied ionic liquid, 1‐ethyl‐3‐methylimidazolium trifluoroacetate, was used as both an effective carbon dioxide capture material and subsequently as an electrochemical matrix with water for the direct reduction of carbon dioxide into formate at indium, tin, and lead electrodes in good yield (ca. 3 mg h−1 cm−2).
Journal of the American Chemical Society, Jan 9, 2014
Polycrystalline CuRhO2 is investigated as a photocathode for the splitting of water under visible... more Polycrystalline CuRhO2 is investigated as a photocathode for the splitting of water under visible irradiation. The band edge positions of this material straddle the water oxidation and reduction redox potentials. Thus, photogenerated conduction band electrons are sufficiently energetic to reduce water, while the associated valence band holes are energetically able to oxidize water to O2. Under visible illumination, H2 production is observed with ~0.2 V underpotential in an air-saturated solution. In contrast, H2 production in an Ar-saturated solution was found to be unstable. This instability is associated with the reduction of the semiconductor forming Cu(s). However, in the presence of air or O2, bulk Cu(s) was not detected, implying that CuRhO2 is self-healing when air is present. This property allows for the stable formation of H2 with ca. 80% Faradaic efficiency.
Dalton Transactions, 2019
A mechanistic analysis showing the critical importance of an intramolecular hydrogen bond for imp... more A mechanistic analysis showing the critical importance of an intramolecular hydrogen bond for improved insight and understanding in CO2 electroreduction.
Chemistry of Materials, 2018
Chemistry of Materials, 2018
Dalton transactions (Cambridge, England : 2003), Jan 19, 2018
Manganese(i) tricarbonyl complexes such as [Mn(bpy)(CO)3L] (L = Br, or CN) are known to be electr... more Manganese(i) tricarbonyl complexes such as [Mn(bpy)(CO)3L] (L = Br, or CN) are known to be electrocatalysts for CO2 reduction to CO. However, due to their rapid photodegradation under UV and visible light, these monomeric manganese complexes have not been considered as photocatalysts for CO2 reduction without the use of a photosensitizer. In this paper, we report a cyanide-bridged di-manganese complex, {[Mn(bpy)(CO)3]2(μ-CN)}ClO4, which is both electrocatalytic and photochemically active for CO2 reduction to CO. Compared to the [Mn(bpy)(CO)3CN] electrocatalyst, our CN-bridged binuclear complex is a more efficient electrocatalyst for CO2 reduction using H2O as a proton source. In addition, we report a photochemical CO2 reduction to CO using the dimanganese complex under 395 nm irradiation.
The Journal of Physical Chemistry C, 2018
In a search for improved photocathode materials for fuel-producing photoelectrochemical cells, qu... more In a search for improved photocathode materials for fuel-producing photoelectrochemical cells, quaternary Ag x Cu 1-x Ga y In 1-y S 2 (0 ≤ x ≤ 1.0, 0 ≤ y ≤ 1.0) p-type, chalcopyrite semiconductors (SCIGS) were prepared and tested for photochemical hydrogen evolution. The study reported here is based on the preparation of bulk phases of the quaternary system. In contrast to thin film studies of this system, this approach enables enhanced control of the materials chemical, structural and electronic properties. Compared to ternary CIGS electrode materials the quaternary SCIGS materials provide improved photoelectrochemical and electrocatalytic properties. The quaternary system allows for adjustment of the band structures and photocatalytic abilities to a finer degree than is possible in the Ag x Cu 1-x GaS 2 or Ag x Cu 1-x InS 2 ternaries, and several of the quaternary Ag x Cu 1-x Ga y In 1-y S 2 compositions are found to show better
Le Journal de Physique Colloques, 1983
Solar Hydrogen and Nanotechnology V, 2010
Dalton Transactions, 2015
Four new Mn(i)-NHC compounds are tested for light stability and catalytic efficiency for reducing... more Four new Mn(i)-NHC compounds are tested for light stability and catalytic efficiency for reducing CO2 to CO.
