Article
Engineering, Electrical & Electronic
Reshmi Thekke Parayil, Santosh K. Gupta, Rohan Rohilla, Jyoti Prakash, Kathi Sudarshan, Manoj Mohapatra
Summary: Defect engineering is an efficient strategy to introduce different functionalities in materials, and this study synthesized Y2Zr2O7 by the gel combustion method and engineered defects through annealing. The resulting material exhibited dual-band bluish-green emission, with the color tunable from blue to green in the nano to bulk range. The bulk samples showed higher photoluminescence quantum yield and reduced surface defects compared to the nano samples. The materials also demonstrated potential as gas sensors for detecting VOCs, with excellent sensitivity and response and recovery time towards benzene.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jieru Bai, Yu Fu, Wenbo Kong, Bingrong Pan, Changkun Yuan, Shuqing Li, Jiyang Wang, Jun Zhang, Yuhan Sun
Summary: This study successfully altered the structural order of the catalysts by adjusting the Zr/Ce ratio, leading to different properties and compositions of surface oxygen species. Catalysts with more oxygen vacancies displayed better coke resistance. Among them, LNZ3C1 exhibited the highest activity, stability, and carbon deposition resistance.
Article
Chemistry, Physical
Shuai Gao, Runjie Wu, Mingming Sun, Ming Guo, Davida Briana DuBois, Shaowei Chen, Haodong Ji, Changzheng Wang, Qiang Wang
Summary: Development of effective technologies for artificial nitrogen fixation under mild conditions is crucial due to the energy consumption and carbon emission of the traditional Haber-Bosch process. This study synthesized Bi2Sn2O7 ultrasmall nanoparticles and found that the addition of sodium oleate can modulate their photocatalytic activity for nitrogen fixation. The optimized sample displayed superior photocatalytic performance with an NH3 production rate of 231 μmol g-1 h-1, attributed to its high specific surface area, abundant active sites for N2 adsorption, and extensive lattice oxygen vacancies. Furthermore, Bi species around the O2-site oxygen vacancies were identified to play a key role in N2 adsorption and activation, as supported by first principles calculations. These results highlight the significant potential of Bi2Sn2O7 nano-structures as high-performance catalysts for solar ammonia synthesis.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Pengfei Wang, Qingqing Cheng, Chenghui Mao, Wanyu Su, Lijun Yang, Guoliang Wang, Liangliang Zou, Yan Shi, Changfeng Yan, Zhiqing Zou, Hui Yang
Summary: In this study, a series of F-doped YRuOF catalysts were designed via low-temperature fluorination, showing significantly enhanced OER activity with an overpotential of -235 mV at 10 mA cm-2 compared to undoped pyrochlore (-296 mV). Additionally, the F-doped YRuOF catalyst demonstrated excellent OER stability.
JOURNAL OF POWER SOURCES
(2021)
Article
Chemistry, Physical
Eugenio F. de Souza, Lucia G. Appel
Summary: This study investigates the effects of oxygen vacancies and calcium doping on the surface properties of zirconium oxide using density functional theory. It is found that oxygen vacancies and the presence of calcium can significantly alter the surface properties and enhance the adsorption of CO2 on the surface.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Nathalie Vonrueti, Reshma Rao, Livia Giordano, Yang Shao-Horn, Ulrich Aschauer
Summary: According to conventional understanding, the oxygen evolution reaction on metal oxide surfaces involves multiple steps. However, recently proposed alternative reaction mechanisms with lower overpotentials often neglect non-electrochemical steps. Our study shows that exothermic non-electrochemical steps can also affect the thermodynamic overpotential, providing new insights into the reaction mechanisms.
