Pub Date : 2025-03-04DOI: 10.1021/acs.jpcc.4c08669
Keisuke Imaeda, Rin Miyazaki, Sou Ryuzaki, Kosei Ueno
The light confinement capability of optical cavities plays an important role in amplifying the light–matter interactions. To realize high-performance optical cavities, not only a small mode volume but also a high quality (Q) factor is indispensable. Plasmonic nanocavities can squeeze light into deep subwavelength spaces, resulting in ultrasmall mode volumes. However, the Q factors of plasmonic nanocavities are seriously impaired by the intrinsic Ohmic losses, and thus the improvement of the Q factors of plasmonic nanocavities is highly challenging. In this study, we integrate Au nanogap dimers with a distributed Bragg reflector (DBR) to realize the high-Q plasmonic nanocavities. Near-field spectral characterizations reveal that the sharp resonance peak appears near the photonic stopband of the DBR, resulting in a Q factor of ∼75. Ultrafast time-resolved measurements also unveil that the plasmon dephasing time of the Au dimer on the DBR is extended compared to that on a glass substrate. The electromagnetic simulations can qualitatively reproduce the experimental observations and reveal that the high-Q plasmonic nanocavities are achievable due to the synergistic interaction of the Au dimers with the slow light induced at the photonic band edge of the DBR. The integrated system demonstrated in this study exhibits stronger near-field enhancement compared to conventional plasmonic nanocavities on a glass substrate, providing a promising platform for boosting the performance of plasmonic nanocavities in various applications.
{"title":"High-Q Plasmonic Nanocavities Enabled by Integration of Au Nanogap Dimers with a Distributed Bragg Reflector","authors":"Keisuke Imaeda, Rin Miyazaki, Sou Ryuzaki, Kosei Ueno","doi":"10.1021/acs.jpcc.4c08669","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08669","url":null,"abstract":"The light confinement capability of optical cavities plays an important role in amplifying the light–matter interactions. To realize high-performance optical cavities, not only a small mode volume but also a high quality (<i>Q</i>) factor is indispensable. Plasmonic nanocavities can squeeze light into deep subwavelength spaces, resulting in ultrasmall mode volumes. However, the <i>Q</i> factors of plasmonic nanocavities are seriously impaired by the intrinsic Ohmic losses, and thus the improvement of the <i>Q</i> factors of plasmonic nanocavities is highly challenging. In this study, we integrate Au nanogap dimers with a distributed Bragg reflector (DBR) to realize the high-<i>Q</i> plasmonic nanocavities. Near-field spectral characterizations reveal that the sharp resonance peak appears near the photonic stopband of the DBR, resulting in a <i>Q</i> factor of ∼75. Ultrafast time-resolved measurements also unveil that the plasmon dephasing time of the Au dimer on the DBR is extended compared to that on a glass substrate. The electromagnetic simulations can qualitatively reproduce the experimental observations and reveal that the high-<i>Q</i> plasmonic nanocavities are achievable due to the synergistic interaction of the Au dimers with the slow light induced at the photonic band edge of the DBR. The integrated system demonstrated in this study exhibits stronger near-field enhancement compared to conventional plasmonic nanocavities on a glass substrate, providing a promising platform for boosting the performance of plasmonic nanocavities in various applications.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"22 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-04DOI: 10.1021/acs.jpcc.4c08101
Pantea Dara, Mikael Käll
Gold nanostructures have been extensively used as photothermal heat sources in a variety of studies due to their chemical inertness, biocompatibility, and advantageous thermoplasmonic properties. However, gold nanostructures are prone to surface melting and thermal deformation, which, in some cases, limit their applicability. In this study, we investigate micrometer-sized amorphous silicon nanodisk arrays as a stable and biocompatible alternative for the particular application of photothermally induced microbubble formation and generation of strong directional Marangoni flows in water. By using time-modulated continuous-wave laser heating, we show that the induced flows can move microparticles tens of micrometers across a substrate surface. The direction of particle movement can be preselected by utilizing asymmetric pairs of nanodisk arrays as heat sources or dynamically controlled by altering the laser spot position relative to a symmetric pair of arrays. We also demonstrate that average bubble size and particle displacement positively correlate and crucially depend on the laser modulation frequency. These results are discussed in terms of the temporal dynamics of bubble growth following nucleation. Our findings highlight the potential of using silicon nanostructures as substrates for generating strong thermocapillary flows on the micrometer scale, with potential applications in chemical mixing, pumping, particle sorting, and mass transport.
