Article
Chemistry, Physical
Samantha Prabath Ratnayake, Jiawen Ren, Billy J. Murdoch, Joel van Embden, Daniel E. Gomez, Chris F. McConville, Enrico Della Gaspera
Summary: This study demonstrates the fabrication of two-dimensional SnO2 nanosheet arrays and their application as electrodes for solar water oxidation. The nanosheets, when deposited on transparent electrodes, serve as substrates for the deposition of photoactive semiconductors, resulting in improved photoelectrochemical performance. The SnO2 nanosheets alone exhibit negligible PEC activity, suggesting that their enhanced performance is mainly due to their morphology and electronic effects. These findings provide a foundation for further research on efficient photoanode architectures for water splitting.
ACS APPLIED ENERGY MATERIALS
(2022)
Article
Chemistry, Applied
Jafar Hussain Shah, Anum Shahid Malik, Ahmed Mahmoud Idris, Saadia Rasheed, Hongxian Han, Can Li
Summary: In this study, particulate BFO and Mn-doped BiFeO3 were synthesized by the sol-gel method, demonstrating that Mn doping significantly enhances the oxygen evolution reaction (OER) activity under visible light irradiation. The bandgap of Mn-doped BFO could be reduced by varying the Mn doping amount, leading to improved absorption of visible light and decreased activation energy for water oxidation. Density functional theory (DFT) calculations suggested that surface Fe species are the active sites for water oxidation, with Mn doping leading to the lowest over-potential measured in this study. The synergistic effect of bandgap narrowing in Mn-doped BFO increases the photocatalytic water oxidation activity by inhibiting charge recombination and reducing activation energy.
CHINESE JOURNAL OF CATALYSIS
(2021)
Article
Environmental Sciences
Guoshuai Liu, Yukun Zhu, Qun Yan, Han Wang, Peng Wu, Yaoliang Shen, Yasmina Doekhi-Bennani
Summary: The removal of bromate has gained attention in drinking water treatment, and photocatalysis technology using monoclinic bismuth vanadate (BiVO4) single crystal as a visible photocatalyst has shown promising results with almost 100% removal efficiency. The spatial transfer of photo-generated electrons and holes, as well as high photocatalytic activity, contribute to the effective removal of bromate ions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Chemistry, Physical
Zhirun Xie, Hui Ling Tan, Hao Wu, Rose Amal, Jason Scott, Yun Hau Ng
Summary: It has been demonstrated that loading a cocatalyst onto a photocatalyst with exposed crystal facets can enhance photocatalytic activity. In this study, dual-faceted BiVO4 with different {010}/{110} exposure ratios was coupled with CoOx as a water oxidation cocatalyst. The location of cocatalyst deposition and the ratio of {010}/{110} facet exposure were found to determine the enhancement induced by the cocatalyst loading. Additionally, it was found that {010}-dominant BiVO4 benefitted more from the cocatalyst loading in both photocatalytic water oxidation and hydrogen peroxide generation reactions compared to {110}-dominant BiVO4.
