Publications by authors named "In Hwan Lee"

Photoelectrochemical CO reduction reaction (PEC-CO2RR) into multicarbon (C and C) products is one of the most favorable paths for converting and utilizing atmospheric CO. Although Cu-based photocathodes have unique features that can convert CO into value-added products, they have limited selectivity. In this study, we established the Cu-based heterostructure by introducing the CuO (111) phase on the surface of Cu/Cu(OH) nanorods array (CNA) while integrating Pd cocatalyst to improve the selectivity of the C products via PEC-CO2RR.

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Oxygen evolution reaction (OER) is widely recognized as a bottleneck in the kinetics and activity of decomposition water. Unique geometric design and compositional regulation are important technologies for achieving significant activity and excellent kinetics, but they continue to face obstacles in reaction thermodynamics and kinetic response. Here, a "needle mushroom" shaped Cu2O-NiCo2O4 heterostructure with abundant active sites and optimized conductivity that is grown on the Nickel-foam (NF) (labeled as Cu2O-NiCo2O4/NF-2) is prepared using advanced magnetron sputtering strategies for electrochemical water oxidation.

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We report a novel strategy for vertical alignment of nanorod light emitting diodes (NRLs) by introducing dielectrophoresis (DEP) coupled with a nanohole electrode (NHE). The NHE consists of two electrodes placed at the top and the bottom separated by an insulating layer. This electrode structure allows NRLs to align within the nanoholes due to the nonuniform electric field generated across the entire region of the nanohole when a DEP voltage is applied.

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Developing single-atomic electrocatalysts (SACs) with high activity and stability for electrocatalytic water-splitting has been challenging. Moreover, the practical utilization of SACs is still far from meeting the the theoretical prediction. Herein a facile and easy scale-up fabrication method is proposed for designing a novel carbon-iron-nitrogen (C-Fe-N) electrocatalyst with a single atom electron bridge (C-Fe-N SAEBs), which exhibits lower overpotential and impedance than previously reported electrocatalysts.

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We computed the phase diagram of zigzag graphene nanoribbons as a function of on-site repulsion, doping, and disorder strength. The topologically ordered phase undergoes topological phase transitions into crossover phases, which are new disordered phases with non-universal topological entanglement entropy that exhibits significant variance. We explored the nature of non-local correlations in both the topologically ordered and crossover phases.

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This work evaluates the feasibility of alkaline hydrogen evolution reaction (HER) using Pt single-atoms (1.0 wt %) on defect-rich ceria (Pt/CeO) as an active and stable dual-site catalyst. The catalyst displayed a low overpotential and a small Tafel slope in an alkaline medium.

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The high capacity of electrodes allows for a lower mass of electrodes, which is essential for increasing the energy density of the batteries. According to this, silicon is a promising anode candidate for Li-ion batteries due to its high theoretical capacity. However, its practical application is hampered by the significant volume expansion of silicon during battery operation, resulting in pulverization and contact loss.

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Given the rapidly increasing energy demand and environmental pollution, to achieve energy conservation and emission reduction, hydrogen production has emerged as a promising alternative to traditional fossil fuels because of its high gravimetric energy density, and renewable and environmentally friendly characteristics. Herein, a core-shell hollow-sphere FeO@FeP@nitrogen-doped-carbon (labeled as H-FeO@FeP@NC) with a dual-interface, novel morphology, and superior conductivity is prepared as an advanced bi-functional electrocatalyst for electrochemical overall water splitting using a collaborative strategy comprising of facile self-assembly and phosphating. The prepared catalyst exhibits superior electrocatalytic activity compared to H-FeO@NC and H-FeO for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER).

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Li metal is a promising anode candidate due to its high theoretical capacity and low electrochemical potential. However, dendrite formation and the resulting dead Li cause continuous Li consumption, which hinders its practical application. In this study, we realized N-doped nanoporous carbon for a stable Li metal host composed only of lightweight elements C and N through the simple calcination of a nitrogen-containing metal-organic framework (MOF).

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Monolithic integration of GaSb-based optoelectronic devices on Si is a promising approach for achieving a low-cost, compact, and scalable infrared photonics platform. While tremendous efforts have been put into reducing dislocation densities by using various defect filter layers, exploring other types of extended crystal defects that can exist on GaSb/Si buffers has largely been neglected. Here, we show that GaSb growth on Si generates a high density of micro-twin (MT) defects as well as threading dislocations (TDs) to accommodate the extremely large misfit between GaSb and Si.

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Graphene zigzag nanoribbons, initially in a topologically ordered state, undergo a topological phase transition into crossover phases distinguished by quasi-topological order. We computed mutual information for both the topologically ordered phase and its crossover phases, revealing the following results: (i) In the topologically ordered phase, A-chirality carbon lines strongly entangle with B-chirality carbon lines on the opposite side of the zigzag ribbon. This entanglement persists but weakens in crossover phases.

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We have successfully synthesized a novel form of polyglycerol with an unprecedentedly low degree of branching (DB = 0.08-0.18), eliminating the need for glycidol protection.

