Sandra Elizabeth Saji - Academia.edu (original) (raw)

Papers by Sandra Elizabeth Saji

ACS applied electronic materials, Oct 3, 2022

ACS Applied Electronic Materials

Advanced materials and technologies, Jun 17, 2023

A scalable growth of atomically‐thin 2D transition metal dichalcogenides (TMDs) with defect‐free ... more A scalable growth of atomically‐thin 2D transition metal dichalcogenides (TMDs) with defect‐free large‐area surfaces is crucial for developing high‐performing optoelectronic devices. Herein, a method to grow large‐area, high‐quality MoSe2 monolayers, MoSe2–WSe2, and WSe2–MoSe2 lateral heterostructures using molten salt‐based chemical vapor deposition (CVD) is systematically reported. First, effects of isolated inorganic (sodium chloride (NaCl) and sodium nitrate (NaNO3)), organic (Perylene–3,4,9,10–tetracarboxylic acid tetrapotassium salt (PTAS), mixed inorganic (NaCl/NaNO3), and hybrid organic–inorganic (PTAS/NaCl/NaNO3) salt catalysts on the CVD growth and optoelectronic quality of MoSe2 monolayers and their lateral heterostructures with WSe2 in MoSe2–WSe2 and WSe2–MoSe2 assemblies are investigated. Results show that molten salt catalysts (NaCl/NaNO3 and PTAS/NaCl/NaNO3) support high‐quality, large‐area growth of MoSe2 monolayers with low defect density. The mixed inorganic salt supports growth of MoSe2–WSe2 lateral heterostructures but not their counterpart. Meanwhile, WSe2–MoSe2 lateral heterostructures are optimally grown, supported by the hybrid organic–inorganic salt. These results are ascribed to the difference in the associated kinetic and thermodynamic mechanisms for the growths of MoSe2 and WSe2 as starting materials. Last, it is confirmed that optoelectronic quality of realized heterostructures and monolayers is improved compared to their mechanically exfoliated counterparts. The obtained high‐quality, large‐area 2D TMD heterostructures can be useful for various optoelectronic applications.

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Plasmonic materials exhibit tremendous potential to drive chemical conversions by photo-mediated ... more Plasmonic materials exhibit tremendous potential to drive chemical conversions by photo-mediated redox catalysis.[1–5] A remarkable leverage of these materials over other catalysts is the ability to facilitate reactions efficaciously under milder conditions. Plasmonic materials are especially important due to their superior light focusing ability from free-space wavelength to sub-wavelength range.[6] The characteristic feature of a typical plasmonic photocatalyst is illustrated in the Figure 1. In these materials, essentially the collective electronic excitations generated at metal or metal-like surfaces (plasmons) induced by light sources drive catalytic conversions with exceptional activity.[7] Recent development of efficient plasmonic materials for photo redox catalysis has resulted in unprecedented advancement in important applications such as water splitting, CO2 reduction, organic transformations, dye degradation, environment purification, cancer therapies, etc.[8–11] In parti...

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Crystals, 2021

As a potential magnetic super adsorbent in wastewater treatment, Fe3O4 has been researched intens... more As a potential magnetic super adsorbent in wastewater treatment, Fe3O4 has been researched intensively up to date. However, its key problem of poor comprehensive magnetic properties is still challenging. In this work, an effective solution to this problem has been developed by a one-step carbothermal synthesis of Fe3O4 crystals, which are merited with pure-stoichiometry (FeO-phase free), high crystallinity, small-size (~10 nm), strong magnetism and sensitive magnetic response. The unveiled saturation magnetization of Fe3O4 nanoparticles reaches as high as 90.32 emu·g−1, and the fastest magnetic response time is as short as only 5 s. Such magnetic Fe3O4 super adsorbents exhibit outstanding performance when applied as an adsorbent for wastewater treatment. They can quickly and effectively adsorb methylene blue with an adsorption capacity of 62.5 mg·g−1, which is much higher than that of Fe3O4 adsorbents prepared by other methods reported in the literature. Importantly, this capacity i...

