Article
Materials Science, Multidisciplinary
Cuixia Cheng, Guosong Lai
Summary: Pure monoclinic Fe2(MoO4)3 nanoparticles were synthesized using a hydrothermal approach followed by calcination, and showed stable capacitance in supercapacitors after cycling, demonstrating potential application.
Article
Chemistry, Inorganic & Nuclear
Matthew Cheng, Yea-Shine Lee, Abishek K. Iyer, Daniel G. Chica, Eric K. Qian, Muhammad Arslan Shehzad, Roberto dos Reis, Mercouri G. Kanatzidis, Vinayak P. Dravid
Summary: Metal chalcophosphates of the M(2)P(2)Q(6) family can exhibit tunable magnetic ordering, with this study investigating the basic structural evolution and electronic properties of a mixed metal thiophosphate Fe2-xCoxP2S6 system. The alloying concentration was found to have a direct correlation with specific phonon modes and electronic structure, revealing nonlinear dependence on the metal alloying ratio. This work provides a fundamental structural framework for mixed metal thiophosphate systems, potentially aiding future studies on electronic and magnetic applications of this class of binary cation materials.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Lulu Jia, Hairong Xue, Fang Xian, Yoshiyuki Sugahara, Nobuyuki Sakai, Jingbo Nan, Yusuke Yamauchi, Takayoshi Sasaki, Renzhi Ma
Summary: A method for the synthesis of porous and positively charged iron oxyhydroxide nanosheets is reported, which involves the use of layered ferrous hydroxide as a starting precursor and undergoing topochemical oxidation, partial dehydrogenated reaction, and final delamination. As an electrocatalyst for electrochemical nitrogen reduction reaction (ENRR), the obtained nanosheets exhibit exceptional NH3 yield rate and Faradaic efficiency in a phosphate buffered saline (PBS) electrolyte. The study demonstrates the rational control on the electronic structure and morphology of porous iron oxyhydroxide nanosheets, expanding the development of efficient non-precious iron-based ENRR electrocatalysts.
Article
Engineering, Environmental
Chengwu Zhang, Chuipeng Kong, Paul G. Tratnyek, Chuanyu Qin
Summary: In this study, the relationship between the Fe2+/TPP ratio and the degradation mechanism of p-nitrophenol (PNP) in Fe2+/O-2 systems under neutral conditions was investigated. It was found that the Fe2+/TPP ratio regulated the degradation pathways of PNP, with different reactive oxygen species (ROS) involved at different ratios. By controlling the Fe2+/TPP ratio, the oxidation/reduction removal of pollutants can be selectively achieved.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Applied
R. F. Juca, J. M. Soares, V. A. Soares, D. S. Evaristo, F. G. S. Oliveira, I. F. Vasconcelos, G. D. Saraiva, N. S. Ferreira, M. A. Macedo
Summary: We report the magnetism of amorphous SiO2-Al2O3-CaO-MgO-Fe2O3-K2O-MnO: CA (CA-activated carbon) aluminosilicate glasses prepared by a fusion-quenching method. The presence of Fe2+ lattice modifier in the glass structures induces depolymerization, greatly affecting the magnetic transitions. Room temperature magnetization measurements reveal different magnetic behaviors, including speromagnetism, asperomagnetism, and weak ferromagnetism, in the CA-glasses. Analysis through Mo ssbauer spectroscopy at room temperature suggests that the change in valence from Fe3+-> Fe2+ triggers the asperomagnetism and weak ferromagnetism, due to Fe2+-O-Fe3+ superexchange coupling in short-range structures of the aluminosilicate glasses. A proposed model explains the different magnetic regimes in the aluminosilicate glass structures.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
F. F. H. Aragon, L. Villegas-Lelovsky, J. G. Parizaka, E. G. Zela, R. Bendezu, R. O. Gallegos, D. G. Pacheco-Salazar, S. W. da Silva, R. Cohen, L. C. C. M. Nagamine, J. A. H. Coaquira, P. C. Morais
Summary: Oxide-diluted magnetic semiconductors, specifically Fe-doped ZnO nanoparticles, were synthesized and investigated to understand the effect of Fe doping on their structural, vibrational, optical, hyperfine, and magnetic properties. The results showed that increasing Fe content led to a decrease in crystallite size. XRD analysis revealed different solid solution phases for low and high Fe content. Elliot's theory was used to determine band gap energy and exciton binding energy. FTIR analysis indicated changes in Zn-O bond length and intensity ratio of O-H and Zn-O modes with Fe content. Mossbauer spectra and magnetic measurements showed stabilization of iron ions and the presence of antiferromagnetic interactions.