Article
Nanoscience & Nanotechnology
Yi Chen, Fang Wang, Zeai Huang, Jiahao Chen, Chunqiu Han, Qilin Li, Yuehan Cao, Ying Zhou
Summary: The introduction of oxygen vacancies as dual-function centers enhances the oxidation reaction, making it possible to directly convert methane to methanol on two-dimensional BiOCl photocatalysts, improving the selectivity and yield of the reaction.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Environmental
Liang Yan, Bing Zhang, Zhonggang Liu, Junlu Zhu
Summary: In this study, Cu-doped CoOOH porous nanoplates were designed on carbon fiber paper to enhance the performance of oxygen evolution reaction. The synergistic effect of Cu doping with oxygen vacancy significantly modulated the electronic structure of the catalyst, improving the OER kinetics and activity. The optimized 3D self-supported Cu-CoOOH/CFP exhibited unprecedented OER activity and superior stability, showcasing its potential as an efficient electrocatalyst for water oxidation.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Physical
H. K. Mallick, Yajun Zhang, Jagabandhu Pradhan, M. P. K. Sahoo, A. K. Pattanaik
Summary: Traditionally, dopant concentration variation was believed to be the primary factor in activating and modulating the optical properties of semiconducting oxides, particularly the band gap. However, this work shows that secondary factors such as particle size and oxygen vacancy concentration also play a decisive role in determining the nature of the band gap. The study aims to resolve the longstanding controversy about the band gap in Al doped SnO2, demonstrating that the band gap increases with Al doping, among other findings.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Yanhui Sun, Jiawen Cui, Chuanxi Wang, Shouhang Fu, Shupeng Sun, Xue Wang
Summary: In this study, two-dimensional MoO3 nanoflakes with enriched oxygen vacancies were synthesized by hydrothermal method to improve the sensitivity of MoO3 sensors for hydrogen sulfide (H2S). The relationship between the oxygen vacancies concentration, the hydrothermal method temperature, and the solution concentration (ethanol) was investigated. The synthesized material MoO3_x-13021 with the highest oxygen vacancy concentration showed enhanced H2S-sensing properties compared to defect-free MoO3 sensors.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Applied
Hailong Liu, Biao Wu, Sikan Wu, Yongsheng Liu, Sorachon Yoriya, Chen Hu, Hai Zhang, Jiang Wu, Yang Ling, Ping He, Xuemei Qi
Summary: In this study, an efficient nickel ion-modified BiOIO3 nanosheet photocatalyst was synthesized for the removal of mercury from coal-fired flue gas. It was found that the doping of nickel ions can enhance the charge carrier separation and molecular oxygen activation by regulating the oxygen vacancy concentration of BiOIO3. The photocatalytic experiment showed that the mercury removal efficiency of the BiOIO3 catalyst with the optimum ratio of nickel doping reached 81.2%, higher than that of pure BiOIO3 (57.8%).
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Chemistry, Physical
Shida Liu, Haiyan Wang, Shuang Wang, Yiling Dai, Bing Liu, Yi Liu, Feixiong Dang, Kevin J. Smith, Xiaowa Nie, Shuandi Hou, Xinwen Guo
Summary: Transition metal oxides, particularly Co-based spinel oxides, have potential as alternatives to noble metal catalysts in oxidation reactions. In this study, NixCo3-xO4 catalysts were synthesized to investigate the influence of oxygen vacancies on catalyst activities and reaction mechanisms in ethane combustion. The activity was found to be correlated with the population and properties of O defects, with a higher number of defects resulting in increased activity. The shape-induced facet effect was also related to the amount of Ni incorporated into the octahedral sites of Co oxide. The findings from this study contribute to a better understanding of facet-dependent catalytic behavior and the design of high-performance catalysts.
