In Sun Cho

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Verified

In Sun verified their affiliation via an institutional email.

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• Ph.D
• Professor (Full) at Ajou University

The simultaneous optimization of the bulk and surface characteristics of photoelectrodes is essential to maximize their photoelectrochemical (PEC) performance. We report a novel one-pot hydrothermal synthesis of textured and surface-reconstructed BiVO4 photoanodes (ts-BVO), achieving significant improvements in PEC water splitting. By controlling p...

Additional experimental evidence was provided to demonstrate the growth of the [001]-textured BiVO 4 on polycrystalline substrates.

The conversion of solar energy into chemical fuel via photoelectrochemical (PEC) water splitting shows great promise for solving the energy crisis, achieving carbon neutrality, and a sustainable future. Iron (Fe)-based materials have attracted tremendous attention from various light absorber materials due to their earth abundance, high light absorp...

Bismuth vanadate (BiVO 4 , BVO) with a monoclinic crystal structure has attracted significant interest in photoelectrochemical (PEC) and photocatalytic (PC) oxidation that are utmost critical processes to producing clean hydrogen fuels from solar energy. BVO has a suitable bandgap (2.4 eV), which enables it to absorb sunlight up to a wavelength of...

Harnessing renewable solar energy for solar desalination shows great promise for addressing freshwater scarcity. However, conventional solar desalination suffers from low photothermal conversion and excessive heat dissipation, limiting its practicality for meeting water demand. Interfacial solar steam generation (ISSG) has emerged to address these...

Harnessing renewable solar energy in interfacial solar steam generation (ISSG) can address global freshwater scarcity. Herein, we present copper phosphate (Cu 3 P 2 O 8 ; CuPO) as a novel photothermal material with broad visible-to-near-infrared (Vis-to-NIR) absorption capabilities, suitable for interfacial solar steam generation (ISSG). CuPO demon...

Surface reconstruction, reorganizing the surface atoms or structure, is a promising strategy to manipulate materials' electrical, electrochemical, and surface catalytic properties. Herein, a rapid surface reconstruction of indium sulfide (In2S3) is demonstrated via a high‐temperature flame treatment to improve its charge collection properties. The...

Porosity control and facet engineering of electrocatalysts are critical for sustainable hydrogen production and wastewater upcycling into value-added chemicals. Herein, we report the sol-gel synthesis of a nanoporous faceted cupric oxide (nf-CuO) electrocatalyst film via a controlled polyesterification reaction. The formation mechanism of the uniqu...

Solar steam generation (SSG) has emerged as a sustainable solution for addressing water scarcity, and ongoing research has resulted in the development of various photothermal materials that demonstrate exceptional light-absorption capabilities and overall performance. This study presents mechanochemically activated silicon (Si60), which exhibits a...

Effective harnessing of renewable solar energy in interfacial solar steam generation (ISSG) is a promising solution for addressing freshwater scarcity worldwide. Therefore, the development of photothermal materials plays a pivotal role in achieving efficient ISSG performance. This paper reports on an innovative photothermal material, copper phospha...

The development of technologies for electromagnetic wave contamination has garnered attention. Among the various electromagnetic wave frequencies, for high frequencies such as those in the K and Ka ranges, there is a limitation of using only the properties of a single material. Therefore, it is necessary to improve the absorption coefficients by in...

Spinel manganates (AMn2O4; A = Co, Ni, Cu, Zn, and Fe; collectively referred to as AMO) are promising electrode materials for water electrolyzers, pseudocapacitors, and batteries owing to their inherent advantages such as valence variability, high catalytic activity, conductivity, stability, low‐cost, and environmental friendliness. Nanostructured...

High entropy alloys (HEAs) composed of multi‐metal elements in a single crystal structure are attractive for electrocatalysis. However, identifying the complementary functions of each element in HEAs is a prerequisite. Thus, VxCuCoNiFeMn (x = 0, 0.5, and 1.0) HEAs are investigated to identify the active role of vanadium in improving the electrocata...