MATERIALS ADVANCES
(2023)
Article
Green & Sustainable Science & Technology
ChungHyok Jo, Xiangru Song, Minghua Zhou
Summary: The addition of sustained-release iron ions prepared by polymer encapsulation to the anodic chamber of bioelectro-Fenton improved the efficiency of pollutant degradation. Adjusting the release of Fe3+ and maintaining a stable Fe2+ production promoted the iron cycle and increased the effectiveness of bioelectro-Fenton. The presence of the microbial electron transport enzymes contributed to higher Fe2+ production and improved pollutant removal.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Chemistry, Physical
Jiaxin Yao, Yitong Zhou, Jun-Min Yan, Qing Jiang
Summary: This study proposes a method to improve the electrocatalysis process in nitrogen reduction reactions, and demonstrates that Au/Fe-2(MoO4)(3) exhibits outstanding performance under ambient conditions.
ADVANCED ENERGY MATERIALS
(2021)
Article
Engineering, Environmental
Yi-bo Hu, Ting Du, Lihang Ma, Xuening Feng, Yujie Xie, Xiaoyao Fan, Baoling Yuan, Xiao-yan Li
Summary: The effect of oxygen on the removal of Cd(II) by nanoscale zero-valent iron (NZVI) has been investigated. It was found that Cd(II) adsorbed on the surface of NZVI can be reduced to Cd(0) under anaerobic conditions. However, the presence of oxygen significantly decreases the Cd(II) removal efficiency and inhibits Cd(II) reduction due to the thickened surface gamma-FeOOH layer. Moreover, oxygen intrusion corrodes Cd(0) and leads to the leaching of Cd(II) ions.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Engineering, Environmental
Kaiyao Hu, Wenxuan Li, Hao Mu, Shuang Ren, Hongjuan Zhu, Kexin Zeng, Bo Wang, Jinming Liang, Qi Zhang, Lili Yang, Wei Zhao, Juqiang Xiao
Summary: In this study, s-Fe0 was used as a carrier filler in an SBR reactor to remove the passivation layer on its surface by anaerobic means. The results showed that s-Fe0 is a promising material for nitrogen and phosphorus removal, and anaerobic treatment can effectively alleviate the passivation of s-Fe0.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Chemistry, Applied
Anuj Kumar, Ying Zhang, Yin Jia, Wen Liu, Xiaoming Sun
Summary: In this study, the effect of electron-donating substituents on the Fe3+/Fe2+ redox potential and ORR activity of FePc@CNTs was evaluated, with electron-donating groups leading to a cathodic shift in the redox potential. The ORR activity was found to decrease in the order of -H > -t-Bu > -NH2 based on the substitution of FePc.
CHINESE JOURNAL OF CATALYSIS
(2021)
Article
Environmental Sciences
Yue Gao, Yanan Xue, Jing Ji, Kai Zhen, Xuejiao Tang, Peng Zhang, Cuiping Wang, Hongwen Sun
Summary: The remediation of industrial site soil using Fe2+ chelated with sodium citrate activated persulfate oxidation (PS/Fe2+/SC) was investigated. The study found that the maximum removal rates of sigma 16 PAHs in Nanjing site soil (NJS) and Hefei site soil (HFS) were 73.6% and 85.8% after the second-stage oxidation, respectively. However, the efficiency of PAHs degradation did not increase in the later oxidation stages due to the presence of high crystalline Fe mineral phases in both NJS and HFS, which hindered the Fe2+/Fe3+ recycle and inhibited the production of reactive oxygen species during the remediation process.
Article
Engineering, Environmental
Nicole C. Rockey, Yun Shen, Sarah-Jane Haig, Madeleine Wax, James Yonts, Krista R. Wigginton, Lutgarde Raskin, Terese M. Olson
Summary: The switch in drinking water source in Flint from Detroit to Flint River water without corrosion control led to the leaching of lead and other metals. Replacement of service lines had significant short-term and long-term benefits by reducing lead concentrations in drinking water, but short-term advantages were less apparent in sites with prior lead seeding.
ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY
(2021)
Article
Electrochemistry
Jingtao Wang, Zhengyang Xu, Jia Liu, Haodi Wei
Summary: The study focused on the use of a novel C6H5K3O7 solution in electrochemical machining to reduce stray corrosion on non-machined surfaces of Inconel 718 superalloy blades. The results indicated that the C6H5K3O7 solution led to a lower breakdown potential and looser passive film structure compared to the NaNO3 solution, effectively suppressing stray corrosion. In-situ observations and models confirmed that a stable gaseous layer induced by C6H5K3O7 solution insulated the anode surface and reduced zones of stray corrosion, demonstrating the feasibility of using C6H5K3O7 as an electrolyte for stray-current attack reduction.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2022)
Article
Engineering, Environmental
Da Ouyang, Ronghao Wu, Zhaojun Xu, Xiaomin Zhu, Yimin Cai, Ruihuan Chen, Changyin Zhu, Damia Barcelo, Haibo Zhang
Summary: In this study, biochar-supported molybdenum dioxide was used as a co-catalyst to enhance the activation ability of Fe3+ on persulfate for the degradation of Bisphenol A. The results showed that over 96% of BPA was removed within 60 minutes, and the degradation efficiency only slightly decreased after four reuses of the co-catalyst. The study also revealed that biochar supports the adsorption of Fe3+ on the MoO2 surface and promotes electron transfer. This work provides a new insight for improving the degradation of organic contaminants in wastewater.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Shinbi Lee, Yoojin Lee, Wonyong Choi
Summary: Nitrate (NO3-) and nitrite (NO2-) are common water pollutants and need to be controlled for water quality. A method using Pd-loaded TiO2 (Pd/TiO2) in an aqueous suspension has been developed for the conversion of nitrite to nitrate. The presence of aquatic pollutants such as arsenite (As (III)) or 4-chlorophenol (4-CP) can change the main photoconversion product from nitrate to N-2 and enhance the durability of Pd/TiO2. This process can be a viable treatment option for nitrite-contaminated water with various aquatic pollutants.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Cong-Xue Liu, Dong-Lai Pan, Younggyu Seo, Seungjae Park, Jing -Lan Kan, Jin Young Koo, Wonyong Choi, Eunsung Lee
Summary: The first examples of phenanthroimidazole-based covalent organic frameworks (COFs), PIm-COF1 and PIm-COF2, were reported in this study, showing substantial optical properties. PIm-COF2 exhibited an average hydrogen evolution rate of 7417.5 μmolg-1h-1, which was 14 times higher than that of PIm-COF1 (528.5 μmolg-1h-1). This can be attributed to the strong donor-acceptor effect of PIm-COF2 and the continuous separation and transfer of the photoexcited electron-hole pair from the phenanthro[9,10-d]imidazole moiety, which was confirmed by time-dependent density functional theory and excitation state analysis.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Bupmo Kim, Dayoung Kwon, Jin-Ook Baeg, P. Muthu Austeria, Geun Ho Gu, Jeong-Hyeon Lee, Jeehun Jeong, Wooyul Kim, Wonyong Choi
Summary: A new single-atom dual-atom-site catalyst has been developed to significantly promote the production of formaldehyde through the four-electron transfer pathway of *OCHO. The neighboring Sn(II)-Cu(I) dual-atom sites stabilize the intermediates for formaldehyde production, and the adsorbed *HCHO intermediate is detected by in situ Fourier transform infrared spectroscopy. This study provides a unique example of controlling the selectivity of multi-electron transfer mechanisms for CO2 photoconversion using a heteronuclear dual-atom-site catalyst to generate an uncommon product (formaldehyde) from CO2 reduction.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Soumen Dutta, Akshay Gurumoorthi, Shinbi Lee, Sun Woo Jang, Nitee Kumari, Yu-Rim Hong, Wonyong Choi, Chang Yun Son, In Su Lee
Summary: By utilizing few-nm-thin two-dimensional nanocrystals of MOF-5, a crystal lattice-guided wet-chemical etching process has been developed to regulate attractive pore patterns on the MOF surface. The optimized etching process produces size-tunable fractal-pores that enhance the activity and stability of the supported catalyst in photoelectrochemical CO2-to-CO reduction. The long-range fractal opening in the 2D MOF support structure facilitates cross-interface charge transportation and exposure of immobilized Re-I-catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Environmental
Juanshan Du, Kitae Kim, Seungwoo Son, Donglai Pan, Sunghwan Kim, Wonyong Choi