MATERIALS TODAY ENERGY
(2022)
Letter
Chemistry, Physical
Alexei A. Belik
Summary: The aim of these comments is to draw attention to significant errors reported in the commented paper, in which the authors claimed the preparation of solid solutions Bi1-xHoxFeO3. However, the X-ray diffraction data revealed the absence of single-phase solid solutions.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Qian Dong, Fengling Yang, Feng Liang, Yan Zhang, Dehua Xia, Wei Zhao, Li Wu, Xueping Liu, Zhongfeng Jiang, Cheng Sun
Summary: Decahedral BiVO4 was successfully prepared at low temperature, forming BiVO4 nanosheet (S-BiVO4) through morphological changes in surfactant addition, which was then used to fabricate a series of Ag/S-BiVO4 plasmonic photocatalysts. Among them, Ag/4S-BiVO4 showed the highest photocatalytic performance, attributed to the SPR effect induced by silver nanoparticles.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Engineering, Environmental
Yoo Jae Jeong, Sung Won Hwang, Settasit Chaikasetsin, Hyun Soo Han, In Sun Cho
Summary: A novel dual-textured BiVO4 / Sb:SnO2 heterostructure was successfully synthesized as a photoanode for photoelectrochemical water splitting. The synthesized heterostructure exhibited a considerable enhancement in charge collection performance, resulting in a photocurrent density approximately four times higher than a single-textured heterostructure. This study provides new insights into the design of efficient photoelectrodes.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Astita Dubey, Chin Hon Keat, Vladimir V. Shvartsman, Kirill Yusenko, Marianela Escobar Castillo, Ana Guilherme Buzanich, Ulrich Hagemann, Sergey A. Kovalenko, Julia Staehler, Doru C. Lupascu
Summary: The ferroelectricity and narrow electronic bandgap of multivalent codoped Bismuth ferrite nanoparticles are utilized to enhance the photocatalytic activity. Doping with mono- and tri-valent cations increases the spontaneous polarization of the nanoparticles, leading to improved photocatalytic performance.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Engineering, Environmental
Ling-Ling Zheng, Lei Tian, Dengke Wang, Ying Chen, Qian-Qian Tang, Qiu-Ju Xing, Xiao-Zhen Liu, Dai-Zhen Liu, Jian-Ping Zou
Summary: In this study, we successfully synthesized BiVO4-X with tunable ratios of (010)/(1 1 0) co-exposing facet and investigated the effect of co-exposing facets on persulfate adsorption and activation. The results revealed the synergistic mechanism of BiVO4-X in efficiently degrading organic pollutants by simultaneous adsorption and activation of persulfate through the regulation of co-exposing facets. This work provides new insights into the precise control of crystal materials and their applications in persulfate activation systems.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Asanee Somdee, Surangkana Wannapop, Nuchanaporn Pijarn, Thiti Bovornratanaraks
Summary: Pure and doped p-n BiOCl/BiVO4 heterostructures with different levels of Ni were investigated for their application as photoanodes in photoelectrochemical cells. Various characterization techniques were used to study the properties of the materials, and density function theory calculations were employed to understand the physical mechanism of Ni substitution. The Ni-doped p-n BiOCl/BiVO4 heterostructure showed improved photocatalytic activity due to the additional surface state and increased charge carrier density.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Jia-Sheng Ma, Lu-Yin Lin
Summary: BiVO4 is a promising photocatalyst for water oxidation, doping heteroatoms and tungsten can enhance charge concentration and increase photocurrent density. The electrode with a Zn-doped bottom layer and W-doped top layer shows the highest photocurrent density and excellent long-term stability for water oxidation.
JOURNAL OF POWER SOURCES
(2021)
Article
Chemistry, Physical
Jin Wook Yang, Ik Jae Park, Sol A. Lee, Mi Gyoung Lee, Tae Hyung Lee, Hoonkee Park, Changyeon Kim, Jaemin Park, Jooho Moon, Jin Young Kim, Ho Won Jang
Summary: By designing a new photoanode with nanoporous BiVO4 and SnO2 nanorods focused on charge separation, high charge separation efficiency and photocurrent density are achieved. Coupled with NiFe as a co-catalyst for water oxidation and a perovskite/Si tandem solar cell, the system shows a high solar-to-hydrogen conversion efficiency for spontaneous solar hydrogen production.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Nanoscience & Nanotechnology
Mi Gyoung Lee, Jin Wook Yang, Hoonkee Park, Cheon Woo Moon, Dinsefa M. Andoshe, Jongseong Park, Chang-Ki Moon, Tae Hyung Lee, Kyoung Soon Choi, Woo Seok Cheon, Jang-Joo Kim, Ho Won Jang
Summary: In this study, a crystal facet engineering approach was used to control the band structures of titanium dioxide nanostructures as hole blocking layers for bismuth vanadate. The results showed that the BiVO4/TiO2 heterostructure with nanoflowers exhibited significantly higher photocurrent density compared to nanorods. The enhancement was attributed to reduced charge recombination due to the formation of type II band alignment between BiVO4 nanodots and TiO2 nanoflowers. This work not only provides new insights into the interplay between crystal facets and band structures but also advances the design of highly efficient photoelectrodes.
