Simultaneous electrochemical determination of uric acid and hypoxanthine at a TiO₂/graphene quantum dot-modified electrode

• Vu Ngoc Hoang,
• Dang Thi Ngoc Hoa,
• Nguyen Quang Man,
• Le Vu Truong Son,
• Le Van Thanh Son,
• Vo Thang Nguyen,
• Le Thi Hong Phong,
• Ly Hoang Diem,
• Kieu Chan Ly,
• Ho Sy Thang and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 719–732, doi:10.3762/bjnano.15.60

• composite (TiO2/GQDs) obtained by in situ synthesis of GQDs, derived from coffee grounds, and peroxo titanium complexes was used as electrode modifier in the simultaneous electrochemical determination of uric acid and hypoxanthine. The TiO2/GQDs material was characterized by photoluminescence, X-ray

• diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, and energy-dispersive X-ray mapping. The TiO2/GQDs-GCE exhibits better electrochemical activity for uric acid and hypoxanthine than GQDs/GCE or TiO2/GCE in differential pulse voltammetry (DPV) measurements. Under optimized

• liquid chromatography [8], liquid chromatography–tandem mass spectrometry [9], and gas chromatography/mass spectrometry [10]. These approaches require complex handling procedures. Electrochemical techniques have been considered as a robust alternative for URI and HYP sensing because of their simplicity

Gold nanomakura: nanoarchitectonics and their photothermal response in association with carrageenan hydrogels

• Nabojit Das,
• Vikas,
• Akash Kumar,
• Sanjeev Soni and
• Raja Gopal Rayavarapu

Beilstein J. Nanotechnol. 2024, 15, 678–693, doi:10.3762/bjnano.15.56

• , electrochemical sensors, and photothermal therapy (PTT) [5]. These technologies are based on the principle of elastic scattering properties of metal nanoparticles and on the shift in the plasmon band, which is more prominent in the case of anisotropic nanoparticles in comparison to isotropic ones [6]. Several

Laser synthesis of nanoparticles in organic solvents – products, reactions, and perspectives

• Theo Fromme,
• Sven Reichenberger,
• Katharine M. Tibbetts and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2024, 15, 638–663, doi:10.3762/bjnano.15.54

• aqueous solutions produces free electrons and ROS. The ROS lead to a certain degree of nanoparticle (surface) oxidation depending on the material’s standard electrochemical reduction potential for LAL and LFL. For LRL, both electrons and ROS contribute to the reduction reactions of the metal salts

• via the liquid displacement method and gas chromatography (Figure 3) [51]. The amount of formed hydrogen was found to be inversely correlated with the metal’s standard electrochemical reduction potential, resulting in higher hydrogen formation rates during the ablation of less noble metals such as Ti

• , Fe, and Al. As the H2/O2 ratio follows the same trend, redox reactions occurring between the formed nanoparticles and the formed oxygen species lead to the particles’ surface oxidation. This correlation shows that metals with a lower standard electrochemical reduction potential than hydrogen (E0 < 0

Photocatalytic degradation of methylene blue under visible light by cobalt ferrite nanoparticles/graphene quantum dots

• Vo Chau Ngoc Anh,
• Le Thi Thanh Nhi,
• Le Thi Kim Dung,
• Dang Thi Ngoc Hoa,
• Nguyen Truong Son,
• Nguyen Thi Thao Uyen,
• Nguyen Ngoc Uyen Thu,
• Le Van Thanh Son,
• Le Trung Hieu,
• Tran Ngoc Tuyen and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2024, 15, 475–489, doi:10.3762/bjnano.15.43

• breaking graphene sheets or from molecules with aromatic structure (fullerenes, starch, and carbohydrates) [3]. However, often GQDs are only stable in solvents, which limits their application in fields that require their solid form, such as in adsorption and photocatalytic, or electrochemical applications

Controllable physicochemical properties of WO_x thin films grown under glancing angle

• Rupam Mandal,
• Aparajita Mandal,
• Alapan Dutta,
• Rengasamy Sivakumar,
• Sanjeev Kumar Srivastava and
• Tapobrata Som

Beilstein J. Nanotechnol. 2024, 15, 350–359, doi:10.3762/bjnano.15.31

• . In this regard, radio frequency (rf) sputter deposition is one of the preferred choices as an industry-compatible method to grow WOx thin films [2][19][20][21]. Apart from thin films, nanostructured metal oxides generally possess superior electrochemical properties compared to their bulk counterparts

• electrochemical property variation of the underlying films induced by structural changes. Therefore, a systematic investigation on the surface work function of the NS-WOx films as a function of thickness holds the potential for accessing its practical device application. In this article, we report on tunable

