Ni, Co, Zn, and Cu metal-organic framework-based nanomaterials for electrochemical reduction of CO₂: A review

• Ha Huu Do and
• Hai Bang Truong

Beilstein J. Nanotechnol. 2023, 14, 904–911, doi:10.3762/bjnano.14.74

• presented. Finally, we present the potential pathways and current problems in progressing MOF-based nanomaterials for CO2 conversion. Review Mechanism of CO2RR The process of CO2 reduction consists of three steps. First, the CO2 molecules are adsorbed on the active sites of catalysts. Second, charge

• transfer processes take place to create intermediates such as *CHO, *CO, and *COO. The process could include many electrons attending in the electrochemical reaction, and orientate the formed products. Finally, these species are desorbed from the active sites of electrocatalysts to generate various

Silver-based SERS substrates fabricated using a 3D printed microfluidic device

• Phommachith Sonexai,
• Minh Van Nguyen,
• Bui The Huy and
• Yong-Ill Lee

Beilstein J. Nanotechnol. 2023, 14, 793–803, doi:10.3762/bjnano.14.65

• formation of a charge-transfer complex between chemisorbed species and matrix material, which yields enhancement when the excitation frequency resonates with a charge-transfer transition [7]. Noble metal nanoparticles (NPs) have gained much popularity in various fields, such as analytical chemistry and

In situ magnesiothermic reduction synthesis of a Ge@C composite for high-performance lithium-ion batterie anodes

• Ha Tran Huu,
• Ngoc Phi Nguyen,
• Vuong Hoang Ngo,
• Huy Hoang Luc,
• Minh Kha Le,
• Minh Thu Nguyen,
• My Loan Phung Le,
• Hye Rim Kim,
• In Young Kim,
• Sung Jin Kim,
• Van Man Tran and
• Vien Vo

Beilstein J. Nanotechnol. 2023, 14, 751–761, doi:10.3762/bjnano.14.62

• the low-frequency region. The former component is characteristic of charge transfer resistance, while the latter presents the diffusion of ions in the solid phase. Compared to the pure Ge electrode, the diameters of the semicircle are smaller in the Ge@C electrodes because of the higher electrical

• conductivity of the additional carbon matrix, indicating the decrease in charge transfer resistance of the composite electrodes. The EIS results were fitted using an equivalent circuit model, including an internal or electrolyte resistance (Re), a charge transfer resistance (Rct), and two constant phase

• elements (CPE) [65]. According to Table 2, the charge transfer resistances of all Ge@C electrodes are much lower than the values of the pure Ge electrode, and Ge/C-iM750 exhibits the lowest value. The ionic conductivity was evaluated using the lithium-ion diffusion coefficient () using the following

A graphene quantum dots–glassy carbon electrode-based electrochemical sensor for monitoring malathion

• Sanju Tanwar,
• Aditi Sharma and
• Dhirendra Mathur

Beilstein J. Nanotechnol. 2023, 14, 701–710, doi:10.3762/bjnano.14.56

• , the sensor’s oxidation–reduction behavior was investigated. Electrochemical impedance spectroscopy was conducted to study the electrochemical properties of the modified the GQDs/GCE working electrode, which showed excellent charge transfer properties. We measured malathion in varying concentrations

• /reduction behavior and charge transfer resistance, cyclic voltammetry and electrochemical impedance spectroscopy were performed. An investigation of the relationship between concentrations and peak currents was conducted using differential pulse voltammetry (DPV). In this study, the modified GQD electrodes

• Brillouin zone, while the G band arises from vibrations in rings of sp2-hybridized atoms inside the GQDs. Electrochemical studies Electrochemical impedance spectroscopy In order to investigate the charge transfer on the electrode surfaces, electrochemical impedance spectroscopy (EIS) was used with the redox

Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review

• Akeem Adeyemi Oladipo,
• Saba Derakhshan Oskouei and
• Mustafa Gazi

Beilstein J. Nanotechnol. 2023, 14, 631–673, doi:10.3762/bjnano.14.52

• fluorophore ligands, which accounts for the excellent quenching effects of PET on the luminescence of the MOF sensor [54]. Photoinduced charge transfer (PCT): The PCT mechanism relies on the exchange of electrons between acceptor (analyte) and the donor (fluorophore), which results in the alteration of the

• fluorescence signals. A partial charge transfer of a fully conjugated system occurs in optical PCT sensors. This mechanism involves the complexation of donor and acceptor, which changes the electron energy levels and the fluorescence signals. While PET sensors have the electron donor moiety separated from the