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Owing to the increasing demand for the miniaturization and integration of electronic devices, thermal interface materials (TIMs) are crucial components for removing heat and improving the lifetime and safety of electronic devices. Among these, thermal pads are reusable alternatives to thermal paste-type TIMs; however, conventional thermal pads comprise a homogeneous polymer with low thermal conductivity. Composite materials of thermally conducting fillers and polymer matrices are considered suitable alternatives to high-performance pad materials owing to their controllable thermal properties.

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Precise control of multiple structural parameters associated with vinyl polymers is important for producing materials with the desired properties and functions. While the development of living polymerization methods has provided a way to control the various structural parameters of vinyl polymers, the concomitant control of their sequence and regioregularity remains a challenging task. To overcome this challenge, herein, we report the living cationic ring-opening polymerization of hetero Diels-Alder adducts.

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Interest in using an antimicrobial photodynamic treatment (aPDT) for the microbial decontamination of food has been growing. In this study, quercetin, a substance found ubiquitously in plants, was used as a novel exogenous photosensitizer with 405 nm blue light (BL) for the aPDT on foodborne pathogens, and the inactivation mechanism was elucidated. The inactivation of O157:H7 and in PBS solution by the quercetin and BL combination treatment reached a log reduction of 6.

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Zinc-glutarate (ZnGA) is a promising catalyst that can form polymers from CO and epoxides, thereby contributing to the development of CO utilization technologies and future sustainability. One of the obstacles to commercializing ZnGA in polymer industries is its low catalytic activity. In this study, we introduced activated two-dimensional (2D) ZnGA to improve its catalytic activity in polymerization.

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The widely used ZnO quantum dots (QDs) as an electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs) have one drawback. That the balancing of electrons and holes has not been effectively exploited due to the low hole blocking potential difference between the valence band (VB) (6.38 eV) of ZnO ETL and (6.

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Article Synopsis
  • Recent advancements in light-to-fuels conversion have led to the development of a new photocatalyst combining plasmonic gold (Au), ceria (CeO), and graphene (Gr), enhancing hydrogen production significantly.
  • The Au@CeO/Gr photocatalyst achieves an impressive hydrogen production rate of 8.0 μmol mg h and a high maximum quantum yield efficiency of 38.4% at 560 nm, outperforming existing catalysts.
  • Key improvements stem from three factors: the generation of hot electrons via plasmon resonance, the conductivity of the graphene shell aiding in hydrogen evolution reactions, and the effective adsorption of hydrogen atoms on the defect-rich surface of the Au@CeO material.
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Article Synopsis
  • Researchers have developed a method for controlling the growth direction of germanium nanowires using a self-catalytic low-pressure chemical vapor deposition process.
  • By varying the growth temperature, they can selectively produce single-crystalline nanowires oriented in the ⟨110⟩, ⟨112⟩, or ⟨111⟩ directions.
  • This new technique opens up the possibility to explore the unique properties of nanowires based on their orientation and could lead to advancements in semiconductor applications.
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Current infrared thermal image sensors are mainly based on planar firm substrates, but the rigid form factor appears to restrain the versatility of their applications. For wearable health monitoring and implanted biomedical sensing, transfer of active device layers onto a flexible substrate is required while controlling the high-quality crystalline interface. Here, we demonstrate high-detectivity flexible InAs thin-film mid-infrared photodetector arrays through high-yield wafer bonding and a heteroepitaxial lift-off process.

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Diversification of polymer structures is important for imparting various properties and functions to polymers, so as to realize novel applications of these polymers. In this regard, diversity-oriented polymerization (DOP) is a powerful synthetic strategy for producing diverse and complex polymer structures. Multicomponent polymerization (MCP) is a key method for realizing DOP owing to its combinatorial features and high efficiency.

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Noble metal-based surface-enhanced Raman spectroscopy (SERS) has enabled the simple and efficient detection of trace-amount molecules via significant electromagnetic enhancements at hot spots. However, the small Raman cross-section of various analytes forces the use of a Raman reporter for specific surface functionalization, which is time-consuming and limited to low-molecular-weight analytes. To tackle these issues, a hybrid SERS substrate utilizing Ag as plasmonic structures and GaN as charge transfer enhancement centers is presented.

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This work reports the functionalization of azide-alkyne click-based microporous organic polymer (CMOP). The generation of triazolium salts and successive deprotonation induced mesoionic carbene species in hollow CMOP (H-CMOP). Rh(I) species could be coordinated to the mesoionic carbene species to form H-CMOP-Rh, showing excellent heterogeneous catalytic performance in the stereoselective polymerization of arylacetylenes.

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A versatile hydrogen gas sensor is fabricated using Pd@ZnO core-shell nanoparticles (CSNPs), which were synthesized through a hydrothermal route. Effect of oxidation behavior of Pd core to hydrogen sensing is also investigated for Pd@ZnO CSNPs. Accordingly, Pd@ZnO-2 sensor (core-shell sample was calcined in argon) demonstrates the best performance with respect to Pd@ZnO-1 (core-shell sample was calcined in air) and pure ZnO.

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The intersection between nanoscience and additive manufacturing technology has resulted in a new field of printable and flexible electronics. This interesting area of research tackles the challenges in the development of novel materials and fabrication techniques towards a wider range and improved design of flexible electronic devices. This work presents the fabrication of a cost-effective and facile flexible piezoresistive pressure sensor using a 3D-printable carbon nanotube-based nanocomposite.

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