In situ optical sub-wavelength thickness control of porous anodic aluminum oxide

• Aleksandrs Dutovs,
• Raimonds Popļausks,
• Oskars Putāns,
• Vladislavs Perkanuks,
• Aušrinė Jurkevičiūtė,
• Tomas Tamulevičius,
• Uldis Malinovskis,
• Iryna Olyshevets,
• Donats Erts and
• Juris Prikulis

Beilstein J. Nanotechnol. 2024, 15, 126–133, doi:10.3762/bjnano.15.12

• consistently manufacturing PAAO with the targeted thickness. An electrochemical cell with an optical window was designed for reflectance spectroscopy of PAAO during anodization. Real-time fitting of spectra to a transfer-matrix model enabled continuous monitoring of the thickness growth of the PAAO layer

• of templates, including evaporation masks [8][9][10], molds for nanowire array production using the supercritical fluid method [11], electrochemical deposition [12], atomic layer deposition [13], or traps for colloidal nanoparticle assembly [14]. Several applications, for example, color filtering [15

Influence of conductive carbon and MnCo₂O₄ on morphological and electrical properties of hydrogels for electrochemical energy conversion

• Sylwia Pawłowska,
• Karolina Cysewska,
• Yasamin Ziai,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2024, 15, 57–70, doi:10.3762/bjnano.15.6

• electrochemically active surfaces. The great advantage of the 3D hydrogel structure is the increase of the catalytic surface area thanks to the possibility of conducting the electrochemical reaction deeper into the structure of the hydrogel. Generation of free space in the form of pores and network structure within

• porous structure is capable of swelling and thus accommodating large amounts of ionic liquids. Moreover, the swollen hydrogel structure provides constant access of electrolyte molecules/ions to the catalyst particles, increasing the speed and efficiency of the electrochemical reaction [20]. The swelling

• conductive component at the stage of hydrogel synthesis. Hydrogel matrices are an excellent medium for depositing metallic nanocatalysts, especially in reactions requiring aqueous media such as electrochemical processes. The dispersion of the catalyst particles in the hydrogel helps to avoid or significantly

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

• of converting CO2 into valuable chemicals through electrochemical techniques has garnered significant attention. Metal-organic frameworks (MOFs) have occured as highly prospective materials for the reduction of CO2, owing to their exceptional attributes including extensive surface area, customizable

• CO2 conversion. Finally, a meticulous discourse encompasses the challenges encountered and the prospects envisioned for the advancement of MOF-based nanomaterials in the realm of electrochemical reduction of CO2. Keywords: carbon capture; CO2 reduction; electrocatalysis; metal-organic frameworks

• valuable compounds through electrochemical reduction. The electrocatalytic process for CO2 reduction reactions (CO2RR) encounters a persistent obstacle in the activation of CO2 [4]. The formation of CO2•− necessitates a high thermodynamic potential of −1.90 V vs the standard hydrogen electrode

N-Heterocyclic carbene-based gold etchants

• Robert B. Chevalier,
• Justin Pantano,
• Matthew K. Kiesewetter and
• Jason R. Dwyer

Beilstein J. Nanotechnol. 2023, 14, 865–871, doi:10.3762/bjnano.14.71

• without the need for Au/Ag alloys. Porous gold, itself, provides a gold film with high surface area that can be advantageous for energy conversion, catalysis, and electrochemical sensing [9][31]. Experimental Compounds 1 and 3 were prepared based on previously reported work [15][19], with 3 prepared by

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

• report an in situ magnesiothermic reduction to synthesize a composite of Ge@C as an anode material for lithium-ion batteries. The obtained electrode delivered a specific capacity of 454.2 mAh·g−1 after 200 cycles at a specific current of 1000 mA·g−1. The stable electrochemical performance and good rate

• nanoparticles and a carbon matrix using a hydrothermal route has been reported, and the enhancement in the electrochemical performance of Ge@C electrodes was demonstrated [33]. In this work, a one-pot synthesis route has been followed to prepare a Ge@C composite using an in situ magnesiothermic reduction of

• GeO2 and biomass-derived carbon as precursor. A series of experiments using other methods to combine Ge and biomass carbon was also conducted for comparison. The in situ synthesized electrode exhibits superior electrochemical performance in lithium storage. This is attributed to a better contact

Cross-sectional Kelvin probe force microscopy on III–V epitaxial multilayer stacks: challenges and perspectives

• Mattia da Lisca,
• José Alvarez,
• James P. Connolly,
• Nicolas Vaissiere,
• Karim Mekhazni,
• Jean Decobert and
• Jean-Paul Kleider

Beilstein J. Nanotechnol. 2023, 14, 725–737, doi:10.3762/bjnano.14.59

• 1 × 1018 cm−3. The three Zn doping levels of InP layers were purposely inverted along the growth direction to facilitate electrochemical capacitance–voltage (ECV) characterization due to the strong Zn diffusion. The InP:Zn and the GaInAsP:Zn layers were epitaxially grown at a surface temperature of