Applied Catalysis B: Environmental, 2021

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Small, 2021

Crystallographic facets in a crystal carry interior properties and proffer rich functionalities i... more Crystallographic facets in a crystal carry interior properties and proffer rich functionalities in a wide range of application areas. However, rational prediction, on-demand customization, and accurate synthesis of facets and facet junctions of a crystal are enormously desirable but still challenging. Herein, a framework of machine learning (ML)-aided crystal facet design with ionic liquid controllable synthesis is developed and then demonstrated with the star-material anatase TiO2 . Aided by employing ML to acquire surface energies from facet junction datasource, the relationships between surface energy and growth conditions based on the Langmuir adsorption isotherm are unveiled, enabling to develop controllable facet synthetic strategies. These strategies are successfully verified after applied for synthesizing TiO2 crystals with custom crystal facets and facet junctions under tuning ionic liquid [bmim][BF4 ] experimental conditions. Therefore, this innovative framework integrates data-intensive rational design and experimental controllable synthesis to develop and customize crystallographic facets and facet junctions. This proves the feasibility of an intelligent chemistry future to accelerate the discovery of facet-governed functional material candidates.

Advanced Energy Materials, 2020

Plasmonic materials with their unique properties, such as light‐excitable resonant oscillation of... more Plasmonic materials with their unique properties, such as light‐excitable resonant oscillation of conduction electrons, strong local electric field, and energetic hot charges (electrons/holes) etc., have overcome the limitations of traditional photoredox catalysts. They are especially important due to their superior light focusing ability, from free‐space wavelengths to the sub‐wavelength range. Although noble metal plasmonic enhancement has been recognized as one of the most important strategies in photocatalysis, the high cost and limited spectral range absorption of noble metals remain the biggest challenges for their practical application, which has led to a gradual shift in the focus on the abundant and less expensive non‐noble metal plasmonics. Recently, various non‐noble plasmonic materials such as non‐noble metals (Cu, Al, Ni and Bi), metal oxides and chalcogenides (WO3‐x, MoO3‐x, NiO, MNbO3, where M = Ca, Sr or Ba; Fe2O3, SrTiO3, In2O3, Cu2‐xS and Bi2Se3), nitrides (TiN, ZrN, HfN and WN) have emerged as efficient photocatalysts. Herein, the door to the relatively new and exciting world of noble metal‐free plasmonic materials and their promising applicability in solar‐energy driven photo‐redox catalysis such as water splitting, CO2 reduction, nitrogen reduction, organic transformations and environment remediation is opened. Their synthesis methods and a plethora of characterization techniques are also systematically exhibited.

Cell Reports Physical Science, 2021

Highlights Twisted MoS 2 /WS 2 demonstrates a giant ILE energy amplitude ILE amplitudes rely on t... more Highlights Twisted MoS 2 /WS 2 demonstrates a giant ILE energy amplitude ILE amplitudes rely on the stacking nature and chemical elements of heterobilayers Minimal interlayer distance with twist commands wide ILE amplitudes

Advanced Materials, 2021

To improve the performance of metallic catalysts, alloying provides an efficient methodology to d... more To improve the performance of metallic catalysts, alloying provides an efficient methodology to design state‐of‐the‐art materials. As emerging functional materials, rare‐earth metal compounds can integrate the unique orbital structure and catalytic behavior of rare earth elements into metallic materials. Such rare‐earth containing alloy catalysts proffer an opportunity to tailor electronic properties, tune charged carrier transport, and synergize surface reactivity, which are expected to significantly improve the performance and stability of catalysis. Despite its significance, there are only few reviews on rare earth containing alloys or related topics. This review summarizes the composition, synthesis, and applications of rare earth containing alloys in the field of catalysis. Subsequent to comprehensively summarizing and constructively discussing the existing work, the challenges and possibilities of future research on rare‐earth metal compound materials are evaluated.