NANO-MICRO LETTERS
(2022)
Article
Chemistry, Physical
Luc Driencourt, Benjamin Gallinet, Catherine E. Housecroft, Soren Fricke, Edwin C. Constable
Summary: This study investigates the use of high refractive index nanoparticles to reduce reflection losses on photoanodes, thereby improving the performance of photoelectrochemical water-splitting. The results show that nanoparticle decoration on bismuth vanadate and hematite photoanodes leads to a 10% increase in photocurrent density and external quantum efficiency.
Article
Electrochemistry
Oluchi Nkwachukwu, Charles Muzenda, Kehinde D. Jayeola, Tsholofelo I. Sebokolodi, Dimpo S. Sipuka, Huizhong Wu, Babatunde A. Koiki, Minghua Zhou, Omotayo A. Arotiba
Summary: BFO/BVO heterojunction was used to enhance the photoelectrocatalytic degradation of ciprofloxacin. The heterojunction photoanode exhibited increased visible light harvesting, higher current density, lower charge transfer resistance, and reduced recombination rate. The BFO, BVO, and BFO/BVO photoanodes were characterized using various techniques and showed different levels of ciprofloxacin removal. The UPLC-MS data helped propose the degradation pathway and mechanism of the process.
ELECTROCHIMICA ACTA
(2023)
Article
Nanoscience & Nanotechnology
Min-Ju Choi, Taemin L. Kim, Kyoung Soon Choi, Woonbae Sohn, Tae Hyung Lee, Sol A. Lee, Hoonkee Park, Sang Yun Jeong, Jin Wook Yang, Sanghan Lee, Ho Won Jang
Summary: This study investigates the influence of the thickness of the overlayer on the photoelectrochemical activity of Fe2O3 film-deposited BiVO4/WO3 heterostructure. By adjusting the Fe2O3 layer thickness, the type of heterojunction can be changed, leading to improved photocurrent density.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Optics
Min Gyu Kwon, Cihyun Kim, Kyoung Eun Chang, Tae Jin Yoo, So-Young Kim, Hyeon Jun Hwang, Sanghan Lee, Byoung Hun Lee
Summary: In this paper, we improved the performance of a near-infrared graphene/germanium heterojunction photodetector by doping graphene with p-type chemical, which lowered the Fermi level and increased the Schottky barrier. The responsivity and detectivity were significantly improved, making it valuable for the development of graphene/semiconductor based photodetectors and near-infrared sensors.
Article
Chemistry, Physical
Jung-Woo Lee, Jongmin Lee, Jamin Ahn, Hongji Yoon, Hyunji An, Sang-Il Park, Hong-Seok Kim, Sehun Seo, Yong-Joo Doh, Wooyoung Lee, Sangwoo Ryu, Sanghan Lee
Summary: In this study, a conducting interface between LAO and thick homoepitaxial STO films was successfully fabricated using pulsed laser deposition. The careful optimization of laser ablation parameters led to stoichiometric 500 nm-thick STO films, and eventually, a crack-free, millimeter-sized STO membrane was achieved. These results are expected to enable the integration of complex oxide heterostructure membranes with various substrates.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Yoon Jung Lee, Kootak Hong, Kyeongho Na, Jiwoong Yang, Tae Hyung Lee, Byungsoo Kim, Chung Wung Bark, Jae Young Kim, Sung Hyuk Park, Sanghan Lee, Ho Won Jang
Summary: By controlling phase transitions in correlated materials, new functional properties can be achieved. This study demonstrates the control of a nonvolatile metal-insulator transition in vanadium dioxide (VO2) using a ferroelectric layer, showing enhanced coupling between correlated electrons and ferroelectric polarization. The research provides insights into interface properties, structural phase transitions, and design principles for heteroepitaxial correlated materials.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Eunhwa Kim, Sanghan Lee, Sangwoo Ryu
Summary: As interest in hydrogen energy grows, eco-friendly methods of producing hydrogen are being explored. CuBi2O4, a p-type semiconductor cathode material, has been investigated for its potential in photoelectrochemical hydrogen production. This study focused on the effect of sulfur doping on the bandgap and photoelectrochemical water reduction properties of CuBi2O4. The results showed that sulfur doping led to an expansion of the lattice volume, reduction in bandgap, and enhancement of photoelectrochemical current density. Further studies are expected to improve the surface coverage of sulfur-doped CuBi2O4 and optimize its performance as a photoelectrochemical cathode material.