Proper treatment of decomposable plastic waste and plastic waste upcycling for value-added chemical recovery have increasing attention in recent years. Tricalcium phosphate (TCP; Ca3P2O8) is one of the most studied biomaterials for bone replacement and regeneration. Herein, we endeavored to apply the TCP catalyst to a thermocatalytic conversion pro...

Spinel zinc ferrite (ZnFe2O4, ZFO) is a potential photoanode material for photoelectrochemical (PEC) water splitting because of its ideal bandgap (1.9–2.1 eV) and superior chemical stability in aqueous solutions. However, the low charge collection efficiency significantly hinders the improvement in PEC activity. Herein, we report an ultrafast and e...

Photocatalysis offers opportunities to degrade recalcitrant organic pollutants without adding treatment chemicals. Nitrogen (N) vacancy is an effective point-defect engineering strategy to mitigate electron-hole recombination and facilitate hydroxyl radical (•OH) production via superoxide radical (O2•-) generation during photocatalytic application...

Water Splitting In article number 2200572, In Sun Cho, Uk Sim, and co‐workers present accelerated water splitting with sulphur‐rich Co‐NiO heterostructure encapsulated on N‐rich carbon nanofibers (SCNO@N‐CNF) synthesized via a simple and efficient electrospinning technique. The design and engineering of multiple active elements in a single electroc...

Interfacial solar desalination is a promising method to sustainably address global water scarcity. Thus far, it has been a challenge to find photothermal materials with both efficient light absorption and low thermal conductivity. This study is the first to explore a layered oxychalcogenide of bismuth copper oxysulfide (BiCuSO, BCSO) nanosheets as...

A multifaceted Mo:BiVO4 (mf‐BVO) photoanode is grown on F‐doped‐SnO2 substrates via achemical bath deposition, and the crystal reconstruction process of mf‐BVO is found to boost the charge transport efficiency significantly for photoelectrochemical (PEC) water splitting. The mf‐BVO exhibits columnar grains with an uncommon (121) texture with high‐i...

A series of divalent metal orthophosphate compounds, A3(PO4)2 (A = Ca, Sr, Ba, Mg, Zn, Ni, Cu), were synthesized using a solid-state reaction method. The densification behavior and optical properties of the synthesized powders were investigated using differential thermal analysis, dilatometry, and UV–Vis diffuse reflectance spectroscopy. The crysta...

Electrochemical water splitting is the eco‐friendly route to generate green hydrogen, which is recognized as sustainable energy for the future. However, the cost, operational efficiency, and long‐term durability of the electrochemical water splitting rely on the choice of the electrocatalysts. Hence, developing a superior design strategy is an impo...

Facet engineering, which exposes desired crystal planes, is an effective method for manipulating the surface adsorption and catalytic reactivity of electrocatalysts used in water splitting. Herein, we report the synthesis of faceted CuMn2O4 (f-CMO) nanoparticles via polyol-mediated annealing, in which ethylene glycol plays a crucial role in the for...

Colloidal CeO2 quantum dots (CeQDs) were synthesized to boost the photoelectrochemical (PEC) water-splitting activity of bulky-crystalline BiVO4 (BVO) photoanode via rapid hole extraction. CeQDs with average sizes of 1.8, 2.3, and 3.0 nm were prepared by adjusting the reaction temperature. They exhibited high crystallinity and dispersibility in an...

Constructing heterostructure by coupling structures with a one-dimensional morphology is a promising method to enhance photoelectrodes' charge collection and light absorption properties for photoelectrochemical water splitting. Herein, we aimed to synthesize a BiVO4 (BVO)/Sb-doped SnO2 (SSO) nanorods-axial-heterostructure (NAH) via the facile solut...

After overcoming 25% of the power conversion efficiency (PCE) for the perovskite solar cells (PSCs), lots of efforts are being put into modularization. In order to advance this, the development of passivation materials that can operate effectively without affecting the cell areas is essential. This study introduces the 1‐decyl‐3‐methylimidazolium b...