• fluorophore by a spacer, PCT sensors typically feature an integrated receptor and fluorophore [46]. Intramolecular charge transfer (ICT): When the fluorophore contains both electron-withdrawing and electron-donating groups, ICT, an electron transfer process, takes place. In contrast to PET, the electronic

Conjugated photothermal materials and structure design for solar steam generation

• Chia-Yang Lin and
• Tsuyoshi Michinobu

Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36

• -withdrawing (EW) groups, such as malononitrile (DCV) and 2-(3-oxo-indan-1-ylidene)malononitrile (INCN) to the DPP core enhances the stability of DPP dyes [27]. In addition, when a thienyl spacer was introduced between the DPP and EW groups, efficient intramolecular charge transfer (ICT) interactions were

Evaluation of electrosynthesized reduced graphene oxide–Ni/Fe/Co-based (oxy)hydroxide catalysts towards the oxygen evolution reaction

• Karolina Cysewska,
• Marcin Łapiński,
• Marcin Zając,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2023, 14, 420–433, doi:10.3762/bjnano.14.34

• indicate charge transfer from cobalt to carbon and the formation of Co–O–C bonds in the catalyst [31]. Moreover, the spectra show that the dominant cobalt species in the studied catalysts were Co3+ and Co2+ [25]. The L3 edge of carbon in NiFe-GO and CoNiFe-GO is presented in Figure 3d. In general, the

• the improvement in the OER of NiFe-GO with the higher Qdep of NiFe and GO resulted mainly from the NiFe structure and the electroactive surface area and the porosity of GO. Electrochemical impedance spectroscopy (EIS) was performed in order to determine the charge transfer resistance (Rct) of the

• RHE with a scan rate of 5 mV·s−1. The EIS spectra were recorded in the frequency range from 10 kHz to 1 Hz at 1.6 V vs RHE and amplitude of 10 mV. In order to determine Rct, EIS spectra were fitted with a simple Randles model with the solution resistance, charge transfer resistance, and the constant

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

Bismuth-based nanostructured photocatalysts for the remediation of antibiotics and organic dyes

• Akeem Adeyemi Oladipo and
• Faisal Suleiman Mustafa

Beilstein J. Nanotechnol. 2023, 14, 291–321, doi:10.3762/bjnano.14.26

• semiconductor and a noble metal with an appropriate work function. A unidirectional charge transfer is enabled by the Schottky potential barrier, increasing charge density and separation [72]. Shen et al. [166] created a Schottky junction by synthesising NiSe2 nanosheets on top of BiVO4 nanosheets using a

High–low Kelvin probe force spectroscopy for measuring the interface state density

• Ryo Izumi,
• Masato Miyazaki,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• interface state density inside semiconductors. We derive an analytical expression for the electrostatic forces between a tip and a semiconductor sample in the accumulation, depletion, and inversion regions, taking into account the charge transfer between the bulk and interface states in semiconductors. We

• -low KPFS using high- and low-frequency AC bias voltages to measure the interface state density inside semiconductors. We derive an analytical expression for the electrostatic force between the tip and the sample that takes into account the charge transfer between the bulk and interface states in the

• -low KPFS using high-frequency and low-frequency AC bias voltages to measure the interface state density in semiconductors. We derived an analytical expression for the electrostatic force between the tip and the sample that takes into account the charge transfer between the bulk and interface states in

Structural, optical, and bioimaging characterization of carbon quantum dots solvothermally synthesized from o-phenylenediamine

• Zoran M. Marković,
• Milica D. Budimir,
• Martin Danko,
• Dušan D. Milivojević,
• Pavel Kubat,
• Danica Z. Zmejkoski,
• Vladimir B. Pavlović,
• Marija M. Mojsin,
• Milena J. Stevanović and
• Biljana M. Todorović Marković

Beilstein J. Nanotechnol. 2023, 14, 165–174, doi:10.3762/bjnano.14.17

• significantly, especially, by the presence and distribution of various functional groups on the basal plane and edges of carbon network, affecting, in turn, the CQD properties. Doping of CQDs with nitrogen, chlorine, or fluorine heteroatoms induces larger a transport bandgap, increased charge transfer

• resistance, and better antioxidant properties compared to pristine CQDs [5]. Functionalization of CQDs with amino groups (NH2 groups) induces a redshift of the photoluminescence because of the charge transfer from the amino groups to the carbon honeycomb core [6]. Also, grafting with NH2 groups, by means of