{"title":"Bubble Dynamics and Directional Marangoni Flow Induced by Laser Heating of Silicon Nanodisk Arrays","authors":"Pantea Dara, Mikael Käll","doi":"10.1021/acs.jpcc.4c08101","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08101","url":null,"abstract":"Gold nanostructures have been extensively used as photothermal heat sources in a variety of studies due to their chemical inertness, biocompatibility, and advantageous thermoplasmonic properties. However, gold nanostructures are prone to surface melting and thermal deformation, which, in some cases, limit their applicability. In this study, we investigate micrometer-sized amorphous silicon nanodisk arrays as a stable and biocompatible alternative for the particular application of photothermally induced microbubble formation and generation of strong directional Marangoni flows in water. By using time-modulated continuous-wave laser heating, we show that the induced flows can move microparticles tens of micrometers across a substrate surface. The direction of particle movement can be preselected by utilizing asymmetric pairs of nanodisk arrays as heat sources or dynamically controlled by altering the laser spot position relative to a symmetric pair of arrays. We also demonstrate that average bubble size and particle displacement positively correlate and crucially depend on the laser modulation frequency. These results are discussed in terms of the temporal dynamics of bubble growth following nucleation. Our findings highlight the potential of using silicon nanostructures as substrates for generating strong thermocapillary flows on the micrometer scale, with potential applications in chemical mixing, pumping, particle sorting, and mass transport.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"53 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The reaction mechanism of hydrogenolysis over monomeric MoOx-modified Rh catalysts is investigated by density functional theory-based molecular dynamics simulations. By explicitly treating the surrounding water molecules, the free energy surfaces are constructed for the aqueous-phase hydrogenolysis reaction. Ethylene glycol is employed as a model substrate, and it is shown that the attack of surface hydride-like species on the carbon atom at a position adjacent to the alkoxide ad-species via the SN2 reaction facilitates the cleavage of the C–O bond and it is more efficient than the attack on the carbon atom of alkoxide ad-species. Our study of the SN2 mechanism of the Rh–MoOx catalyst offers insight into the reaction mechanism of hydrogenolysis in the aqueous phase for metal nanoparticles modified with metal-oxide species and the design of selective catalysts for hydrogenolysis and other related reactions of biomass-derived feedstocks.
{"title":"Computational Insight into Selective Hydrogenolysis over Monomeric MoOx-Modified Rh Catalysts in the Aqueous Phase","authors":"Kenshin Takei, Tatsushi Ikeda, Koki Muraoka, Yoshinao Nakagawa, Keiichi Tomishige, Akira Nakayama","doi":"10.1021/acs.jpcc.4c08142","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08142","url":null,"abstract":"The reaction mechanism of hydrogenolysis over monomeric MoO<sub><i>x</i></sub>-modified Rh catalysts is investigated by density functional theory-based molecular dynamics simulations. By explicitly treating the surrounding water molecules, the free energy surfaces are constructed for the aqueous-phase hydrogenolysis reaction. Ethylene glycol is employed as a model substrate, and it is shown that the attack of surface hydride-like species on the carbon atom at a position adjacent to the alkoxide ad-species via the S<sub>N</sub>2 reaction facilitates the cleavage of the C–O bond and it is more efficient than the attack on the carbon atom of alkoxide ad-species. Our study of the S<sub>N</sub>2 mechanism of the Rh–MoO<sub><i>x</i></sub> catalyst offers insight into the reaction mechanism of hydrogenolysis in the aqueous phase for metal nanoparticles modified with metal-oxide species and the design of selective catalysts for hydrogenolysis and other related reactions of biomass-derived feedstocks.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"33 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1021/acs.jpcc.4c07558
Fei Ren, Zongwei Xu
Carbon-related luminescent defects in hexagonal boron nitride (hBN) have the potential to revolutionize sensors and single-photon sources at the atomic scale; however, creating and identifying these defects remain challenging. In this work, we employ analytical potential molecular dynamics (APMD) in conjunction with ab initio molecular dynamics (AIMD) simulations to optimize the ion implantation parameters for creating carbon-related defects in hBN. First, AIMD simulations are conducted to simulate the implantation of low-energy carbon ions into monolayer hBN. Subsequently, APMD simulations based on two types of classic potentials are compared with the results from AIMD simulations, allowing us to determine suitable atomistic potentials. Finally, we predict that carbon atoms can be introduced into monolayer hBN with a 30% probability when the ion energy varies from 40 to 80 eV. Moreover, carbon ion bombardment at 40° can significantly improve the yield of carbon-related color centers. These results can directly guide the generation of vacancy and carbon-related color centers in hBN and even hBN nanotubes for single-photon sources and quantum sensing, and the simulated methods would provide a pathway to understand the formation of carbon-related defects to identify the possible atomic structures.