Nanomaterials for photocatalysis and applications in environmental remediation and renewable energy

• Viet Van Pham and
• Wee-Jun Ong

Beilstein J. Nanotechnol. 2023, 14, 722–724, doi:10.3762/bjnano.14.58

• with various morphologies demonstrated many preeminent features in the above applications. In detail, the MoS2 with a honeycomb-like structure was first synthesized by an electrochemical route and applied in dye-sensitized solar cells [19], which expressed a higher applicability than that of other

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

• diffraction were used to characterize the morphological and structural properties of GQDs. An electrochemical sensor was developed by drop casting GQDs on a glassy carbon electrode (GCE). The sensor detects the organophosphate pesticide malathion in a selective and sensitive manner. Using cyclic voltammetry

• , 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

• between 1 to 30 µM using differential pulse voltammetry, which resulted in a limit of detection of 0.62 nM. GQDs can thus be used to develop electrochemical sensors for the detection of pesticides in water. Keywords: cyclic voltammetry; differential pulse voltammetry; electrochemical impedance

Humidity-dependent electrical performance of CuO nanowire networks studied by electrochemical impedance spectroscopy

• Jelena Kosmaca,
• Juris Katkevics,
• Jana Andzane,
• Raitis Sondors,
• Liga Jasulaneca,
• Raimonds Meija,
• Kiryl Niherysh,
• Yelyzaveta Rublova and
• Donats Erts

Beilstein J. Nanotechnol. 2023, 14, 683–691, doi:10.3762/bjnano.14.54

• , Riga, Latvia 10.3762/bjnano.14.54 Abstract Electrochemical impedance spectroscopy was applied for studying copper oxide (CuO) nanowire networks assembled between metallic microelectrodes by dielectrophoresis. The influence of relative humidity (RH) on electrical characteristics of the CuO nanowire

• ; electrochemical impedance spectroscopy; humidity; nanowire; sensor; Introduction Semiconductor metal oxide nanomaterials have demonstrated a great potential for integration in a variety of devices, such as gas and humidity sensors, nanoelectronics, and low-power thermoelectrical generators [1][2][3][4][5][6

• compositions aligned by DEP [25]. In some of these works, electrochemical impedance spectroscopy (EIS) was used as an effective tool to study the effects of chemical and physical absorption of water on the nanostructured surfaces of active CuO elements of the systems [23][24]. To the best of our knowledge, the

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

• antibiotics and hormones in the environment and food samples are concerning and pose a threat. Opto-electrochemical sensors have received attention due to their low cost, portability, sensitivity, analytical performance, and ease of deployment in the field as compared to conventional expensive technologies

• that are time-consuming and require experienced professionals. Metal-organic frameworks (MOFs) with variable porosity, active functional sites, and fluorescence capacity are attractive materials for developing opto-electrochemical sensors. Herein, the insights into the capabilities of electrochemical

• , high-performance MOFs as commercially viable next-generation opto-electrochemical sensor materials for the detection and monitoring of diverse analytes are discussed. Keywords: antibiotics sensing; endocrinal disorders; fluorescent sensor; hormones sensors; luminescent sensor; MOF nanohybrids

Titania nanoparticles for photocatalytic degradation of ethanol under simulated solar light

• Evghenii Goncearenco,
• Iuliana P. Morjan,
• Claudiu Teodor Fleaca,
• Florian Dumitrache,
• Elena Dutu,
• Monica Scarisoreanu,
• Valentin Serban Teodorescu,
• Alexandra Sandulescu,
• Crina Anastasescu and
• Ioan Balint

Beilstein J. Nanotechnol. 2023, 14, 616–630, doi:10.3762/bjnano.14.51

• electrochemical, and photochemical methods [25]. Ethanol obtained from biomass is a renewable resource, and hydrogen has a high energy content and does not produce greenhouse gases by burning. Hence, it is an ideal combustible for the future [25]. TiO2 has some advantages over commonly used catalytic Pt- or Pt

SERS performance of GaN/Ag substrates fabricated by Ag coating of GaN platforms

• Magdalena A. Zając,
• Bogusław Budner,
• Malwina Liszewska,
• Bartosz Bartosewicz,
• Łukasz Gutowski,
• Jan L. Weyher and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2023, 14, 552–564, doi:10.3762/bjnano.14.46

• plasmonic metals or their alloys [23][24][25][26][27][28][29][30][31][32]. The chemical and electrochemical etching of GaN heteroepitaxial layers leads to various nanostructures formed on line defects (dislocations), such as straight nanopillars, bunches of nanopillars, and pits [31][32]. The nanostructured

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• multistep electrochemical epitaxial polymerization technique [113]. This technique consists of combining two electrochemical polymerization processes using different monomer solutions. First, a voltage pulse was applied to an iodine-covered Au(111) substrate in an electrolyte solution containing the first