KOREAN JOURNAL OF METALS AND MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jun-Cheol Park, Seungkyu Kim, Hojoong Choi, Yoonsung Jung, Inhyeok Oh, Jun Beom Hwang, Sanghan Lee
Summary: In this study, the WSe2/Bi2O2Se heterostructure was successfully fabricated for photodetector application using in situ pulsed laser deposition. The band alignment of the heterostructure was confirmed to be type II, which increased the photoresponse. The WSe2/Bi2O2Se photodetector exhibited an approximately 110% on/off ratio with a photoresponsivity of 0.96 mA/W even without lithography for its fabrication.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Energy & Fuels
Jaeyong Woo, Jongmin Lee, Jinsol Jun, Seungkyu Kim, Yoonsung Jung, Inhyeok Oh, Sanghan Lee
Summary: We examined the impact of stoichiometry on photovoltages and photocurrents in CuBi2O4 thin-film photocathodes by growing them under different oxygen partial pressures. The X-ray diffraction patterns confirmed crystalline phases in the CuBi2O4 thin films, and analysis revealed varying Cu/Bi ratios ranging from approximately 0.3 to 0.5. The slightly off-stoichiometric CuBi2O4 thin-film photocathode with a Cu/Bi ratio of approximately 0.44 exhibited the highest photocurrent density and significant stability.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2023)
Article
Chemistry, Physical
Hojoong Choi, Young Yun Kim, Sehun Seo, Yoonsung Jung, So-Min Yoo, Chan Su Moon, Nam Joong Jeon, Sanseong Lee, Kwanghee Lee, Francesca M. Toma, Jangwon Seo, Sanghan Lee
Summary: Reported is a high-efficiency organometal halide perovskite (OHP)-based photoanode with a rational design that suppresses undesired losses, such as non-radiative recombination of carriers and sluggish reaction kinetics. The rational design includes defect-passivated electron transport layers to suppress undesired recombination, and Fe-doped Ni3S2 with high catalytic activity to promote PEC water oxidation and suppress losses at OHP/electrolyte interface. The fabricated Fe-doped Ni3S2/Ni foil/OHP photoanodes achieved a remarkable applied bias photon-to-current efficiency of 12.79%, the highest among previously reported OHP-based photoanodes by suppressing undesired losses.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yoonsung Jung, Seungkyu Kim, Hojoong Choi, Yunseul Kim, Jun Beom Hwang, Donghyeon Lee, Yejoon Kim, Jun-Cheol Park, Dong-Yu Kim, Sanghan Lee
Summary: In this study, WO3 nanostructures decorated with Bi-MOFs were used as the photoanode to oxidize glycerol and simultaneously produce hydrogen, selectively converting glycerol to the high-value-added product glyceraldehyde. The Bi-MOF-decorated WO3 nanorods enhanced surface charge transfer and adsorption properties, resulting in improved photocurrent density and production rate. This study provides a practical approach for glycerol conversion to glyceraldehyde and demonstrates the potential of Bi-MOFs as a promising cocatalyst for PEC biomass valorization.