Applied Catalysis B: Environmental, 2021

Chemical Research in Chinese Universities, 2020

The introduction of plasmons is an important method to solve the insufficient utilization of the ... more The introduction of plasmons is an important method to solve the insufficient utilization of the full spectrum of solar energy by semiconductor catalysts. However, semiconductor catalysts combined with traditional noble metal plasmons(Au, Ag) can only extend the absorption spectrum to partially visible light. In order to further improve the photoenergy absorption efficiency of catalysts, they need to be able to effectively utilize near-infrared light, which has become a new research direction. Recent studies have shown that traditional noble metal plasmons can absorb a part of NIR through special morphology, size control and material composite. At the same time, gratifying achievements have been made in the application of plasmonic semiconductors with broad spectrum absorption in catalysis. This article reviews the principles of generating and regulating plasmonic effects in different catalytic systems. The applications of plasmon absorption of near-infrared light in energy conversion and environmental remediation have also been presented.

Applied Catalysis B: Environmental, 2021

The sluggish catalytic reactivity on the surface of most semiconductors is a common obstacle in d... more The sluggish catalytic reactivity on the surface of most semiconductors is a common obstacle in developing photo-electrochemical (PEC) electrodes. Loading cocatalysts becomes a plausible scenario but remains challenging in the integration with semiconductors due to the complicated interfacial issues. This work introduces an feasible strategy of activating surface reactivity, alternative to cocatalysis, in cooperating with semiconductor photoactivity to boost PEC performance. We apply an ionized argon plasma technology on three-dimensional (3D) nanoporous BiVO 4 (BVO) to controllably generate surface oxygen vacancies, which enable surface activation favoring charge separation and transfer towards water oxidation reaction (WOR). A remarkable photocurrent density of 4.32 mA cm −2 is achieved at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5 G illumination, which is a record among the reported single BVO photoanodes and even surpasses the performances of most cocatalyst-assisted ones. This study provides an alternative solution to sluggish catalytic kinetics on semiconductor photoelectrodes, thus paving a novel avenue to modulate cooperation with photoactivity in PEC technology.

RSC Advances, 2020

Dynamic simulation is employed to reveal the mechanism of electrochemical nanofabrication of nano... more Dynamic simulation is employed to reveal the mechanism of electrochemical nanofabrication of nanoscale probes for atomic resolution imaging in STM.

ACS applied electronic materials, Oct 3, 2022

ACS Applied Electronic Materials

Advanced materials and technologies, Jun 17, 2023

A scalable growth of atomically‐thin 2D transition metal dichalcogenides (TMDs) with defect‐free ... more A scalable growth of atomically‐thin 2D transition metal dichalcogenides (TMDs) with defect‐free large‐area surfaces is crucial for developing high‐performing optoelectronic devices. Herein, a method to grow large‐area, high‐quality MoSe2 monolayers, MoSe2–WSe2, and WSe2–MoSe2 lateral heterostructures using molten salt‐based chemical vapor deposition (CVD) is systematically reported. First, effects of isolated inorganic (sodium chloride (NaCl) and sodium nitrate (NaNO3)), organic (Perylene–3,4,9,10–tetracarboxylic acid tetrapotassium salt (PTAS), mixed inorganic (NaCl/NaNO3), and hybrid organic–inorganic (PTAS/NaCl/NaNO3) salt catalysts on the CVD growth and optoelectronic quality of MoSe2 monolayers and their lateral heterostructures with WSe2 in MoSe2–WSe2 and WSe2–MoSe2 assemblies are investigated. Results show that molten salt catalysts (NaCl/NaNO3 and PTAS/NaCl/NaNO3) support high‐quality, large‐area growth of MoSe2 monolayers with low defect density. The mixed inorganic salt supports growth of MoSe2–WSe2 lateral heterostructures but not their counterpart. Meanwhile, WSe2–MoSe2 lateral heterostructures are optimally grown, supported by the hybrid organic–inorganic salt. These results are ascribed to the difference in the associated kinetic and thermodynamic mechanisms for the growths of MoSe2 and WSe2 as starting materials. Last, it is confirmed that optoelectronic quality of realized heterostructures and monolayers is improved compared to their mechanically exfoliated counterparts. The obtained high‐quality, large‐area 2D TMD heterostructures can be useful for various optoelectronic applications.