Article
Engineering, Environmental
Ke Li, Yuanyuan Luo, Bo Liu, Hong Wang, Lei Gao, Guotao Duan
Summary: This study introduces oxygen vacancies into NiO to enhance its sensing performance towards H2S. Theoretical calculations and experimental results demonstrate that the oxygen vacancies can modify the electronic structure of NiO and reduce the reaction barriers of H2S species on the NiO surface, thereby improving the sensing performance. This research is significant for the design of oxygen vacancies in MOS sensors and the understanding of sensing mechanisms.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Xinxin Long, Chuanping Feng, Dahu Ding, Nan Chen, Shengjiong Yang, Huanyu Chen, Xinming Wang, Rongzhi Chen
Summary: In this study, a series of MOF-derived CoFe2O4 nanomaterials with tuned oxygen vacancies were prepared for peroxymonosulfate activation. The abundant surface oxygen vacancies and functional groups on CoFe2O4 were identified as active sites to boost catalytic activity. Different annealing temperatures influenced the stability, structural, and catalytic properties of the materials.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Engineering, Environmental
Meng Wang, Xiaowei Hong, Jianjun Chen, Junhua Li, Xiaoping Chen, Jinxing Mi, Zhiming Liu, Shangchao Xiong
Summary: MnOx-CeO2 catalysts prepared by either a two-step hydrothermal method or a deposition-precipitation method were evaluated for formaldehyde oxidation. The catalyst prepared by the hydrothermal method showed higher activity, which was attributed to the higher contents of Ce3+ and Mn4+ species and the generation of abundant chemisorbed oxygen species. DFT simulation confirmed the results and revealed the role of Mn loading on the CeO2 (1 1 0) plane.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Nanoscience & Nanotechnology
Venkata Sravani Vaddanam, Amesh Pamarthi, Somnath Sengupta, Madhusmita Sahoo, Santosh Kumar Gupta, Sreenivasulu Balija, Gopinadhanpillai Gopakumar, Cherukuri Venkata Siva Brahmananda Rao, Ammath Suresh, Shambhu Nath Jha, Sivaraman Nagarajan
Summary: A chemically, thermally, and radiation-stable Si/UiO-66-AO nanocrystalline MOF has been synthesized for the efficient removal of U-(VI) from acidic and aqueous media. The MOF demonstrated a high sorption capacity and rapid extraction ability, with a potential for U-(VI) extraction from seawater. The bonding between U-(VI) and Si/UiO-66-AO was confirmed, and the study provides a successful path for the development of acid-stable MOFs for commercial U-(VI) recovery applications.
ACS APPLIED NANO MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Santosh K. Gupta, Kathi Sudarshan, Brindaban Modak, Ruma Gupta
Summary: To reduce the reliance on rare earth and avoid supply risks associated with solid-state lighting and phosphor-converted LED technologies, a RE-free Zn2GeO4 microcrystalline phosphor was developed. The phosphor exhibited color tunable emissions from bluish-white to green and could convert X-ray into bluish-green light emission. The material showed potential for usage in solid-state lighting, display, and anticounterfeiting applications due to its dual persistent luminescence, tunability, and radioluminescence.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Article
Engineering, Environmental
Santosh Kumar Gupta, Brindaban Modak, Malini Abraham, Subrata Das, Ruma Gupta, K. G. Girija, Manoj Mohapatra, Kathi Sudarshan
Summary: This study presents a rare-earth free phosphor material for electric lighting, achieving high photoluminescence quantum yield and high-quality white light emission by manipulating defect density. The findings provide a promising solution to the issues of expensive rare earth doping and complex organic synthesis.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Annu Balhara, Santosh Kumar Gupta, Anil Krishna Debnath, Kathi Sudarshan
Summary: In this study, the luminescence properties of ZnAl2O4/Ho3+, Yb3+ phosphor were tailored by introducing Ho3+-Mn2+ energy transfer routes. The luminescence intensities of Ho3+ ions showed opposite behavior at 80K and 300K, indicating competition between temperature-sensitive decay pathways. The codoping of Mn2+ ions increased the absolute sensitivity by fourfold and allowed for color tunability from green to yellow to red, enabling rough temperature estimation by naked eyes.
Article
Chemistry, Physical
Annu Balhara, Santosh K. Gupta, Brindaban Modak, Sushri S. Nanda, Suryanarayan Dash, Kathi Sudarshan, Raghunath Acharya
Summary: In this study, remarkable enhancement in green and red upconversion emissions was achieved by co-doping Th4+ in YF3:Yb3+,Er3+ nanocrystalline particles. The UC luminescence in the NIR-II region was improved, while a strategy for luminescence intensity ratio (LIR) based thermometry involving thermally coupled stark sublevels was proposed. The high sensitivity values obtained from this approach make it promising for cryogenic temperature-sensing.
