Article
Chemistry, Physical
Vaishali Sharma, Basant Roondhe, Sumit Saxena, Alok Shukla
Summary: Rapid advances in catalysis require microscopic understanding, but experimental insights are limited. Density functional theory can guide experimental searches for catalysts. Graphene quantum dots show potential as efficient catalysts, and their properties can be enhanced through doping and functionalization.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Zhiyuan Wei, Zihao Guan, Fang Liu, Yanyan Xue, Naying Shan, Yang Zhao, Lulu Fu, Zhipeng Huang, Jun Xu, Mark G. Humphrey, Chi Zhang
Summary: This study constructed covalently linked nanocomposites composed of graphene oxide (GO) and MoS2, WS2 quantum dots (QDs). These nanocomposites demonstrated significant fluorescence quenching and superior two-photon absorption (TPA) responses, indicating their promising potential in optical limiting applications and ultrafast photonic devices.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Jianguang Feng, Qian Guo, Na Song, Haiying Liu, Hongzhou Dong, Yingjie Chen, Liyan Yu, Lifeng Dong
Summary: Heteroatom co-doping is an effective way to tailor electronic structures of graphene quantum dots with synergistic effects and desirable properties. Different N-doping configurations can endow GQDs with a wide spectrum of new optical properties and electronic structures, providing valuable insights for understanding absorption mechanisms and electronic properties of heteroatom co-doped GQDs as well as achieving new applications with well-defined and desired properties.
DIAMOND AND RELATED MATERIALS
(2021)
Article
Optics
Nur Afifah Ahmad Nazri, Nur Hidayah Azeman, Mohd Hafiz Abu Bakar, Nadhratun Naiim Mobarak, Athiyah Sakinah Masran, Ahmad Rifqi Md Zain, Mohd Adzir Mahdi, Adhitya Gandaryus Saputro, Triati Dewi Kencana Wung, Yunhan Luo, Ahmad Ashrif A. Bakar
Summary: This report introduces a microfiber chlorophyll sensor based on polymeric amine functionalized carbon quantum dots, which can detect chlorophyll with high sensitivity and low detection limit. The sensor utilizes surface plasmon resonance technique and shows promising potential for real-time environmental monitoring applications.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Chemistry, Applied
Peng Cui, Yuan Xue
Summary: In this study, the effects of carboxylation on the optoelectronic properties of GQD@cellulose nanocomposites were investigated. The results show that hexagonal GQDs with armchair edges exhibit improved photoelectric performance, and carboxylation stabilizes the energy levels of triangular GQDs with armchair edges, facilitating hole transfer to cellulose upon photoexcitation.
CARBOHYDRATE POLYMERS
(2023)
Article
Nanoscience & Nanotechnology
Mohamed A. Abdelati, Mohamed M. Fadlallah, Yosr E. E-D Gamal, Ahmed A. Maarouf
Summary: This study investigated the structural stabilities and optical properties of graphene quantum dots (GQDs) and holey GQDs with different sizes, edge terminations, and pore passivations using density functional theory (DFT) and time dependent DFT. Results showed that the optical spectra of GQDs primarily depend on their size, while pore passivation has the biggest effect on the absorption spectra of holey GQDs. These findings can be applied in the development of promising materials for various applications, such as biological sensors and optoelectronic devices.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Biochemistry & Molecular Biology
Parvathy Nancy, Nithin Joy, Sivakumaran Valluvadasan, Reji Philip, Sabu Thomas, Rodolphe Antoine, Nandakumar Kalarikkal
Summary: This article presents a one pot, facile and ecofriendly synthesis approach for fabricating graphene quantum dots (GQDs) by pulsed laser irradiation of an organic solvent. The obtained GQDs exhibit fluorescence and nonlinear optical absorption, showing potential applications in optoelectronics and light-harvesting devices.