Article
Multidisciplinary Sciences
Nguyen Xuan Duong, Ji-Soo Jang, Min-Hyoung Jung, Jong-Seong Bae, Chang Won Ahn, Jong Sung Jin, Kyuwook Ihm, Gyehyeon Kim, So Yeon Lim, Jongmin Lee, Dang Duc Dung, Soonil Lee, Young -Min Kim, Sanghan Lee, Sang Mo Yang, Changhee Sohn, Ill Won Kim, Hu Young Jeong, Seung-Hyub Baek, Tae Heon Kim
Summary: Significant enhancements of low-frequency dielectric responses in oxygen-deficient oxide ceramics are demonstrated through specific treatments under humid environments. Ultrahigh dielectric permittivity is achieved by hydrogenation when Ni-substituted BaTiO3 ceramics are exposed to high humidity. Thermal annealing can restore the initial low polarizability state of the ceramics. The reversible control of dielectric relaxation characteristics in oxide ceramics allows for potential applications in highly efficient dielectric-based humidity sensors.
Proceedings Paper
Acoustics
Seonwoo Lee, Sunhee Kim, Minhwa Chung
Summary: This paper investigates the longitudinal phonetic inventories of vowels and consonants in Korean-speaking children with CI, comparing them to normal hearing children. The results show that the inventories of CI children are initially larger but become similar to those of normal hearing children after a year of stable hearing experience. These inventories can be used as references to assess speech development and guide habilitation goals.
Proceedings Paper
Computer Science, Artificial Intelligence
Seonwoo Lee, Sunhee Kim, Minhwa Chung
Summary: This paper introduces a speech corpus of 8 children with cochlear implants and proposes an enhanced metadata structure. The study determines key patient-related information for the corpus based on a meta-analysis and survey of speech and language pathologists. The results highlight important elements including age, implantation age, gender, and duration of CI use.
2022 25TH CONFERENCE OF THE ORIENTAL COCOSDA INTERNATIONAL COMMITTEE FOR THE CO-ORDINATION AND STANDARDISATION OF SPEECH DATABASES AND ASSESSMENT TECHNIQUES (O-COCOSDA 2022)
(2022)
Article
Chemistry, Physical
Seungkyu Kim, Eunui An, Inhyeok Oh, Jun Beom Hwang, Sehun Seo, Yoonsung Jung, Jun-Cheol Park, Hansol Choi, Chang Hyuck Choi, Sanghan Lee
Summary: A novel CeO2-decorated Ce-doped ZnO nanowire photoanode has been reported for efficient PEC glycerol oxidation and hydrogen production, with improved charge separation, light-harvesting, and glycerol adsorption. The Ce-doped ZnO array shows enhanced operation stability and doubled hydrogen evolution compared to a bare ZnO electrode.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Sehun Seo, Jong-Hoon Lee, Yejoon Kim, Seungkyu Kim, Chang Jae Yoon, Hojoong Choi, Sanseong Lee, Kwanghee Lee, Heejoo Kim, Sanghan Lee
Summary: Photoelectrochemical water splitting based on organic semiconductors is a promising method for sustainable hydrogen production, but it faces challenges of low efficiency and operational stability. This study developed a stable and efficient organic semiconductor-based photocathode module using metal encapsulation technique, achieving high photocurrent density and unprecedented stability.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Materials Science, Multidisciplinary
Dongwon Shin, Soon-Gil Jung, Sehun Seo, Jongmin Lee, Sanghan Lee, Jin Hee Kim, Jong-Soo Rhyee, Woo Seok Choi, Tuson Park
Summary: This study investigates the scaling behavior between Hall resistivity (pxy) and longitudinal resistivity (pxx) in FeSe0.7Te0.3 (FST) thin films, and explores the influence of different beta values on the vortex liquid state in FST thin films.