Article
Chemistry, Multidisciplinary
D. Das, R. Gupta, S. K. Gupta, A. K. Yadav, K. Sudarshan
Summary: The role of defects in multifunctional materials and defect engineering is intriguing. Oxygen vacancies in thoria samples were found to play a role in photoluminescence (PL) and oxygen reduction reaction (ORR) with the introduction of Eu3+ doping and removal upon codoping with Nb5+. The concentration of oxygen vacancies can be adjusted by the choice and concentration of aliovalent dopant and codopant to determine the desired functionality of the material.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Engineering, Chemical
Sanchita Ghosh, Sourav Patra, Apurav Guleria, Annu Balhara, Santosh Kumar Gupta, Avik Chakraborty, Sutapa Rakshit, Sanjay Vishwanath Thakare, Anil Krishna Debnath, Sudipta Chakraborty, Rubel Chakravarty
Summary: The synthesis of nanoradiopharmaceuticals, which combines nanotechnology and radiochemistry, has significantly enhanced the efficacy of cancer diagnostics and therapy. This study reports the production of a new positron emission tomography radionuclide, germanium-69, and its successful incorporation into synthesized nanoparticles. The in vivo stability and accumulation of these nanoparticles in liver and lymph nodes indicate their potential for more specific and individualized cancer care.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Inorganic & Nuclear
Sushil M. Patil, Ruchi Agrawal, Ruma Gupta, Santosh Kumar Gupta, Ayan Ghosh, Sumit Kumar, Kavitha Jayachandran, Tapan K. Ghanty
Summary: This study investigates the chemical aspects of europium ions in deep eutectic solvents (DES) through various experimental and computational methods. The findings reveal the chemical speciation, complexation behavior, photochemistry, and redox properties of europium ions in DES. The results contribute to the understanding and development of novel materials with enhanced luminescent and electrochemical properties.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Reshmi Thekke Parayil, Santosh K. Gupta, Manodip Pal, Arnab Dutta, Deepak Tyagi, Kathi Sudarshan, Manoj Mohapatra
Summary: Spinel materials have diverse applications in the energy sector. Modulating the Al/Ga ratio enhances their properties, allowing for multifunctional applications.
Article
Materials Science, Multidisciplinary
K. Sudarshan, Annu Balhara, Manish S. Kambli, Reshmi Thekke Parayil, Sushil M. Patil, Santosh K. Gupta
Summary: We report the synthesis of novel Cr3+ activated SrGa2O4 phosphors with broadband near infrared (NIR) emission. The results indicate that broad NIR emission can be achieved by doping Cr3+ at multiple sites with weak crystal field splitting. This research is important for further tuning NIR emission.
MATERIALS RESEARCH BULLETIN
(2024)
Article
Materials Science, Multidisciplinary
Reshmi Thekke Parayil, Santosh Kumar Gupta, Malini Abraham, Subrata Das, Shreyas S. Pitale, Kathi Sudarshan, Manoj Mohapatra
Summary: Deep red-emitting Y2Zr2O7:Eu3+ (YZOE) pyrochlore nanocrystals with very high color purity, excellent thermal stability, and a high photoluminescence quantum yield (over 88%) are synthesized for color tunable white LEDs and indoor plant growth.
MATERIALS ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Reshmi Thekke Parayil, Santosh K. Gupta, Madan Murari Upadhyay, Kathi Sudarshan, Manoj Mohapatra
Summary: Non-contact optical thermometers based on upconversion luminescence are in high demand in various fields. This study uses the emission response from non-thermally coupled levels for optical thermometry and achieves efficient upconversion and downconversion luminescence. ZnGa2O4:Er,Yb shows the most intense luminescence and excited state lifetime, and the introduction of gallium allows for color tunability. ZnGa2O4:Er,Yb exhibits good absolute sensitivity and relative sensitivity, making it suitable as an optical temperature sensor in the temperature range of 302-473 K.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Annu Balhara, Santosh K. Gupta, Nidhi Aggarwal, Swapnil Srivastava, Jiban Jyoti Panda, Sourav Patra, Avik Chakraborty, Sutapa Rakshit, Rubel Chakravarty
Summary: Na+ co-doped UCNPs show good cellular uptake, bio/cyto compatibility and anticancer efficacy, suggesting their potential for photothermal therapy and in vivo imaging for glioblastoma.
MATERIALS ADVANCES
(2023)
Article
Chemistry, Inorganic & Nuclear
Nitin Gumber, Muhammed Shafeeq, Santosh K. Gupta, Rohan Phatak, Uttam Kumar Goutam, Ravi Kumar, Rajesh V. Pai
Summary: In this study, uranium ions were successfully doped at the Ti site of Y2Ti2O7 pyrochlore, filling the gap area of actinide doping at the B site. The Y2Ti2O7 matrices showed good radiation and thermal stability, making them suitable for immobilization of high level waste. This work provides important information for selecting a suitable advanced ceramic matrix for waste immobilization.
DALTON TRANSACTIONS
(2023)