Article
Chemistry, Physical
Na Hou, Fang-Yue Du, Ran Feng, Hai-Shun Wu
Summary: Doping alkali and alkaline-earth metal atoms can efficiently reduce the energy gap of black phosphorus quantum dots and increase the second hyperpolarizability values. Among them, the alkali-doped complexes have larger hyperpolarizability values compared to the alkaline-earth-doped complexes, and doping heavier metal atoms on larger BPQDs can achieve the highest hyperpolarizability values.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Engineering, Electrical & Electronic
Zhuang Zhao, Xuechao Li, Yiming Duan, Ceng Chang, Liangcheng Zhang
Summary: This theoretical study investigates the changes in the optical rectification coefficient in tuned quantum dots under the influence of external factors. It is found that the resonance peak of the OR coefficient can shift towards higher or lower energies under different constraint parameters, resulting in a red shift or blue shift.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Multidisciplinary Sciences
Celia L. Gomez, O. Zaca Moran, M. Rojas-Lopez, C. Moran-Raya, P. Zaca-Moran
Summary: This study reports the nonlinear optical response of graphene oxide quantum dots (GOQDs) produced through the carbonization and exfoliation of electrospun polyacrylonitrile (PAN) fibers. The characterization of electrospun and carbonized fibers was done using SEM and XPS. The GOQDs obtained were characterized using PL, UV-Vis, Raman spectroscopy, and HRTEM. The nonlinear characterization showed a saturable absorption behavior, indicating potential applications in optical switching.
Article
Physics, Multidisciplinary
Priya Rani, Ranjeet Dalal, Sunita Srivastava
Summary: Theoretically, excellent non-toxic fluorescent graphene quantum dots (GQDs) with near-infrared (NIR) fluorescence have been achieved for bio-imaging and sensing applications. Cheap and non-toxic sulfur and its group elements were used for doping. The effect of doping position on energy band gap, absorption, and fluorescence properties was studied. The highest quantum yield (QY) of 26% in NIR was obtained for sulfur-doped GQDs (S-GQD: C52S2H18), which is higher than the previous 7% and the first reported high QY in NIR.
Review
Chemistry, Inorganic & Nuclear
Pavithra V. Ravi, Vinodhini Subramaniyam, Neha Saravanakumar, Ajay Pattabiraman, Moorthi Pichumani
Summary: Graphene Quantum Dots (GQDs) are a breakthrough material with optoelectronic properties, widely used in various applications such as agriculture, biomedical, sensors, energy storage, water desalination, and environmental remediation. Functionalization of GQDs enhances their biocompatibility, making them suitable for use in biotechnology, immunology, biochemistry, and diagnostics. The nanoscale morphology of GQDs can alter device structure and simplify functionality, leading to potential applications in wearable and portable sensors. This review explores functionalization strategies of GQDs and their applications in different fields.
COORDINATION CHEMISTRY REVIEWS
(2023)
Article
Chemistry, Physical
Farman Ullah, Robabeh Bashiri, Norani Muti Mohamed, Adriana Zaleska-Medynska, Chong Fai Kait, Usman Ghani, Muhammad Umair Shahid, Mohamed Shuaib Mohamed Saheed
Summary: The characteristics of the interface between one-dimensional titanium dioxide (1D TiO2) photoanodes and graphene quantum dots (GQDs) were studied using both density functional theory (DFT) and experimental methods. The results showed that the interface structure significantly enhanced the photocatalytic hydrogen production efficiency, with a five-fold increase in hydrogen production rate. Additionally, a mechanism for photogenerated electron transfer and energy-band-matching at the hybrid interface was proposed.
APPLIED SURFACE SCIENCE
(2022)
Article
Multidisciplinary Sciences
Xiang Zhang, Yu Gu, Yun Zhang, Guo-Yin Yu, Zhi-Peng Liao, Hui-Fang Wu, Chuan-Guo Shi
Summary: In this study, dual-emissive N-GOQDs fluorescent probes were successfully developed for monitoring intracellular pH. These probes possess bright fluorescence, high stability, and good biocompatibility.