{"title":"Atomistic Simulations of Carbon Implantation into hBN for Creating Color Centers","authors":"Fei Ren, Zongwei Xu","doi":"10.1021/acs.jpcc.4c07558","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07558","url":null,"abstract":"Carbon-related luminescent defects in hexagonal boron nitride (hBN) have the potential to revolutionize sensors and single-photon sources at the atomic scale; however, creating and identifying these defects remain challenging. In this work, we employ analytical potential molecular dynamics (APMD) in conjunction with <i>ab initio</i> molecular dynamics (AIMD) simulations to optimize the ion implantation parameters for creating carbon-related defects in hBN. First, AIMD simulations are conducted to simulate the implantation of low-energy carbon ions into monolayer hBN. Subsequently, APMD simulations based on two types of classic potentials are compared with the results from AIMD simulations, allowing us to determine suitable atomistic potentials. Finally, we predict that carbon atoms can be introduced into monolayer hBN with a 30% probability when the ion energy varies from 40 to 80 eV. Moreover, carbon ion bombardment at 40° can significantly improve the yield of carbon-related color centers. These results can directly guide the generation of vacancy and carbon-related color centers in hBN and even hBN nanotubes for single-photon sources and quantum sensing, and the simulated methods would provide a pathway to understand the formation of carbon-related defects to identify the possible atomic structures.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"1 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1021/acs.jpcc.4c07837
Michelle Sykes Akerman, Baran Eren
Surface impurities can have a significant effect on the initial adsorption of adsorbates to a substrate. When the adsorbate is a hydrogen-bonding molecule, such as methanol, its ability to form hydrogen-bonded structures and networks on the surface may be affected as well. Here, polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) is used to explore how the surface properties and temperature affect the growth and structure of crystalline multilayer ices of methanol. Differences in the PM-IRRAS spectra for methanol films grown on bare Cu(111) and oxygen-precovered Cu(111) (Cu(111)/O) at two different adsorption temperatures (120 and 140 K) reveal that different structures of methanol ices are obtained under each set of conditions. The methanol-Cu(111) interaction is relatively weak. Methanol molecules form long-range hydrogen-bonded structures on Cu(111) at both 120 and 140 K. The preadsorption of oxygen on Cu(111) increases the interaction of methanol with the surface; at 120 K, the methanol molecules form hydrogen bonds with the surface, while at 140 K, the methanol molecules are dissociated into methoxy and water. In both cases, the formation of long-range hydrogen-bonded structures is hindered, and the subsequently adsorbed layers of methanol are relatively disordered. The most ordered methanol ices are grown on Cu(111) at 140 K, while the most disordered methanol ices are grown on Cu(111)/O at 120 K.
{"title":"Effect of Temperature and Surface Properties on the Growth of Crystalline Multilayers of Methanol on Copper","authors":"Michelle Sykes Akerman, Baran Eren","doi":"10.1021/acs.jpcc.4c07837","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07837","url":null,"abstract":"Surface impurities can have a significant effect on the initial adsorption of adsorbates to a substrate. When the adsorbate is a hydrogen-bonding molecule, such as methanol, its ability to form hydrogen-bonded structures and networks on the surface may be affected as well. Here, polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) is used to explore how the surface properties and temperature affect the growth and structure of crystalline multilayer ices of methanol. Differences in the PM-IRRAS spectra for methanol films grown on bare Cu(111) and oxygen-precovered Cu(111) (Cu(111)/O) at two different adsorption temperatures (120 and 140 K) reveal that different structures of methanol ices are obtained under each set of conditions. The methanol-Cu(111) interaction is relatively weak. Methanol molecules form long-range hydrogen-bonded structures on Cu(111) at both 120 and 140 K. The preadsorption of oxygen on Cu(111) increases the interaction of methanol with the surface; at 120 K, the methanol molecules form hydrogen bonds with the surface, while at 140 K, the methanol molecules are dissociated into methoxy and water. In both cases, the formation of long-range hydrogen-bonded structures is hindered, and the subsequently adsorbed layers of methanol are relatively disordered. The most ordered methanol ices are grown on Cu(111) at 140 K, while the most disordered methanol ices are grown on Cu(111)/O at 120 K.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"18 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1021/acs.jpcc.5c00088
Qian Ai, Lalith Krishna Samanth Bonagiri, Amir Farokh Payam, Narayana R. Aluru, Yingjie Zhang
Three-dimensional atomic force microscopy (3D-AFM) has been a powerful tool to probe the atomic-scale structure of solid–liquid interfaces. As a nanoprobe moves along the 3D volume of interfacial liquid, the probe–sample interaction force is sensed and mapped, providing information on not only the solid morphology, but also the liquid density distribution. To date, 3D-AFM force maps of a diverse set of solid–liquid interfaces have been recorded, revealing remarkable force oscillations that are typically attributed to solvation layers or electrical double layers. However, despite the high resolution down to the subangstrom level, quantitative interpretation of the 3D force maps has been an outstanding challenge. Here we review the technical details of 3D-AFM and the existing approaches for quantitative data interpretation. Based on evidence in recent literature, we conclude that the perturbation-induced AFM force paradoxically represents the intrinsic, unperturbed liquid density profile. We will further discuss how the oscillatory force profiles can be attributed to the probe-modulation of the liquid configurational entropy and how the quantitative, atomic-scale liquid density distribution can be derived from the force maps.
