Tae Kyu Kim

Tae Kyu Kim
Pusan National University | PNU · Department of Chemistry

Doctor of Philosophy

About

183
Publications
18,819
Reads
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5,620
Citations
Citations since 2017
70 Research Items
4250 Citations
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Additional affiliations
March 2007 - present
Pusan National University
Position
  • Professor

Publications

Publications (183)
Article
Full-text available
Constructing stable heterostructures with appropriate active site architectures in covalent organic frameworks (COFs) can improve the active site accessibility and facilitate charge transfer, thereby increasing the catalytic efficiency. Herein, a pore-wall modification strategy is proposed to achieve regularly arranged TiO2 nanodots (≈1.82 nm) in t...
Article
The design and construction of highly efficient photocatalytic CO2 conversion systems are extremely desirable for technological, practical, and economic viability. In this study, a 2,2′-bipyridine (bpy)-based ketoenamine covalent organic framework (TpBpy; Tp: 1,3,5-triformylphloroglucinol), which can be prepared on a large scale by a facile and env...
Article
Solar-driven water splitting using a photoelectrochemical (PEC) mechanism is of great practical interest for developing renewable energy systems. In general, BiVO4photoanodes are considered to be a promising candidate for efficient PEC solar energy conversion. However, their solar energy conversion performance is negatively affected by the high rec...
Article
Full-text available
Improving the reversible capacity, fast chargeability, and cyclability of cathode materials are the primary challenges in the development of advanced rechargeable batteries. Herein, we discover the synergetic effects of cobalt ions in achieving a capacity that is approximately equivalent to the theoretical capacity, a highly stable cyclability, and...
Article
Two-dimensional transition metal dichalcogenides (TMDs) with layered nanostructures show promise as non-precious, noble-metal-free water splitting/hydrogen evolution substances. In TMDs, catalytic activity depends on exposed edges because basal planes are inactive. Changing basal planes into catalytically active sites is a challenge. Doping MoS2 wi...
Article
Full-text available
Engineering the electronic structure of metal, N‐doped carbon catalysts is a potential strategy for increasing the activity and selectivity of CO2 electroreduction reaction (CO2RR). However, establishing a definitive link between structure and performance is extremely difficult due to constrained synthesis approaches that lack the ability to precis...
Article
The molybdenum sulfide (MoS2) is a promising low-cost photocatalyst aimed at the hydrogen production reactions, however, obtaining a detailed understanding of its catalytic site has proved to be a challenging task. Several studies indicated that the active sites for catalytic reaction are mainly associated with the edge sites of 2D-layered MoS2, an...
Article
In general, p-type CuBi2O4 (CBO) photocathodes demonstrate excellent solar-to-hydrogen conversion efficiencies but have low quantum yields near the band-edge region (i.e., above 600 nm), which substantially impedes achieving photocurrent densities that match the theoretical values. This is the main obstacle in the construction of photoelectrochemic...
Article
A ternary metal oxide CuBi2O4 has received immense attention in the research field of photoelectrochemical (PEC) water or CO2 reduction owing to its ideal optical bandgap and positive photocurrent onset potential. However, CuBi2O4 photocathodes have limitations regarding charge-carrier separation within and transport across the interface to an n-ty...
Article
The utilization of non-precious and noble-metal free catalysts for the photo conversion of water into hydrogen is of significant interest. In particular, the typical layered MoS2 has attracted interest as a low-cost alternative to platinum in the photocatalytic hydrogen evolution system. However, theoretical studies have suggested that the activity...
Article
Development of low cost, highly efficient and non-noble metal photosystem is of a great significance for promoting the photoproduced carrier’s separation and acting as CO2 reduction sites. Herein, non-noble metal catalysts of TiO2 nanotubes (TNT) and hexagonal ZnIn2S4 nanosheets (ZIS) have been synthesized by simple hydrothermal methods and used fo...
Article
Full-text available
Understanding the ultrafast dynamics of molecules is of fundamental importance. Time-resolved X-ray absorption spectroscopy (TR-XAS) is a powerful spectroscopic technique for unveiling the time-dependent structural and electronic information of molecules that has been widely applied in various fields. Herein, the design and technical achievement of...
Article
Full-text available
Photocatalytic CO 2 reduction to carbon fuels is desirable solutions to replace conventional fossil fuels. Herein, SnS 2 nanosheets (NSs) were fabricated via facile hydrothermal method, which transformed to thinner and more...