Article
Chemistry, Physical
Sifa Kir, Ilyas Dehri, Yunus Onal, Ramazan Esen, Canan Akmil Basar
Summary: Graphene quantum dots (GQDs), a carbon allotrope, have gained widespread industrial application due to their unique optical and electrical properties. In this study, GQDs were obtained from materials such as graphite, glycine, alginate, and glucose. The elemental and optical properties of the GQDs were analyzed using various techniques, including XRD, SEM, Elemental Analysis, Fluorescence Spectrometry, and UV-Visible Spectroscopy. The results confirmed that the material obtained from molasses was indeed GQDs.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Debolina Paul, Harkishan Dua, Utpal Sarkar
FRONTIERS IN CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Debolina Paul, Jyotirmoy Deb, Utpal Sarkar
Article
Chemistry, Multidisciplinary
Sukhwinder Singh, Jyotirmoy Deb, Utpal Sarkar, Sandeep Sharma
Summary: The research team developed a MoS2/MoO3 composite with enhanced surface properties using a two-step approach, which exhibited superior sensing characteristics as a gas sensor in detecting NH3 under extreme working conditions. The synergistic effect of heterostructure formation between the base materials contributed to the selective response of the composite towards NH3 gas in humid environments.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Jyotirmoy Deb, Rajkumar Mondal, Utpal Sarkar, Hatef Sadeghi
Summary: This study investigates the thermoelectric properties of BN-doped graphynes through first-principles calculations, showing high Seebeck coefficients and low thermal conductance, indicating their potential for thermoelectric applications. Among the studied systems, the graphyne-like BN sheet demonstrates the highest electrical conductance and lowest thermal conductance, with a maximum ZT value of about 6 at room temperature.
Article
Nanoscience & Nanotechnology
Sukhwinder Singh, Jyotirmoy Deb, Jatinder Vir Singh, Utpal Sarkar, Sandeep Sharma
Summary: By using a heterostructure-based design with a MoSe2/SnO2 composite, sensitive and selective detection of ethyl mercaptan at room temperature has been achieved. The composite shows detection capability for ethyl mercaptan over a wider range of relative humidity and exhibits adsorption selectivity towards ethyl mercaptan compared to other analytes. The device also maintains stable response even at extreme humidity levels.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Biochemical Research Methods
Rajkumar Mondal, N. Bedamani Singh, Jyotirmoy Deb, Swarnakamal Mukherjee, Utpal Sarkar
Summary: This study examines the effect of strain on the electronic properties of 2D BP sheets using DFT, finding that changes in strain can significantly impact the band gap and electrical characteristics, particularly favoring the zigzag sheet for thermoelectric applications.
JOURNAL OF MOLECULAR GRAPHICS & MODELLING
(2022)
Article
Nanoscience & Nanotechnology
Sukhwinder Singh, Jyotirmoy Deb, Suresh Kumar, Utpal Sarkar, Sandeep Sharma
Summary: This study demonstrates a chemiresistor sensor based on a composite of MoSe2 and multiwalled carbon nanotubes for the detection of DMF in the environment. Compared to a standalone MoSe2 sensor, the composite-based sensor shows improved sensitivity, selectivity, and response and recovery times, as well as consistent response over a wider range of relative humidities.
ACS APPLIED NANO MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Jyotirmoy Deb, Rajeev Ahuja, Utpal Sarkar
Summary: In this study, the potential of pentagraphyne (PG-yne) as an anode material for Li/Na ion batteries was explored using density functional theory. It was found that PG-yne has a high theoretical capacitance and low diffusion barriers, making it a promising candidate for anode materials. The fast diffusion of Li/Na ions over the PG-yne surface further supports its applicability.