Summary: In this study, we investigated the oxidation of iodide by different types of manganese dioxides (??- MnO2, ??-MnO2, and ??-MnO2) in frozen and aqueous solutions. The results show that in frozen environments, a heterogeneous reaction produces reactive iodine (RI), which gradually transforms into iodate or iodide upon thawing depending on the types of manganese dioxides. Additionally, iodination of fulvic acid by I???/MnO2 was observed in both aqueous and frozen solutions, with higher yields of organoiodine compounds (OICs) obtained in frozen solution.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Shi Nee Lou, Vinod K. Paidi, Kug-Seung Lee, Hyunwoong Park, Wonyong Choi
Summary: Researchers have developed a p-type NiO nanoplate thin film photocathode with rich Ni vacancies, which can harvest sunlight and store electrical energy in a single material. The band gap excitation of NiO creates surface adsorption of hydroxide anions and storage of photogenerated holes, forming NiOOH. The stored energy in NiOOH can be discharged to provide a sustainable current in the absence of light. The energy storage capacities of NiO depend on the electrolyte pH and the applied bias.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Bupmo Kim, Chang Won Yoon, Wooyul Kim, Wonyong Choi
Summary: In this study, the molecular-level reaction mechanism of nanoporous gold electrodes for the conversion of carbon dioxide to carbon monoxide was investigated using surface-enhanced infrared absorption spectroscopy (SEIRAS). It was found that the nanoporous gold electrodes promoted the formation of linear CO intermediate and suppressed the formation of bridging CO intermediate. The study also revealed a high local pH and slow diffusion kinetics of local CO3 (2-) at specific reaction potentials. These findings provide insights into the electrochemical kinetics and mechanisms occurring in the electric double layers, highlighting the potential for designing efficient electrocatalysts for CO2 reduction.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Yubao Zhao, Jingyu Gao, Zhenchun Yang, Lina Li, Jiahao Cui, Peng Zhang, Chun Hu, Caozheng Diao, Wonyong Choi
Summary: By anchoring cationic methyl viologen (MV) on polymeric carbon nitride (CN) photocatalyst with an anionic moiety, an ionic link is generated, resulting in an internal local electric field in the organic photocatalyst framework, which greatly enhances exciton dissociation. This study demonstrates an unprecedentedly efficient photocatalyst for the photoproduction of hydrogen peroxide (H2O2), and provides a mechanistic rationale for its remarkable catalytic performance.
Editorial Material
Chemistry, Physical
Kangwoo Cho, Wonyong Choi, Detlef Bahnemann
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Editorial Material
Chemistry, Physical
Kangwoo Cho, Wonyong Choi, Detlef Bahnemann
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Multidisciplinary Sciences
Yuyang Kang, Zhenao Gu, Baiwen Ma, Wei Zhang, Jingqiu Sun, Xiaoyang Huang, Chengzhi Hu, Wonyong Choi, Jiuhui Qu
Summary: Electrocatalytic oxidation can be enhanced by reducing pore size, leading to improved reaction kinetics and electron transfer pathways. This study provides insights for the design of cost-effective electrochemical platforms.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Yi Hu, Juanshan Du, Gun-hee Moon, Wonyong Choi
Summary: This study investigates the role of direct hole transfer in the oxidation of aromatic compounds in the photocatalytic process. The findings suggest that the extraction of an electron from substituted aromatic compounds by holes is the rate-determining step in the overall photocatalytic oxidation process.
Article
Engineering, Environmental
Juanshan Du, Yi Hu, Kitae Kim, Wonyong Choi
Summary: This study found that the photosensitized reduction of iodate by fulvic acid is enhanced in frozen solution. The process involves the production of iodide, reactive iodine, and organoiodine compounds. The reduction increases with decreasing pH and increasing fulvic acid concentration, and is enhanced by coexisting iodide or chloride ions.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Tae Hwa Jeon, Cheolwoo Park, Unseock Kang, Gun-hee Moon, Wooyul Kim, Hyunwoong Park, Wonyong Choi
Summary: By depositing CN and metal-incorporated CN films on hematite, the photoelectrochemical activity and photocurrent density of hematite-based photoanodes can be significantly improved, along with enhanced Faradaic efficiency for oxygen evolution.
APPLIED CATALYSIS B-ENVIRONMENT AND ENERGY
(2024)
Article
Chemistry, Physical
Chuhyung Kim, Soonhyun Kim, Yiseul Park, Wonyong Choi
Summary: This study demonstrates the use of Fe2O3/CNF as a heterogeneous Fenton-like catalyst for simultaneous removal of various organic and inorganic contaminants without the need for external energy input and chemical reagents. The Fe2O3/CNF exhibits notable activities for spontaneous oxidative degradation and reductive transformation in ambient solution, with a synergistic effect for removing dual contaminants.
APPLIED CATALYSIS B-ENVIRONMENT AND ENERGY
(2024)