The Journal of Physical Chemistry A, 2004
The dynamics of relaxation following photoinduced metal-to-metal charge-transfer (MMCT) processes... more The dynamics of relaxation following photoinduced metal-to-metal charge-transfer (MMCT) processes of the trinuclear mixed-valence complexes [(NC) 5 Ru II-CN-Pt IV (NH 3) 4-NC-Ru II (CN) 5 ] 4and [(NC) 5 Fe II-CN-Pt IV (NH 3) 4-NC-Fe II (CN) 5 ] 4were investigated with femtosecond pump-probe spectroscopy. Relaxation dynamics following photoinduced M(II) f Pt(IV) MMCT varied with solvent and the identity of the M(II) centers. The back-electron-transfer (BET) time scale of [(NC) 5 Ru II-CN-Pt IV (NH 3) 4-NC-Ru II (CN) 5 ] 4ranged from 476 (23 fs in water to 1110 (288 fs in a water/DMSO mixture with mole fraction DMSO of 0.1. The time scale of vibrational relaxation in the ground state ranged from 1.5 to 2.7 ps. Electron-transfer and groundstate vibrational relaxation dynamics of [(NC) 5 Fe II-CN-Pt IV (NH 3) 4-NC-Fe II (CN) 5 ] 4were convolved, with relaxation to ground and product electronic states occurring within 3.5 ps. The electron-transfer dynamics of both complexes are significantly slower than the solvation dynamics of water or DMSO. The solvent dependence of the BET time scale of [(NC) 5 Ru II-CN-Pt IV (NH 3) 4-NC-Ru II (CN) 5 ] 4is attributed to solvent-induced movement of the ground-state potential energy surface and the resulting changes in the driving force for BET. These effects enable systematic control over both the quantum yield of photodissociation and the dynamics of relaxation following photoinduced MMCT.
Journal of Materials Chemistry, 2009
Journal of The Electrochemical Society, 2003
The Journal of Chemical Physics, 1999
We calculate both the exponent and the prefactor in the nucleation rate of a periodically driven ... more We calculate both the exponent and the prefactor in the nucleation rate of a periodically driven system. Nucleation dynamics is described by the Fokker–Planck equation for the probability distribution of the nuclei over their size. This distribution is found using the concept of the most probable (optimal) nucleation path. The results apply in a broad range of driving force amplitudes, from weak to moderately strong forces where the nucleation rate is changed exponentially strongly, and also in the broad range of the driving frequencies, from low-frequency driving, where the system follows the force adiabatically, to high-frequency nonadiabatic driving. For strong driving forces, the time dependence of the nucleation rate changes from strongly nonsinusoidal to a weak with the increasing frequency of driving. The response of the nucleation rate to the driving force is described in terms of logarithmic susceptibility (LS), which can be obtained from the optimal nucleation path in the ...
Inorganic Chemistry, 1998
Inorganic Chemistry, 1980
X does not generate radical intermediates. On the basis of these results, we conclude that photoi... more X does not generate radical intermediates. On the basis of these results, we conclude that photoinduced geometric isomerization reactions of cisand trans-CpM-(CO),(PPh,)X occur via intramolecular rearrangements of the excited-state complexes. There are apparently three chemically distinct excited-state deactivation pathways available to these complexes, i.e., intramolecular isomerization, dissociation of carbon monoxide, and dissociation of PPh3. However, knowledge concerning the electronic structures of the ground-state complexes and the character of the low-lying excited states and their conversion pathways to other electronic states is severely lacking. Hopefully, relationships between electronic structure and photochemical reactivity patterns for these complexes will be elucidated in the near future.
ChemSusChem, 2013
As an approach to combat the increasing emissions of carbon dioxide in the last 50 years, the seq... more As an approach to combat the increasing emissions of carbon dioxide in the last 50 years, the sequestration of carbon dioxide gas in ionic liquids has become an attractive research area. Ionic liquids can be made that possess incredibly high molar absorption and specificity characteristics for carbon dioxide. Their high carbon dioxide solubility and specificity combined with their high inherent electrical conductivity also creates an ideal medium for the electrochemical reduction of carbon dioxide. Herein, a lesser studied ionic liquid, 1‐ethyl‐3‐methylimidazolium trifluoroacetate, was used as both an effective carbon dioxide capture material and subsequently as an electrochemical matrix with water for the direct reduction of carbon dioxide into formate at indium, tin, and lead electrodes in good yield (ca. 3 mg h−1 cm−2).