{"title":"Toward Quantitative Interpretation of 3D Atomic Force Microscopy at Solid–Liquid Interfaces","authors":"Qian Ai, Lalith Krishna Samanth Bonagiri, Amir Farokh Payam, Narayana R. Aluru, Yingjie Zhang","doi":"10.1021/acs.jpcc.5c00088","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c00088","url":null,"abstract":"Three-dimensional atomic force microscopy (3D-AFM) has been a powerful tool to probe the atomic-scale structure of solid–liquid interfaces. As a nanoprobe moves along the 3D volume of interfacial liquid, the probe–sample interaction force is sensed and mapped, providing information on not only the solid morphology, but also the liquid density distribution. To date, 3D-AFM force maps of a diverse set of solid–liquid interfaces have been recorded, revealing remarkable force oscillations that are typically attributed to solvation layers or electrical double layers. However, despite the high resolution down to the subangstrom level, quantitative interpretation of the 3D force maps has been an outstanding challenge. Here we review the technical details of 3D-AFM and the existing approaches for quantitative data interpretation. Based on evidence in recent literature, we conclude that the perturbation-induced AFM force paradoxically represents the intrinsic, unperturbed liquid density profile. We will further discuss how the oscillatory force profiles can be attributed to the probe-modulation of the liquid configurational entropy and how the quantitative, atomic-scale liquid density distribution can be derived from the force maps.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"56 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143532774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1021/acs.jpcc.4c08674
Evangelos Smith, Trenton J. Wolter, Robert J. Twieg, Nicholas L. Abbott, Manos Mavrikakis
Recent studies have revealed that metal adatom clusters exhibit distinct catalytic properties compared to conventionally modeled extended facets. Here, we used periodic density functional theory (DFT) to investigate differences in O2 activation between two-dimensional clusters of Pd atoms supported on Au(111) (adclusters) and embedded within Au(111). We analyzed the barriers for O2* dissociation and desorption on Pd clusters ranging in size from one to nine Pd atoms in a (4 × 4) surface unit cell. Our findings revealed that, while O2* dissociation barriers between adclusters and embedded clusters are similar, adclusters exhibit significantly higher desorption barriers than embedded clusters by between 0.3 and 0.7 eV. This suggests that Au surfaces with Pd adclusters have enhanced selectivities for O2* dissociation over desorption, which may yield faster rates for processes limited by O2 activation. Additionally, we evaluated the stability of Pd–Au surfaces under vacuum and in the presence of O2*, calculating the temperature required for Pd adatom formation from Pd atoms embedded in Au(111). Our predictions show that adatom formation is unlikely as the competing desorption or dissociation of O2* occurs at lower temperatures for all considered cluster sizes. These findings highlight the role of surface roughness in catalytic processes on Pd–Au bimetallic surfaces.