Conference Paper
Femtosecond X-ray absorption spectroscopy of the disulfide bridge in L-cystine reveals the thyil radical as the only primary photoproduct which geminately recombines in an ultrafast solvent cage-mediated process, leading to the long-lived perthyil radical.
Article
We employ femtosecond X-ray absorption spectroscopy of [Ru(m-bpy)3]2+ (m-bpy = 6-methyl-2,2′-bipyridine) to elucidate the time evolution of the spin and charge density upon metal-to-ligand charge-transfer (MLCT) excitation. The core-level transitions at the Ru L3-edge reveal a very short MLCT lifetime of 0.9 ps and relaxation to the lowest triplet...
Article
NiFe -layered double hydroxides (LDH) are fast, responsive oxygen evolution co-catalysts (OECs) for photoelectrochemical (PEC) water splitting due to their extraordinary photo charge carrier transport properties, easy modulation of defect states, and low preparation cost. However, in NiFe-LDH, major catalytic active sites are situated at the edge s...
Article
The integration of photosensitizers with low-cost and non-toxic metal oxides is a promising strategy to design heterogeneous photocatalysts for CO2 reduction. Herein, p–n heterojunction photocatalysts (T-CoPPcs) consisting of p-type polymeric cobalt phthalocyanines (CoPPcs) as a photosensitizer coupled with n-type TiO2 nanorods were fabricated thro...
Article
Dual‐atom site catalysts (DACs) have emerged as new frontier in heterogeneous catalysis because the synergistic effect between adjacent metal atoms can promote their catalytic activity while maintaining advantages of single‐atom site catalysts such as almost 100% atomic efficiency and excellent hydrocarbon selectivity. Herein, Co‐based atom site ca...
Article
Dual‐atom site catalysts (DACs) have emerged as new frontier in heterogeneous catalysis because the synergistic effect between adjacent metal atoms can promote their catalytic activity while maintaining advantages of single‐atom site catalysts such as almost 100% atomic efficiency and excellent hydrocarbon selectivity. Herein, Co‐based atom site ca...
Article
Two-dimensional (2D) g-C3N4 (CN) has garnered massive interest for photocatalytic applications owing to its excellent photon contact area, visible-light absorption, and easy transport of photogenerated charge carriers to the surface. However, bulk CN suffers from intrinsically poor charge separation, limited specific surface area, and insufficient...
Article
The selection of layered number and time-course destruction of layers may affect the charge transfer between 2D-to-1D heterostructure, making it possible to improve the efficiency of solar-to-hydrogen evolution. Herein, we demonstrate a simple, low-cost systematic protocol of 2D-WSe2 nanolayer numbers ranging from 7 to 60 aiding the ultrasonication...
Article
Two-dimensional (2D) organic semiconductors, such as graphitic carbon nitride (g-C3N4), have gained extensive attention as a green alternative and possible route for photocatalytic applications due to their appropriate bandgap for the effective utilization of the visible light region. This paper presents the development of few-layered 2D exfoliated...
Article
Ru L3‐edge time‐resolved X‐ray absorption spectroscopy (TR‐XAS) was applied to unravel photo‐induced excited state dynamics of solvated [Ru(m‐bpy)3]2+ (m‐bpy = 6‐methyl‐2,2′‐bipyridine) complex. The Ru L3‐edge probes 2p core‐level transitions, enabling to monitor the electronic structure of excited 3dd state. TR‐XAS and time‐dependent density funct...
Article
The dynamics of photodissociation of oxalyl bromide was investigated near 265 and 234 nm using the method of visualizing the velocity map in combination with multiphoton ionization with state-selective [2 + 1] resonance amplification. The distribution of translational energy levels and the parameters of the Br atom ( 2 P J , J = 3/2, 1/2) are extra...
Article
We demonstrate for the case of photoexcited [Ru(2,2'-bipyridine)3]2+ how femtosecond resonant inelastic X-ray scattering (RIXS) at the ligand K-edge allows one to uniquely probe changes in the valence electronic structure following a metal-to-ligand charge-transfer (MLCT) excitation. Metal-ligand hybridization is probed by nitrogen-1s resonances pr...