Induced electric conductivity in organic polymers

• Konstantin Y. Arutyunov,
• Anatoli S. Gurski,
• Vladimir V. Artemov,
• Alexander L. Vasiliev,
• Azat R. Yusupov,
• Danfis D. Karamov and
• Alexei N. Lachinov

Beilstein J. Nanotechnol. 2022, 13, 1551–1557, doi:10.3762/bjnano.13.128

• − ionization of the corresponding atoms, which enables effective charge transfer along the polymer chain [2]. (a) Schematics of a Pb (grey)–PDP (blue)–Pb (grey) three layer heterostructure on insulating substrate (not indicated for simplicity). The layout enables electron transport measurements of each lead

Photoelectrochemical water oxidation over TiO₂ nanotubes modified with MoS₂ and g-C₃N₄

• Phuong Hoang Nguyen,
• Thi Minh Cao,
• Tho Truong Nguyen,
• Hien Duy Tong and
• Viet Van Pham

Beilstein J. Nanotechnol. 2022, 13, 1541–1550, doi:10.3762/bjnano.13.127

• , which can improve the charge transfer states [33][34]. These two low-bandgap semiconductors improved considerably the PEC water splitting efficiency [35][36]. However, the fabrication of MoS2/TNAs and g-C3N4/TNAs has many disadvantages such as high synthesis temperatures, the requirement of a binder, or

• with previous publications [50][51][52]. Figure 5 shows the results of electrochemical impedance spectroscopy (EIS), that is, Nyquist and Mott–Schottky plots of the materials, which give information about the charge transfer mechanism at the interface. In Figure 5a, the Nyquist plots of the samples all

• exhibit only single semicircular shape, which shows the charge transfer resistance equivalent to the polarization resistance. This result also demonstrates a unique interaction of the electrode surface and the electrolyte solution. Furthermore, the g-C3N4 sample shows the semicircle with the largest

A TiO₂@MWCNTs nanocomposite photoanode for solar-driven water splitting

• Anh Quynh Huu Le,
• Ngoc Nhu Thi Nguyen,
• Hai Duy Tran,
• Van-Huy Nguyen and
• Le-Hai Tran

Beilstein J. Nanotechnol. 2022, 13, 1520–1530, doi:10.3762/bjnano.13.125

• performance because free electrons can shift to the trap state, resulting in a potential difference in the interface between the electrolyte and the electrode [40]. The Warburg element (W3) in the equilibrium circuit, indicating the contribution of diffusion to the overall charge transfer on the electrode, is

• frequencies [42][43]. Additionally, the equivalent circuit fitted to the TiO2@MWCNTs electrode indicates that electron and ion transfers and the electrode material contribute to the overall charge transfer [43]. The results suggest synergies of TiO2 nanoparticles and MWCNTs in the TiO2@MWCNTs electrode

Rapid and sensitive detection of box turtles using an electrochemical DNA biosensor based on a gold/graphene nanocomposite

• Abu Hashem,
• M. A. Motalib Hossain,
• Ab Rahman Marlinda,
• Mohammad Al Mamun,
• Khanom Simarani and
• Mohd Rafie Johan

Beilstein J. Nanotechnol. 2022, 13, 1458–1472, doi:10.3762/bjnano.13.120

• using electrochemical impedance spectroscopy (EIS) measurements. In 2.0 mM [Fe(CN)6]3−/4− containing 0.2 M KCl as the supporting electrolyte, the Nyquist plots of the SPCE, Gr/SPCE, AuNPs/SPCE, and AuNPs/Gr/SPCE are shown in Figure 3d. The inset is the equivalent circuit indicating the charge transfer

• -controlled charge-transfer process through the electrode–solution interface. Regarding the qualitative aspect, it was found that the nanocomposite-modified electrode shows a diffusion-limited charge transfer process. The bare SPCE comparatively showed lower charge transfer resistance at higher frequencies

• than that of individual nanomaterial-modified SPCEs, representing a limitation of electron transfer through the electrode–solution interface [56] for different electrode surfaces. The EIS plots for the modified SPCEs surfaces also reveal that the electrode–solution interfacial charge transfer process

LED-light-activated photocatalytic performance of metal-free carbon-modified hexagonal boron nitride towards degradation of methylene blue and phenol

• Nirmalendu S. Mishra and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2022, 13, 1380–1392, doi:10.3762/bjnano.13.114