Polyester fiber is a high-molecular-weight compound made from fossil fuels and is used in various synthetic fiber manufacturing processes. In this study, we performed non-catalytic and catalytic pyrolysis experiments using cobalt oxide as a catalyst to recover energy from polyester fiber. The experiment was carried out between 500–900 °C in the pre...

Heterostructure engineering, combining dissimilar materials into a single substrate, allows the alteration of the optical, electrical, and electrochemical properties of photoelectrodes for photoelectrochemical (PEC) water splitting. Herein, we successfully synthesized a novel dual-textured BiVO4 / Sb:SnO2 heterostructure as a photoanode for PEC wat...

Engineering point defects such as metal and oxygen vacancies play a crucial role in manipulating the electrical, optical, and catalytic properties of oxide semiconductors for solar water splitting. Herein, we synthesized nanoporous CuBi2O4 (np-CBO) photocathodes and engineered their surface point defects via rapid thermal processing (RTP) in contro...

Stacked perovskite films—laminated films in particular—have garnered considerable attention owing to their excellent potential for various applications. However, perovskite solar cells fabricated using laminated perovskite films exhibit a critically low power conversion efficiency. To overcome this limitation, in this paper, we report the surface a...

Cupric oxide (CuO) is an attractive photocathode material for tandem-type photoelectrochemical water-splitting because it has a small bandgap (1.2 – 1.5 eV), high absorption coefficient, suitable band-edge position, and favorable characteristics such as earth-abundancy, low cost, and non-toxicity. Here, we report a sharp-edged nanoflakes array (SNA...

Heterostructure engineering, combining dissimilar materials into a single substrate, allows the alteration of the optical, electrical, and electrochemical properties of photoelectrodes for photoelectrochemical (PEC) water splitting. Herein, we successfully synthesized a novel dual-textured BiVO4 / Sb:SnO2 heterostructure as a photoanode for PEC wat...

Over the recent past, lead-based halide perovskite materials have drawn significant attention due to their excellent optical and electrical properties for solar cells and optoelectronics applications. However, the toxicity of lead elements and instability under ambient conditions leads to develop alternative compositions. Herein, we report a novel...

High entropy alloys (HEA), multicomponent (5 or more) alloys with an equiatomic or a near-equiatomic composition, provide a unique platform with which to engineer surface composition and active sites for the development of efficient electrocatalysts. Herein, we endeavor to introduce a high entropy alloy (HEA) of CuCoNiFeMn as an active model system...

We report a novel solution-processed copper-aluminate (CuAl2O4, CAO) film as a photocathode for photoelectrochemical water-splitting. Two types of CAO were synthesized, porous- and dense-CAO, with the controlled addition of polyvinylpyrrolidone. Importantly, we found that lithium-ion (Li⁺) incorporation onto CAO has profound effects. It simultaneou...

Layered-type metal phosphates of BaNb2-xTaxP2O11 (x = 0, 0.5, 1.0, 1.5, and 2.0) were synthesized using a solid-state reaction method. The photophysical, optical, and photocatalytic hydrogen production properties of the resulting powders were investigated for the first time. Phase-pure and homogeneous powders with irregular morphologies were obtain...

The construction of a heterostructured nanowire array allows the manipulation of the interfacial, surface, charge transport, and transfer properties simultaneously, offering new opportunities to achieve multi-functionality for various applications. Herein, we developed a facile thermal evaporation and post-annealing method to synthesize ternary-Zn2...

Copper bismuthate (CuBi2O4, CBO) has attracted attention as a promising photocathode material for photoelectrochemical (PEC) water-splitting because of its small bandgap (1.6–1.8 eV), high internal photovoltage, and moderate stability in aqueous media. Herein, we report a novel solution synthesis method to fabricate bulky crystalline CBO photocatho...