ACS APPLIED NANO MATERIALS
(2022)
Article
Physics, Condensed Matter
Jyotirmoy Deb, Rajkumar Mondal, Swarnakamal Mukherjee, Utpal Sarkar
Summary: In this study, the thermoelectric property of a two-dimensional pentagraphene sheet was investigated. It was found that pentagraphene has a higher Seebeck coefficient compared to conventional thermoelectric materials, confirming its potential as a thermoelectric device. Interestingly, the Seebeck coefficient decreases with temperature, while the electrical and thermal conductance increase, leading to the significant thermoelectric performance of pentagraphene at higher temperatures.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Jyotirmoy Deb, Ajit Kundu, Nandini Garg, Utpal Sarkar, Brahmananda Chakraborty
Summary: Novel two-dimensional carbon allotropes, pristine graphyne and Cu-doped graphyne, have been proposed as potential nanocarriers for cisplatin anticancer drug delivery based on theoretical demonstrations. Binding energy calculation shows that both pristine graphyne (-0.550 eV) and Cu-decorated graphyne (-0.750 eV) fall within the physisorption range, making them suitable candidates for drug delivery. A charge transfer of 0.012 e from Cu-decorated graphyne results in charge depletion in the Cu-doped graphyne system, mainly attributed to the loss of Cu (0.012 e). The reevaluation of binding energy under biological environment (acidic conditions) indicates a decrease (-0.012 eV) and low recovery time, suggesting successful drug release. Ab initio molecular dynamics simulation confirms the stability of Cu-doped graphyne at 300 K and its potential as a nanocarrier. Notably, desorption temperature is slightly higher than body temperature and comes closer under acidic environment, indicating successful absorption within the human body. Our theoretical predictions will inspire experimentalists in designing graphyne-based drug delivery systems.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Purashri Basyach, Jyotirmoy Deb, Saddam Sk, Ujjwal Pal, Madhulekha Gogoi, G. Narahari Sastry, Lakshi Saikia
Summary: In this study, a low-cost, environmentally friendly and suitable semiconductor-based heterogeneous photocatalyst was developed for efficient hydrogen evolution through photocatalytic water splitting. The Ni-CuWO4/g-C3N4 nanocrystals demonstrated an enhanced photocatalytic efficacy for H2 generation compared to pure g-C3N4 and Ni-CuWO4. The significant improvement in photocatalytic behavior was attributed to the large surface area, limited band gap energy, and enhanced light harvesting capability of the semiconductor composite. Density functional theory (DFT) calculations further confirmed the potential of the Ni-CuWO4/g-C3N4 composite as a visible-light-driven photocatalyst.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Energy & Fuels
Harkishan Dua, Jyotirmoy Deb, Utpal Sarkar
Summary: This study proposes a magnesium ion rechargeable battery with a twin-graphene based anode material as a feasible alternative to lithium-ion rechargeable batteries. The stability and capacity of magnesium ion adsorption on the substrate are investigated, and the trigonal sites are found to be the most stable. The twin-graphene supercell can accommodate up to 8 Mg ions, resulting in a high theoretical capacitance of 496.2mAh/g. The thermodynamic stability of the Mg adsorbed anode material is confirmed in both single and fully accommodated systems. Nudged elastic band calculations reveal a low diffusion barrier for the movement of Mg ions, indicating higher diffusivity and faster charging rates in the system, making twin-graphene a suitable material for Mg-ion batteries (MIB).
Article
Chemistry, Physical
Jyotirmoy Deb, Harkishan Dua, Utpal Sarkar
Summary: A 'twin-graphene' bilayer-based nanoscale capacitor and nanoscale dielectric capacitor were designed using density functional theory approach, showing significant effects on electronic properties based on different stacking modes. The AB stacking mode was found to be the most stable with a band gap of 0.553 eV. The predicted energy and charge-storage capacities were higher than those of other two-dimensional carbon allotropes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Sukhwinder Singh, Jyotirmoy Deb, Utpal Sarkar, Sandeep Sharma
Summary: This article presents a highly sensitive and selective chemiresistive ammonia sensor based on a p-MoS2/n-WO3 heterojunction, showing enhanced performance compared to individual MoS2 and WO3 sensors. The device demonstrates excellent response-recovery features and selectivity towards ammonia, with the capability to detect ammonia down to 1 ppm. The experimental results are further supported by density functional theory (DFT) simulation to understand the sensing mechanism and charge transfer dynamics.
ACS APPLIED NANO MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Harkishan Dua, Jyotirmoy Deb, Debolina Paul, Utpal Sarkar
Summary: The twin-graphene structure shows promising potential as an anode material in sodium-ion rechargeable batteries due to its high theoretical capacitance and good diffusivity.
ACS APPLIED NANO MATERIALS
(2021)