• , lower charge transfer resistance, and improved charge carrier density (2.97 × 1019 cm−3). This subsequently enhanced the photocurrent density (three times) and decreased the photovoltage decay time (two times) in comparison to those of HBN. The electronic band structure (obtained through Mott–Schottky

• variation in the structural morphology results in development of multiple active sites that ensure adsorption and effective charge transfer [10]. On the other hand, HBN has been utilised as a support material in the formation of heterojunctions owing to its large surface area and separation of charge

• function by utilizing the Tauc plot mentioned in Equation 3. The obtained values were depicted in Figure 5a–e. The enhanced light absorption properties could be attributed to the grey/black colour of MBN and enhanced charge transfer attained due to the change in the electronic structure through the

Near-infrared photoactive Ag-Zn-Ga-S-Se quantum dots for high-performance quantum dot-sensitized solar cells

• Roopakala Kottayi,
• Ilangovan Veerappan and
• Ramadasse Sittaramane

Beilstein J. Nanotechnol. 2022, 13, 1337–1344, doi:10.3762/bjnano.13.110

• shown in the inset of Figure 7. The corresponding parameters are shown in Table 1. The Nyquist plot consists of two hemispheres, namely the high-frequency region hemisphere and the low-frequency region hemisphere. The high-frequency region hemisphere is associated with the charge transfer resistance (R1

• ) that appears at the interface of electrolyte and counter electrode. The low-frequency region hemisphere is attributed to the charge transfer resistance (R2) appearing at the interface of electrolyte and photoanode. The sheet resistance (Rs) is the resistance of the intercept of the real axis. Similarly

Recent trends in Bi-based nanomaterials: challenges, fabrication, enhancement techniques, and environmental applications

• Vishal Dutta,
• Ankush Chauhan,
• Ritesh Verma,
• C. Gopalkrishnan and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 1316–1336, doi:10.3762/bjnano.13.109

• increase in the overlap between Bi 6s and O 2p orbitals, a reduced charge transfer route, and strange floating features. In another approach, Huang et al. reported a one-step hydrothermal synthesis of a BiIO4/Bi2MoO6 hybrid photocatalyst for photodegradation of RhB dye [56]. Under visible-light irradiation

• activity was found to be significantly increased. This improvement was ascribed to the efficient interfacial charge transfer obtained as a consequence of the process. According to the active species trapping study, the photocatalysis process is significantly aided by the presence of photogenerated holes

• generation of Bi2WO6. It has been observed that the newly generated Bi2WO6 has a greater BET surface area and superior charge transfer kinetics. These properties point to an increase in photocatalytic activity. Other Bi-based hollow hierarchical structures, such as BiVO4, have the potential to be synthesized

Application of nanoarchitectonics in moist-electric generation

• Jia-Cheng Feng and
• Hong Xia

Beilstein J. Nanotechnol. 2022, 13, 1185–1200, doi:10.3762/bjnano.13.99

• ]. This viewpoint was confirmed by many experiments later, such as the electrical signal generated by the flow of water through single-walled carbon nanotubes [7], carbon nanosheets [8], and nanoparticles [9]. Regarding the principle of this phenomenon, the common explanation is that charge transfer

• interaction. The actual charge transfer is much more complicated, involving the contact angle, dielectric function, temperature, and ion concentration [15][16][17]. In MEGs, compared to bulk materials, nanoarchitectonics yields a higher specific surface area to the active material, which makes the contact

• area between the nanomaterial and the moisture larger and greatly improves the carrier yield. Therefore, in the abovementioned charge transfer mechanism, nanostructures theoretically yield better performance [18][19][20]. More researchers have also noticed that nanoarchitectonics can significantly

Rapid fabrication of MgO@g-C₃N₄ heterojunctions for photocatalytic nitric oxide removal

• Minh-Thuan Pham,
• Duyen P. H. Tran,
• Xuan-Thanh Bui and
• Sheng-Jie You

Beilstein J. Nanotechnol. 2022, 13, 1141–1154, doi:10.3762/bjnano.13.96

• and urea and, subsequently, characterized. Charge transfer dynamics in the heterojunction and band structure were investigated to understand the effect of the heterojunction on the photocatalytic activity. Finally, the photocatalytic pathway of the MgO@g-C3N4 heterojunction was studied via trapping

Recent advances in green carbon dots (2015–2022): synthesis, metal ion sensing, and biological applications

• Aisha Kanwal,
• Naheed Bibi,
• Sajjad Hyder,
• Arif Muhammad,
• Hao Ren,
• Jiangtao Liu and
• Zhongli Lei