Article
Clean and sustainable hydrogen fuel production through photocatalytic water splitting is an ideal strategy to achieve a higher grade of sustainability. Metal–organic frameworks (MOFs) based photocatalysts have recently attracted significant attention as a new type of photocatalysts owing to their excellent light harvesting capability and remarkable...
Article
Full-text available
X-ray absorption near-edge structure (XANES) spectroscopy provides element specificity and is a powerful experimental method to probe local unoccupied electronic structures. In the soft x-ray regime, it is especially well suited for the study of 3d-metals and light elements such as nitrogen. Recent developments in vacuum-compatible liquid flat jets...
Article
Full-text available
The conversion of anthropogenic CO2 to value-added chemicals through solar-driven catalysis has been proposed as a promising approach to overcome the problems associated with high CO2 emissions and to address the energy crisis. Although a variety of materials have been investigated for catalysts in the production of high-energy fuels from CO2 in wa...
Article
The performance of oxide photoanodes constructed with hematite (Fe2O3) nanostructures is among the best for low-cost photoelectrochemical water-splitting cells. However, due to limited light absorption capacity, a high photogenerated charge carrier recombination rate, and sluggish surface oxygen evolution reaction (OER) kinetic on the surface, the...
Article
Full-text available
Superstructures with hollow cage‐like hierarchical ordering play a predominant role in various applications owing to their unique properties, such as low density, an interior void, a high surface‐to‐volume ratio, and excellent permeability for charge and mass transport. Low‐cost hollow cage‐like copper sulfide superstructures are competitive candid...
Cover Page
The Cover Feature shows the integration of indium phosphide (InP) quantum dots on CdS nanorods (NRs) for the photocatalytic CO2 conversion under solar light irradiation. In their Full Paper, K. H. Do, D. P. Kumar et al. explain the simple and inexpensive process for the preparations of pure InP QDs and demonstrate the enhanced sunlight‐driven photo...
Article
Full-text available
Photocatalytic conversion of CO2 into storable fuels is an attractive way to simultaneously address worldwide energy demands and environmental problems. Indium phosphide (InP) quantum dots are semiconducting QDs with enormous potential for solar‐driven CO2 reduction. Their advantages include a tunable bandgap, diverse surface chemistry, and nontoxi...
Article
Full-text available
Development of earth-abundant, low cost, skeletal-type copper sulfide superstructures plays a prominent role in various potential applications, owing to the properties of superstructures such as excellent permeability of charge and mass. In this study, we synthesized the hollow superstructures of crystallinity-controlled polyhedral skeletal-type co...
Article
Photoelectrochemical (PEC) water-splitting performance can be expressed as the product of efficiencies of light absorption (ηabs), charge separation (ηsep) and charge transfer (ηtrans) processes. In BiVO4 photoanodes, the ηtrans has been greatly enhanced by integrating various low-price oxygen evolution electrocatalysts but improving ηabs×ηsep effi...
Article
Photocatalytic water splitting by semiconductor nanostructures is a challenging chemical process for harnessing abundant solar energy and obtaining clean H2 fuel. To that end, photocatalysts that comprise efficient light-harvesting semiconductor nanostructures and noble metal-free robust co-catalysts have attracted considerable attention. In this s...
Article
Ni3Se2 and Co-doped Ni3Se2 cauliflower-like nanostructures are synthesized using a simple and feasible electrochemical deposition technique. Electrochemical measurements of the resultant nanostructures in 1 M KOH electrolyte solution revealed that the energy storage performance of the cauliflower-like Ni3Se2 nanostructures was considerably improved...
Article
2D-MoS2 nanostructures are attractive co-catalysts for photocatalytic hydrogen evolution due to their suitable water reduction potentials and high stability. However, the catalytic activity of MoS2 is greatly limited by the catalytically inert basal planes. Doping of transition-metal ions into MoS2 structure is an effective way to activating the ba...
Article
We have employed a range of ultrafast X-ray spectroscopies in an effort to characterize the lowest energy excited state of [Fe(dcpp)2]2+ (where dcpp is 2,6-(dicarboxypyridyl)pyridine). This compound exhibits an unusually short excited-state lifetime for a low-spin Fe(II) polypyridyl complex of 270 ps in a room-temperature fluid solution, raising qu...
Conference Paper
Full-text available
We report on the UV-induced photochemistry of the biologically relevant sulfur-containing thiol group and the disulfide bond in solution using picosecond X-ray absorption spectroscopy at the sulfur K-edge. This study provides element-specific insight into the 267-nm induced photo-chemistry of two model compounds, an aromatic thiol and an aliphatic...