{"title":"First-Principles Study of O2 Activation over Pd Adclusters and Embedded Clusters in Pd–Au Bimetallic Surfaces","authors":"Evangelos Smith, Trenton J. Wolter, Robert J. Twieg, Nicholas L. Abbott, Manos Mavrikakis","doi":"10.1021/acs.jpcc.4c08674","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c08674","url":null,"abstract":"Recent studies have revealed that metal adatom clusters exhibit distinct catalytic properties compared to conventionally modeled extended facets. Here, we used periodic density functional theory (DFT) to investigate differences in O<sub>2</sub> activation between two-dimensional clusters of Pd atoms supported on Au(111) (adclusters) and embedded within Au(111). We analyzed the barriers for O<sub>2</sub>* dissociation and desorption on Pd clusters ranging in size from one to nine Pd atoms in a (4 × 4) surface unit cell. Our findings revealed that, while O<sub>2</sub>* dissociation barriers between adclusters and embedded clusters are similar, adclusters exhibit significantly higher desorption barriers than embedded clusters by between 0.3 and 0.7 eV. This suggests that Au surfaces with Pd adclusters have enhanced selectivities for O<sub>2</sub>* dissociation over desorption, which may yield faster rates for processes limited by O<sub>2</sub> activation. Additionally, we evaluated the stability of Pd–Au surfaces under vacuum and in the presence of O<sub>2</sub>*, calculating the temperature required for Pd adatom formation from Pd atoms embedded in Au(111). Our predictions show that adatom formation is unlikely as the competing desorption or dissociation of O<sub>2</sub>* occurs at lower temperatures for all considered cluster sizes. These findings highlight the role of surface roughness in catalytic processes on Pd–Au bimetallic surfaces.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"18 3 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143532785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1021/acs.jpcc.5c00468
Sihang Liu, Zamaan Mukadam, Angus Pedersen, Jesús Barrio, Joseph Parker, Helen Tyrrell, Sarah J. Haigh, Maria Magdalena Titirici, Ifan E. L. Stephens, Georg Kastlunger
Nitrogen-doped carbon-based single-atom catalysts offer unique and tunable active sites to catalyze a wide spectrum of electrochemical processes. Despite recent progress on single-atom electrocatalysis, their potential application to upgrade biomass-derived chemicals has rarely been investigated. Herein, we carried out density-functional-theory-based screening of metal–nitrogen–carbon (MNC) single-atom catalysts for electrocatalytic furfural reduction. Using furfural’s adsorption strength as a descriptor, we identified CrNC to promote furfuryl alcohol production in contrast to other single atom motifs which are only selective to hydrofuroin. Its higher selectivity toward furfuryl alcohol can be attributed to the enhanced adsorption strength of furfural via chemisorption of the carbonyl group and its overall enhanced oxygen binding strength. We then synthesized the single-atom motifs via their incorporation in a highly porous nitrogen-doped carbon synthesized through an ionothermal templating process. In agreement with our predictions, CrNC was able to produce furfuryl alcohol with Faradaic efficiency of ca. 18%, while Co, Fe, and NiNC motifs selectively produce hydrofuroin, with limited Faradaic efficiencies to furfuryl alcohol <3%. Our work showcases a proof-of-concept for the design and optimization of single-atom catalysts to bridge the selectivity toward outer- and inner-sphere electron-transfer-based products from biomass-derived chemicals.
{"title":"Bridging Outer- and Inner-Sphere Electrosynthesis from Biomass-Derived Furfural Using Single Atom Catalysts","authors":"Sihang Liu, Zamaan Mukadam, Angus Pedersen, Jesús Barrio, Joseph Parker, Helen Tyrrell, Sarah J. Haigh, Maria Magdalena Titirici, Ifan E. L. Stephens, Georg Kastlunger","doi":"10.1021/acs.jpcc.5c00468","DOIUrl":"https://doi.org/10.1021/acs.jpcc.5c00468","url":null,"abstract":"Nitrogen-doped carbon-based single-atom catalysts offer unique and tunable active sites to catalyze a wide spectrum of electrochemical processes. Despite recent progress on single-atom electrocatalysis, their potential application to upgrade biomass-derived chemicals has rarely been investigated. Herein, we carried out density-functional-theory-based screening of metal–nitrogen–carbon (MNC) single-atom catalysts for electrocatalytic furfural reduction. Using furfural’s adsorption strength as a descriptor, we identified CrNC to promote furfuryl alcohol production in contrast to other single atom motifs which are only selective to hydrofuroin. Its higher selectivity toward furfuryl alcohol can be attributed to the enhanced adsorption strength of furfural via chemisorption of the carbonyl group and its overall enhanced oxygen binding strength. We then synthesized the single-atom motifs via their incorporation in a highly porous nitrogen-doped carbon synthesized through an ionothermal templating process. In agreement with our predictions, CrNC was able to produce furfuryl alcohol with Faradaic efficiency of ca. 18%, while Co, Fe, and NiNC motifs selectively produce hydrofuroin, with limited Faradaic efficiencies to furfuryl alcohol <3%. Our work showcases a proof-of-concept for the design and optimization of single-atom catalysts to bridge the selectivity toward outer- and inner-sphere electron-transfer-based products from biomass-derived chemicals.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"29 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143532777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1021/acs.jpcc.4c07916