Beilstein J. Nanotechnol. 2022, 13, 1068–1107, doi:10.3762/bjnano.13.93

Spindle-like MIL101(Fe) decorated with Bi₂O₃ nanoparticles for enhanced degradation of chlortetracycline under visible-light irradiation

• Chen-chen Hao,
• Fang-yan Chen,
• Kun Bian,
• Yu-bin Tang and
• Wei-long Shi

Beilstein J. Nanotechnol. 2022, 13, 1038–1050, doi:10.3762/bjnano.13.91

• –metal charge transfer (LMCT). For this reason, these MOFs are considered as emerging semiconductor-like photocatalysts and attention is growing toward these materials [26][27][28][29]. In 2007, Garcia and coworkers have first reported photocatalytic degradation of phenol by using MOF-5 as a

• suggests that the formation of the heterojunction can promote charge transfer on the interface between MIL101(Fe) and Bi2O3. Furthermore, the interfacial charge transfer behavior of the BOM-20 composite is also confirmed by EIS. In Figure 5d, BOM-20 exhibits the smallest arc radius, meaning that BOM-20

• /MIL101(Fe) heterojunctions can result in more effective electron–hole pair separation, higher interfacial electron transfer rate, and thus weakened charge transfer resistance, which may facilitate the improvement of Bi2O3/MIL101(Fe) photocatalytic activity. Photocatalytic degradation of chlortetracycline

Electrocatalytic oxygen reduction activity of AgCoCu oxides on reduced graphene oxide in alkaline media

• Iyyappan Madakannu,
• Indrajit Patil,
• Bhalchandra Kakade and
• Kasibhatta Kumara Ramanatha Datta

Beilstein J. Nanotechnol. 2022, 13, 1020–1029, doi:10.3762/bjnano.13.89

• °) than the supportless ACC-2* (40 ± 5°). The improved wettability can enhance the charge transfer rate between the electrolyte and the electrode, along with enabling effective electrical integration to reduce ohmic losses, boosting the ORR activity of ACC-2. We observed that ACC-2 displayed superior ORR

DNA aptamer selection and construction of an aptasensor based on graphene FETs for Zika virus NS1 protein detection

• Nathalie B. F. Almeida,
• Thiago A. S. L. Sousa,
• Viviane C. F. Santos,
• Camila M. S. Lacerda,
• Thais G. Silva,
• Rafaella F. Q. Grenfell,
• Flavio Plentz and
• Antero S. R. Andrade

Beilstein J. Nanotechnol. 2022, 13, 873–881, doi:10.3762/bjnano.13.78

• support this electron transfer from pyrene-modified molecules to graphene as the binding mechanism in π–π interactions between such compounds [35][36][37]. The association of pyrene-modified ZIKV60 aptamers with graphene may also be mediated by charge transfer that assists the interaction between the

• with NS1 due to exposure to protein dilutions of higher concentrations, such as 100 pg/mL. Consequently, further protein incorporation results in inappreciable specific recognition as well as negligible charge transfer to graphene. This observation has been made consistently with six additional

Self-assembly of C₆₀ on a ZnTPP/Fe(001)–p(1 × 1)O substrate: observation of a quasi-freestanding C₆₀ monolayer

• Guglielmo Albani,
• Michele Capra,
• Alessandro Lodesani,
• Alberto Calloni,
• Gianlorenzo Bussetti,
• Marco Finazzi,
• Franco Ciccacci,
• Alberto Brambilla,
• Lamberto Duò and
• Andrea Picone

Beilstein J. Nanotechnol. 2022, 13, 857–864, doi:10.3762/bjnano.13.76

• measurements reveal a negligible charge transfer at the C60/ZnTPP interface. Finally, the difference between the energy of the lowest unoccupied molecular orbital (LUMO) and that of the highest occupied molecular orbital (HOMO) measured on C60 is about 3.75 eV, a value remarkably higher than those found in

• relevant charge transfer between the overlayer and the substrate occurs. In contrast, a low Ea is characteristic of physisorbed molecules, for which the adsorption is mediated by the weak van der Waals interaction with the substrate. Chemisorption is the typical scenario for molecules stabilized on

• electronic gap equal to 3.75 eV. Finally, work function measurements have been performed to evaluate the charge transfer between the different layers constituting the heterostructure. Generally, electron transfer from the substrate (overlayer) to the overlayer (substrate) induces an increase (decrease) of