A key challenge in photoelectrochemical water-splitting is the development of photoanodes with improved chemically active and optically efficient. While various nanostructures in heterogeneous materials have been investigated as a potential electrode, existing structures/compositions are still insufficient to meet such demand. Here, we report a sca...

Copper pyro‐, ortho‐, and tetra‐phosphate compounds (Cu2P2O7, Cu3P2O8, and Cu4P2O9) with the general composition, CuxP2O5+x (x = 2, 3, 4), were prepared through the conventional solid‐state synthesis route, and their optical properties and visible‐infrared light‐induced photocatalytic activities were investigated for the first time. The copper phos...

Bismuth vanadate (BiVO4, BVO) is a promising photoanode material for photoelectrochemical water-splitting, and it is mostly prepared using a sol-gel spin-coating method. BVO often exhibits poor PEC performance without modifications such as doping, co-catalyst deposition, and heterojunction formation. Herein, we report an alternative method to depos...

Texturing, i.e., preferentially oriented deposition of a film with a specific crystallographic direction, enables the manipulation of the charge transport properties and surface reactivity of photoelectrodes for solar water-splitting. The advancement of solar water-splitting systems under neutral conditions is a vital strategy to reduce the economi...

In this work, a facile hydrothermal method is proposed to fabricate Nb-doped WO3 nanotriangle thin films, and their band edge properties and photoelectrochemical water splitting activity were explored. The process of doping and thin film formation was simultaneously achieved in a single step hydrothermal condensation of peroxopolytungstic acid solu...

The design of heterostructured multilayer oxide films for photoanodes enables the control of interfacial, charge transport/transfer and optical properties as well as stability, thus resulting in efficient photoelectrochemical (PEC) water splitting. Here, we report a triple-layered TiO2/BiVO4/SnO2 (T/B/S) photoanode that shows improved PEC water-oxi...

Layered perovskite compounds of SrBi2Nb2−xVxO9 (x = 0.0, 0.02, 0.04, 0.06, and 0.08) were synthesized via a solid-state reaction method. Their optical properties, electronic band structures, and photocatalytic activities under visible light irradiation were investigated for the first time. The incorporation of vanadium into the SrBi2Nb2O9 lattice r...

Correction for ‘Boosting the solar water oxidation performance of a BiVO 4 photoanode by crystallographic orientation control’ by Hyun Soo Han et al. , Energy Environ. Sci. , 2018, 11 , 1299–1306.

Photoelectrochemical (PEC) water splitting has been extensively studied as a method to convert sunlight and water to hydrogen. Among the many obstacles facing PEC water splitting, a critical challenge is the lack of efficient photoanodes for the water oxidation reaction. Here, we report a n-n⁺ type-II homojunction of Zn:BiVO4/Mo:BiVO4, which improv...

Next-generation solar cells, such as dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs), are fabricated in a configuration where light absorbers are located between the electron transporting layer (ETL) and the hole transporting layer (HTM). Although the most efficient DSSCs and PSCs have been fabricated using TiO2 as the ETL, TiO...

Copper ferrite (CuFe2O4) possesses an indirect bandgap in the range of 1.54–1.95 eV. It is used as an attractive p-type photocathode in photoelectrochemical (PEC) water splitting, and theoretically it can yield a maximum photocurrent density of ~27 mA/cm2 and a maximum solar-to-hydrogen conversion efficiency of ~33%. To date, only a few reports hav...

In this work, we propose the synthesis and investigate the band edge properties of WO3 thin films having an optimum amount of oxygen vacancies for efficient PEC applications. A facile hydrothermal route is utilized to fabricate WO3 thin films, and a low, moderate, and high number of oxygen vacancies are introduced via annealing in O2, air, and H2,...

Detection of hydrogen (H2) over a wide concentration range (from parts-per-million levels to 4%) is necessary for safety in using hydrogen-fuel cell systems. For this purpose, our development of H2 sensitive nanohybrids of reduced graphene oxide (rGO) and chemochromic palladium-decorated molybdenum trioxide (Pd:MoO3) nanoflakes is presented. Additi...