Jinpeng Lv, Hancheng Feng, Ruoxin Bai
The high transmissivity, high thermal conductivity, and radiation hardness of diamond make it ideal for use in harsh radiative environments. Herein, the influence of 90 keV O+ and H+ as well as 1 MeV electron irradiation with fluence up to 1 × 1017 ions/cm2 on bulk diamond crystals are systematically investigated, in combination with morphological, structural, and optoelectronic characterization. The results show that H+ irradiation increases the electron concentration of diamond, while O+ and electrons show adverse effects. H+ irradiation turns the diamond from colorless to brownish, while O+ irradiation results in a blackness appearance. Although electron irradiation drastically decreases the transmissivity in the near-infrared region (1–2.5 μm) from 33% to only 2%, it still remains visually transparent. Interestingly, irradiation remarkably enhances the room temperature 575, 637, and 738 nm related luminescence, due to the formation of the NV and SiV defects facilitated by irradiation-created vacancies. Compared to H+ and O+ irradiation, electron irradiation creates the strongest defect luminescence (intensified by nearly 9 times) while undergoing moderate radiation damage, which could be employed as an efficient method to tune defect luminescence in diamonds for quantum sensing.
{"title":"Improvement in Fluorescence Intensity of Color Centers in Diamond by High-Fluence Irradiation","authors":"Jinpeng Lv, Hancheng Feng, Ruoxin Bai","doi":"10.1021/acs.jpcc.4c07916","DOIUrl":"https://doi.org/10.1021/acs.jpcc.4c07916","url":null,"abstract":"The high transmissivity, high thermal conductivity, and radiation hardness of diamond make it ideal for use in harsh radiative environments. Herein, the influence of 90 keV O<sup>+</sup> and H<sup>+</sup> as well as 1 MeV electron irradiation with fluence up to 1 × 10<sup>17</sup> ions/cm<sup>2</sup> on bulk diamond crystals are systematically investigated, in combination with morphological, structural, and optoelectronic characterization. The results show that H<sup>+</sup> irradiation increases the electron concentration of diamond, while O<sup>+</sup> and electrons show adverse effects. H<sup>+</sup> irradiation turns the diamond from colorless to brownish, while O<sup>+</sup> irradiation results in a blackness appearance. Although electron irradiation drastically decreases the transmissivity in the near-infrared region (1–2.5 μm) from 33% to only 2%, it still remains visually transparent. Interestingly, irradiation remarkably enhances the room temperature 575, 637, and 738 nm related luminescence, due to the formation of the NV and SiV defects facilitated by irradiation-created vacancies. Compared to H<sup>+</sup> and O<sup>+</sup> irradiation, electron irradiation creates the strongest defect luminescence (intensified by nearly 9 times) while undergoing moderate radiation damage, which could be employed as an efficient method to tune defect luminescence in diamonds for quantum sensing.","PeriodicalId":61,"journal":{"name":"The Journal of Physical Chemistry C","volume":"23 1","pages":""},"PeriodicalIF":4.126,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-03DOI: 10.1021/acs.jpcc.4c08058
Katharina Helmbrecht, Axel Groß
Batteries using multivalent charge carriers present a promising alternative to traditional Li-ion technology, offering the potential for higher energy densities and often relying on more abundant elements. However, their ion mobility within the electrolyte and cathode is generally lower than that of monovalent carriers due to stronger electrostatic interactions, heightening the need for materials that can provide high ion mobility. NASICON materials are known for their high ion mobility with monovalent carriers such as lithium and sodium and are widely used as solid electrolytes. In this computational study, we investigate two NASICON materials in particular with respect to their ion mobility for the bivalent charge carrier calcium, focusing on how the transition metal’s atomic size in the NASICON material influences the height of the migration barrier and the properties of the materials as a solid electrolyte or electrode material. We found both materials to be good candidates for solid electrolytes with sufficiently low ion migration barriers. We confirm that the triangular faces of the octahedra along the reaction path whose size scales with the radii of the transition metal atoms act as the bottlenecks for migration.
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