Article
Full-text available
Gas-phase ion-molecule reactions of Ti + with 1,1,1-trifluoroacetone were studied by laser ablation/molecular-beam method and density function theory calculations. In the reaction of the Ti + ions with acetone, Ti + ion insertion into the C=O bond is the preferred decomposition pathway and produce TiO + predominantly. Substitution of CH 3 in aceton...
Article
Solar-driven semiconductor-based molecular hydrogen production is an ideal protocol for converting abundant solar energy to green fuel. However, this process suffers from costly semiconductor nanostructures, low efficiency, and poor stability. Here, we design a noble-metal-free photocatalyst, CdS-NiFe layered double hydroxide (LDH) nanocomposite, w...
Article
Exploring active and stable photocatalysts is an essential requirement for boosting the efficiency of photocatalytic water splitting to obtain clean hydrogen fuel. Here, a few layered black phosphorus/MoS2 (BP-MoS2) nanohybrid was successfully prepared and verified it for photocatalytic hydrogen evolution using CdS nanorods as light absorbers. The...
Article
Development of novel low price porous nanostructures with robust photocatalytic hydrogen generation rate and high durability is critical to help to meet the future energy demand. A prominent number of sunlight active semiconductor photocatalyst nanostructures have been formulated for the aforementioned photocatalytic reactions. However, their pract...
Article
Full-text available
Ultrafast isomerization reactions underpin many processes in (bio)chemical systems and molecular materials. Understanding the coupled evolution of atomic and molecular structure during isomerization is paramount for control and rational design in molecular science. Here we report transient X-ray absorption studies of the photo-induced linkage isome...
Article
We have investigated dimethyl disulfide as the basic moiety for understanding the photochemistry of disulfide bonds, which are central to a broad range of biochemical processes. Picosecond time-resolved X-ray absorption spectroscopy at the sulfur K-edge provides unique element-specific insight into the photochemistry of the disulfide bond initiated...
Article
Carbon nanotubes (CNTs) have enormous potential for application due to their extreme hydrophobicity. Further, their physico-chemical properties can be modified by surface functionalization. Acid functionalization of CNTs is one of the basic methodology for modification of their electro-chemical properties, resolving the poor dispersion capability,...
Article
The hollow materials have played a significant role in cutting-edge innovations for energy conversion due to their peculiar properties and their wide range of potential applications. These materials show great promise for the development of cleaner power sources to address growing environmental concerns at a time of increasing global demand for ene...
Article
Designing porous nanostructures with unprecedented functions and an effective ability to harvest the maximum energy region of the solar spectrum and suppress the charge-carrier recombination rate is offering promising potential for sustainable energy production. Herein, we report a new, highly active, noble-metal-free, and redox-mediator-free Z-sch...
Article
The development of efficient, cost-effective, clean, and renewable ways to generate hydrogen is crucial to fulfill energy demand and relieve environmental concerns. The layered nanostructures of two-dimensional transition metal dichalcogenides (TMDs) are promising non-precious, noble-metal-free materials for use as hydrogen evolution reaction photo...
Article
The development of novel highly efficient noble metal-free co-catalysts for enhanced photocatalytic hydrogen production is of great importance. Herein, we report the synthesis of novel and highly efficient noble metal-free ultra-thin MoS2 (UM) layers on exfoliated reduced graphene oxide (ERGO) nanosheets as a cocatalyst for CdS nanorods (ERGO/UM/Cd...
Article
Transition-metal dichalcogenides (TMD) have emerged as a fascinating new class of noble-metal-free materials for photocatalytic hydrogen evolution from the water. Recently, numerous approaches have been established to develop single- or few-layered TMDs to improve their physical properties. Although WS2 has a higher intrinsic electric conductivity...
Article
Semiconductor-based photocatalysis is a green method for the removal of toxic organic pollutants by decomposition into harmless products. However, traditional single-component semiconductors are unable to reach high degradation efficiencies due to excessive photo charge carrier’s recombination. Hybrid nanocomposite photocatalysts are a promising st...
Article
We demonstrate a simple and effective approach to modulate the active sites and electronic properties of MoS2 using hydrazine assisted liquid exfoliation for enhancing its co-catalytic activity in photocatalytic hydrogen evolution. The resulting hydrazine assisted liquid exfoliation formation of ultrathin MoS2 (HUT-MoS2) nanosheets integrated on Cd...