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Plasmonic materials exhibit tremendous potential to drive chemical conversions by photo-mediated ... more Plasmonic materials exhibit tremendous potential to drive chemical conversions by photo-mediated redox catalysis.[1–5] A remarkable leverage of these materials over other catalysts is the ability to facilitate reactions efficaciously under milder conditions. Plasmonic materials are especially important due to their superior light focusing ability from free-space wavelength to sub-wavelength range.[6] The characteristic feature of a typical plasmonic photocatalyst is illustrated in the Figure 1. In these materials, essentially the collective electronic excitations generated at metal or metal-like surfaces (plasmons) induced by light sources drive catalytic conversions with exceptional activity.[7] Recent development of efficient plasmonic materials for photo redox catalysis has resulted in unprecedented advancement in important applications such as water splitting, CO2 reduction, organic transformations, dye degradation, environment purification, cancer therapies, etc.[8–11] In parti...

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Crystals, 2021

As a potential magnetic super adsorbent in wastewater treatment, Fe3O4 has been researched intens... more As a potential magnetic super adsorbent in wastewater treatment, Fe3O4 has been researched intensively up to date. However, its key problem of poor comprehensive magnetic properties is still challenging. In this work, an effective solution to this problem has been developed by a one-step carbothermal synthesis of Fe3O4 crystals, which are merited with pure-stoichiometry (FeO-phase free), high crystallinity, small-size (~10 nm), strong magnetism and sensitive magnetic response. The unveiled saturation magnetization of Fe3O4 nanoparticles reaches as high as 90.32 emu·g−1, and the fastest magnetic response time is as short as only 5 s. Such magnetic Fe3O4 super adsorbents exhibit outstanding performance when applied as an adsorbent for wastewater treatment. They can quickly and effectively adsorb methylene blue with an adsorption capacity of 62.5 mg·g−1, which is much higher than that of Fe3O4 adsorbents prepared by other methods reported in the literature. Importantly, this capacity i...

Applied Catalysis B: Environmental, 2021

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Atomic and Nano Scale Materials for Advanced Energy Conversion, 2021

Small, 2021

Crystallographic facets in a crystal carry interior properties and proffer rich functionalities i... more Crystallographic facets in a crystal carry interior properties and proffer rich functionalities in a wide range of application areas. However, rational prediction, on-demand customization, and accurate synthesis of facets and facet junctions of a crystal are enormously desirable but still challenging. Herein, a framework of machine learning (ML)-aided crystal facet design with ionic liquid controllable synthesis is developed and then demonstrated with the star-material anatase TiO2 . Aided by employing ML to acquire surface energies from facet junction datasource, the relationships between surface energy and growth conditions based on the Langmuir adsorption isotherm are unveiled, enabling to develop controllable facet synthetic strategies. These strategies are successfully verified after applied for synthesizing TiO2 crystals with custom crystal facets and facet junctions under tuning ionic liquid [bmim][BF4 ] experimental conditions. Therefore, this innovative framework integrates data-intensive rational design and experimental controllable synthesis to develop and customize crystallographic facets and facet junctions. This proves the feasibility of an intelligent chemistry future to accelerate the discovery of facet-governed functional material candidates.

Advanced Energy Materials, 2020

Plasmonic materials with their unique properties, such as light‐excitable resonant oscillation of... more Plasmonic materials with their unique properties, such as light‐excitable resonant oscillation of conduction electrons, strong local electric field, and energetic hot charges (electrons/holes) etc., have overcome the limitations of traditional photoredox catalysts. They are especially important due to their superior light focusing ability, from free‐space wavelengths to the sub‐wavelength range. Although noble metal plasmonic enhancement has been recognized as one of the most important strategies in photocatalysis, the high cost and limited spectral range absorption of noble metals remain the biggest challenges for their practical application, which has led to a gradual shift in the focus on the abundant and less expensive non‐noble metal plasmonics. Recently, various non‐noble plasmonic materials such as non‐noble metals (Cu, Al, Ni and Bi), metal oxides and chalcogenides (WO3‐x, MoO3‐x, NiO, MNbO3, where M = Ca, Sr or Ba; Fe2O3, SrTiO3, In2O3, Cu2‐xS and Bi2Se3), nitrides (TiN, ZrN, HfN and WN) have emerged as efficient photocatalysts. Herein, the door to the relatively new and exciting world of noble metal‐free plasmonic materials and their promising applicability in solar‐energy driven photo‐redox catalysis such as water splitting, CO2 reduction, nitrogen reduction, organic transformations and environment remediation is opened. Their synthesis methods and a plethora of characterization techniques are also systematically exhibited.