In this article, the authors present the synthesis of Sn–1.0Ag–0.5Cu (SAC105) alloy embedded with zirconium oxide nanoparticles using simple mechanical blending and casting route. The cast samples were characterized in terms of microstructural evolution, wetting, microhardness, and drop test reliability. The characterizations were performed by usin...

Deoxygenation of graphene oxide is a low-cost and effective way to yield graphene (i.e., reduced graphene oxide - RGO) for many applications. However, choices of reduction approach and reduction time need consideration due to damaging pre-existing materials on electronic devices. Here, we found a facile and eco-friendly route that was based on the...

Materials with low crystal symmetry often exhibit anisotropic properties, allowing the tuning of their physical and chemical properties via crystallographic orientation and exposed facet control. Herein, we demonstrate, for the first time, that pristine BiVO4 with a preferred [001] growth orientation and exposed (001) facets exhibits excellent intr...

The influences of Mg and Sr co-addition on the phase transformation and densification behavior of calcium pyrophosphate (Ca2P2O7, CPP) were investigated. We found that the addition of an optimum content of Mg increases bulk density of CPP ceramic because it restrains the volume-expansion (i.e., crack formation) that occurs due to the phase transfor...

Copper tin oxide, CuSnO3 (CSO), is an amorphous oxide semiconductor with a band-gap of 2.0-2.5eV, and it is an attractive material for diverse applications such as transparent conducting oxides, transistors, and optoelectronic devices. In this study, we fabricated CSO thin films on fluorine-doped tin oxide (FTO)/glass substrates using a facile sol-...

Cu-based compounds can be a good candidate for a low cost solar cell material. In particular, CuxO (x: 1–2) has a good visible light absorbing bandgap at 1–2 eV. As for using nanostructures in solar cell applications, metal nanoparticle-induced localized plasmon resonance is a promising way to increase light absorbance, which can help improve the e...

The thermal transport growth of various metal oxide (MOx) nanostructures using graphene as a catalytic layer was studied. Graphene was synthesized by Cu-catalyzed chemical vapor deposition and transferred onto a SiO2-covered Si substrate using bubble transfer methods. Due to the catalytic activity of the atomic-thick carbon layer, control of the po...

A nanodome structured BiVO4/GaOxN1−x (BVO/GaON) bilayer photoanode that is prepared by a facile solution method, and that exhibits an improved photoelectrochemical water-oxidation performance is reported. GaON porous nanospheres with an average size of ≈300 nm are first synthesized by a nitridation (NH3 flow, 800 °C) of Ga4(OH)10SO4 nanospheres. Th...

Three bismuth sillenite compounds with the general composition, Bi12XO20 (X = Si, Ge, Ti), were prepared by a conventional solid state synthesis route and their local crystal structure, light absorption and visible-light induced photocatalytic activities were systematically investigated. The prepared powder samples show comparable particle size dis...

An important pathway for cost-effective light energy conversion devices, such as solar cells and light emitting diodes, is to integrate III-V (e.g., GaN) materials on Si substrates. Such integration first necessitates growth of high crystalline III-V materials on Si, which has been the focus of many studies. However, the integration also requires t...

Coupling dissimilar oxides in heterostructures allows the engineering of interfacial, optical, charge separation/transport and transfer properties of photoanodes for photoelectrochemical (PEC) water splitting. Here, we demonstrate a double-heterojunction concept based on a BiVO4/WO3/SnO2 triple-layer planar heterojunction (TPH) photoanode, which sh...

We report a modified TiO2/p-Si electronic structure that uses ultraviolet exposure for the incorporation of H. This structure was characterized using various photoelectron spectroscopic techniques. The ultraviolet (UV) exposure of the TiO2 surface allowed the Fermi energy level to be tuned by the insertion of H radicals, which induced changes in th...