Article
We applied time-resolved sulfur-1s absorption spectroscopy to a model aromatic thiol system as a promising method for tracking chemical reactions in solution. Sulfur-1s absorption spectroscopy allows tracking multiple sulfur species with a time-resolution of ~70 ps. Experimental transient spectra combined with high-level electronic structure theory...
Article
A paste-type certified reference material (CRM) of tomato was developed for accurate elemental analysis of canned foods. Accurate mass fractions of cadmium (Cd), lead (Pb), and tin (Sn) in the tomato paste CRM were determined by isotope dilution inductively coupled plasma mass spectrometry. The certified values and their expanded uncertainties (k=2...
Article
An arsenobetaine (AsB) standard solution with metrological traceability to the International System of Units was developed as a calibration standard for the quantitative analysis of AsB. An arsenic-specific mass balance method was established for the certification of the AsB standard solution. The accurate mass fraction of total arsenic in the solu...
Article
Solar-driven photocatalytic hydrogen evolution is important for bringing solar energy-to-fuel energy conversion process to reality. However, the lack of highly efficient, stable, and non-precious photocatalysts or catalysts designed completely with expensive noble metals have remained elusive, which hampers their large-scale industrial application....
Article
Ultra-dispersed bimetallic nanomaterials have attracted much attention in the hydrogenation of highly toxic aromatic nitro compounds to aromatic amines owing to their high stability, superior activity, reusability, and unique optical and electronic properties, as compared to monometalic nanocrystals. However, the lack of facile and economically con...
Article
Photocatalytic hydrogen evolution reaction using semiconductor nanostructures has received considerable attention to tackle energy and pollution problems. Although several semiconductor photocatalysts have been developed, materials satisfactory in all aspects (e.g., economically and eco-friendly with high efficiency) are still to be developed. Here...
Article
Cerium-based nanohybrids have attracted considerable attention in photocatalytic research owing to their remarkable potential in the photodegradation of environmental pollutants. However, the process of nanohybrid formation suffers from complex operations with specialized equipment, extreme conditions, long durations, and low yields, making it infe...
Article
The inferior utilization efficiency of light is the main obstacle to the practical application of traditional photocatalysts such as TiO2 and ZnO. In this regard, the development of novel photocatalysts with the capability of harvesting full spectrum light (from ultraviolet (UV) to near-infrared (NIR)) energy is a promising solution for solar energ...
Article
Development of noble metal free, novel and highly efficient cocatalysts is of great significance in favor of high performance towards elevated photocatalytic hydrogen production. The present existing technology for photocatalytic water splitting primarily involves the use of noble metals, such as Pt, as cocatalysts on semiconductor materials result...
Article
Charge carrier recombination and durability issues are major problems in photocatalytic hydrogen (H2) evolution processes. Thus, there is a very important necessitate to extend an efficient photocatalyst to control charge-carrier dynamics in the photocatalytic system. We have developed copper molybdenum sulfide (Cu2MoS4) nanosheets as co-catalysts...
Article
Facile preparation of metal–organic framework (MOF)-derived earth-abundant nickel phosphide (Ni2P) by a simple, cost-effective procedure is described. Ni2P is recognized as a suitable replacement for expensive noble metal co-catalysts used for H2 production by water splitting. Ni2P nanoparticles were used to prepare a Ni2P/CdS composite with improv...
Article
Solar photocatalytic water treatment has emerged as a promising way to provide clean water. However, most traditional photocatalysts (TiO2, ZnO, etc.) are active only under ultraviolet light and have high recombination rates of photoinduced electron-hole pairs; therefore, they are not sufficient to fulfill all of the demands of practical applicatio...
Article
Cerium-based nanohybrids have attracted considerable attention in photocatalytic research owing to their remarkable potential in the photodegradation of environmental pollutants. However, the process of nanohybrid formation suffers from complex operations with specialized equipment, extreme conditions, long durations, and low yields, making it infe...
Article
Cerium-based nanohybrids have attracted considerable attention in photocatalytic research owing to their remarkable potential in the photodegradation of environmental pollutants. However, the process of nanohybrid formation suffers from complex operations with specialized equipment, extreme conditions, long durations, and low yields, making it infe...