Cell Reports Physical Science, 2021

Highlights Twisted MoS 2 /WS 2 demonstrates a giant ILE energy amplitude ILE amplitudes rely on t... more Highlights Twisted MoS 2 /WS 2 demonstrates a giant ILE energy amplitude ILE amplitudes rely on the stacking nature and chemical elements of heterobilayers Minimal interlayer distance with twist commands wide ILE amplitudes

Advanced Materials, 2021

To improve the performance of metallic catalysts, alloying provides an efficient methodology to d... more To improve the performance of metallic catalysts, alloying provides an efficient methodology to design state‐of‐the‐art materials. As emerging functional materials, rare‐earth metal compounds can integrate the unique orbital structure and catalytic behavior of rare earth elements into metallic materials. Such rare‐earth containing alloy catalysts proffer an opportunity to tailor electronic properties, tune charged carrier transport, and synergize surface reactivity, which are expected to significantly improve the performance and stability of catalysis. Despite its significance, there are only few reviews on rare earth containing alloys or related topics. This review summarizes the composition, synthesis, and applications of rare earth containing alloys in the field of catalysis. Subsequent to comprehensively summarizing and constructively discussing the existing work, the challenges and possibilities of future research on rare‐earth metal compound materials are evaluated.

Applied Catalysis B: Environmental, 2021

Chemical Research in Chinese Universities, 2020

The introduction of plasmons is an important method to solve the insufficient utilization of the ... more The introduction of plasmons is an important method to solve the insufficient utilization of the full spectrum of solar energy by semiconductor catalysts. However, semiconductor catalysts combined with traditional noble metal plasmons(Au, Ag) can only extend the absorption spectrum to partially visible light. In order to further improve the photoenergy absorption efficiency of catalysts, they need to be able to effectively utilize near-infrared light, which has become a new research direction. Recent studies have shown that traditional noble metal plasmons can absorb a part of NIR through special morphology, size control and material composite. At the same time, gratifying achievements have been made in the application of plasmonic semiconductors with broad spectrum absorption in catalysis. This article reviews the principles of generating and regulating plasmonic effects in different catalytic systems. The applications of plasmon absorption of near-infrared light in energy conversion and environmental remediation have also been presented.

Applied Catalysis B: Environmental, 2021

The sluggish catalytic reactivity on the surface of most semiconductors is a common obstacle in d... more The sluggish catalytic reactivity on the surface of most semiconductors is a common obstacle in developing photo-electrochemical (PEC) electrodes. Loading cocatalysts becomes a plausible scenario but remains challenging in the integration with semiconductors due to the complicated interfacial issues. This work introduces an feasible strategy of activating surface reactivity, alternative to cocatalysis, in cooperating with semiconductor photoactivity to boost PEC performance. We apply an ionized argon plasma technology on three-dimensional (3D) nanoporous BiVO 4 (BVO) to controllably generate surface oxygen vacancies, which enable surface activation favoring charge separation and transfer towards water oxidation reaction (WOR). A remarkable photocurrent density of 4.32 mA cm −2 is achieved at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5 G illumination, which is a record among the reported single BVO photoanodes and even surpasses the performances of most cocatalyst-assisted ones. This study provides an alternative solution to sluggish catalytic kinetics on semiconductor photoelectrodes, thus paving a novel avenue to modulate cooperation with photoactivity in PEC technology.

RSC Advances, 2020

Dynamic simulation is employed to reveal the mechanism of electrochemical nanofabrication of nano... more Dynamic simulation is employed to reveal the mechanism of electrochemical nanofabrication of nanoscale probes for atomic resolution imaging in STM.