We report a facile one-pot synthesis of self-assembled quantum-rod (sub-10 nm) TiO2 spheres (SQR-TiO2) via a low-temperature solution method and demonstrate the impact of SQR-TiO2 on the charge transport/collection properties of photoelectrochemical devices. The effects of dissolved ions (e.g. Na⁺ and Cl⁻) on the particle morphology was investigate...

Growth of ZnO thin film on conventional Si (100) substrate using atomically thin graphene as a buffer layer has been studied. The graphene buffer layer was synthesized by Cu-catalyzed chemical vapor deposition method and transferred on Si (100) using well-established polymer coating and Cu etching techniques. The ZnO film with (0002) preferred orie...

Yellow-emitting nanorod phosphors Ba2-2xMg(PO4)2:Eu2x2+ (x = 0.01—0.09) are precipitated from stoichiometric aqueous solutions of Ba(NO3)2, Mg(NO3)2, (NH4)2HPO4, and Eu2O3 (pH 7—11 adjusted with NaOH, 90 °C, 6 h) followed by annealing (5%H2/N2, 600—800 °C, 2 h).

The realization of efficient photoelectrochemical water splitting requires effective integration of earth-abundant active oxygen evolution catalysts (OECs) with diverse photoanodes. Although many good OECs have been reported based on conductive substrates under dark, further studies are needed to evaluate their performance when integrated with dive...

We report fine tuning of emission color of Ce-doped yttrium aluminum garnet (Y3Al5O12:Ce3+, YAG:Ce) nanophosphor-based white light-emitting diodes (WLED), by coating CdSe/CdS/ZnS quantum dots (QDs) onto the surface of the YAG:Ce nanoparticles via surface functionalization of both the QDs and the YAG:Ce. Mixture of bromo-functionalized QDs and amino...

Glass-ceramic frits of various sizes composed of zinc aluminum calcium borosilicate (CaO−B2O3−SiO2−ZnO−Al2O3) were prepared by mechanical milling and subsequent size selection of the glass melt. Glass frits with mean particle sizes of 1.2 ± 0.9 μm, 2.9 ± 2.1 μm, and 4.8 ± 2.3 μm were successfully obtained using a two-step size selection process com...

Photoelectrochemical (PEC) water splitting devices rely on light-absorbers to absorb sunlight, and the photogenerated electrons and holes further react with water to generate hydrogen and oxygen. Fabricating light-absorbers on textured substrates offers alternative routes for optimizing their PEC performance. Textured substrates would greatly enhan...

We report an epitaxial growth of anatase TiO2 nanorods array (ANRs) on a niobium-doped TiO2 (NTO)/SrTiO3 (STO) single crystal substrate and its impact on charge transport and collection properties for photoelectrochemical (PEC) water splitting. The NTO film (∼6 at.% of Nb) with a thickness of ∼250 nm, was initially deposited as a transparent conduc...

For photoelectrochemical (PEC) hydrogen production, low charge transport efficiency of a photoelectrode is one of the key factors that largely limit the PEC performance enhancement. Here, we report tin-doped indium oxide (In2O3:Sn, ITO) nanowires array (NWs) based CdSe/CdS/TiO2 multi-shelled heterojunction photoelectrode. This multi-shelled one-dim...

We report a wet-chemical synthesis of yellow-emitting nanorod phosphors based on a Eu2+-doped Ba2Mg(PO4)2 (BMP:Eu) orthophosphate compound, and its enhanced optical and photoluminescence properties. A phase-pure BMP:Eu nanorod phosphor was prepared, for the first time, by using a two-step procedure: preparation of an amorphous nanorod precursor by...

For a hematite (α-Fe2O3) photoanode, multiple electron/hole recombination pathways occurring in the bulk, interfaces, and surfaces largely limit its low-bias performance (low photocurrent density at low-bias potential) for photoelectrochemical water splitting. Here, a facile and rapid three-step approach is reported to simultaneously reduce these r...