• substrate. This process resulted in the formation of heterowires in which the polymer initially formed on the substrate was linked to another type of thiophene polymer that was growing. In this way, nanoarchitectonics of conjugated polymers can be obtained on metal surfaces by multistep electrochemical

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

• additives that could interfere with the structural and electrochemical measurements. The effects of the addition of GO to NiFe and CoNiFe on their morphological, structural, and OER electrocatalytic properties were studied. The role of GO and metallic species in the OER electrocatalytic process is discussed

• reduction of the GO. A reduced form of GO combined with NiFe was also obtained by others after one-step electrodeposition by cyclic voltammetry [12]. Electrochemical studies of the catalysts towards the OER The electrochemical performance of the catalysts towards the OER was studied in an aqueous solution

• NiFe-GO revealed a higher catalytic activity towards the OER than NiFe and GO alone and the other catalysts, further electrochemical studies focused on this material. Figure 6 and Figure 7 present the effect of the change in the electrodeposition charge Qdep of NiFe in NiFe-GO and GO in NiFe-GO

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

• -photochemical techniques, such as chemical, radiation-induced, cavitation, electrochemical techniques, and photochemical processes [11][15][16][17]. One of the AOPs, photocatalysis, uses natural light – a resource that is both clean and recyclable – to completely degrade a variety of organic pollutants and

• absorption range. In addition to improving the photocatalytic properties of the Bi-based host materials, doping them with rare earth elements may also give them special ferroelectric and ferromagnetic properties, as well as electrochemical and luminescent properties. To produce an Er-doped Bi2WO6

A novel approach to pulsed laser deposition of platinum catalyst on carbon particles for use in polymer electrolyte membrane fuel cells

• Bogusław Budner,
• Wojciech Tokarz,
• Sławomir Dyjak,
• Andrzej Czerwiński,
• Bartosz Bartosewicz and
• Bartłomiej Jankiewicz

Beilstein J. Nanotechnol. 2023, 14, 190–204, doi:10.3762/bjnano.14.19

• graphitization were used as carbon supports. The best electrochemical measurement results were obtained for Pt deposited on Vulcan XC-72R. The peak power density measured for this material in a membrane electrode assembly (MEA) of a PEMFC (fed with H2/Air) was 0.41 W/cm2, which is a good result compared to 0.57

• and an electrochemical catalyst for electrochemical reactions under low temperatures, are typically used in automobiles and portable electronics [4][5]. The primary application potential is related to their compact size, lightweight, high power density, and low operating temperature. However, they

• , morphology, and chemical composition of the fabricated catalysts were investigated using TEM, SEM, EDX, XPS, and Raman spectroscopy. Electrochemical measurements determined the performance of the fabricated catalysts. Results and Discussion Synthesis of a highly graphitized carbon material The synthesis of

Utilizing the surface potential of a solid electrolyte region as the potential reference in Kelvin probe force microscopy

• Nobuyuki Ishida

Beilstein J. Nanotechnol. 2022, 13, 1558–1563, doi:10.3762/bjnano.13.129

• Nobuyuki Ishida National Institute for Materials Science, Sengen 1-2-1, Tsukuba, Ibaraki 305-0047, Japan 10.3762/bjnano.13.129 Abstract In electrochemical measurements, monitoring the electrode potential using a stable reference is essential for controlling the redox reactions that occur at the

• electrodes. In Kelvin probe force microscopy (KPFM) measurements on electrochemical cells, the surface potential is generally measured relative to electrical ground instead of a stable reference. Here, we show that the changes in the surface potential, measured using KPFM relative to the surface potential in

• , in the case of electrochemical devices such as batteries, the redox reactions that occur at the electrode are determined by the potential difference across the electrode–electrolyte interface, not the electrode potential relative to ground. This prevents the accurate consideration of redox reactions

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

• . Hydrogen is often synthesized via hydrocarbon compounds or water electrolysis [1]. Methods to produce hydrogen via electrochemical or photo-electrochemical (PEC) water splitting are considered a future direction of renewable fuel development [2][3][4]. The use of solar energy to activate catalytic

• 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

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

• diffraction (XRD, D2 PHASER). The chemical structure of the samples is characterized using Fourier-transform infrared spectroscopy (FTIR, Brucker 27). The electrochemical measurements are carried out on a MPG2 Biologic system with a three-electrode cell controlled by ECLab® software. Diffuse reflectance

• spectra (DRS) are recorded with a spectrophotometer (FL-1039, HORIBA) using a 450 W xenon lamp. A portable Lux-meter (MW700, Milwaukee) and a pyranometer (SR30, Huseflux) are used for sunlight intensity and irradiance measurements. Photoelectrochemical measurements Electrochemical measurements are

• electrode [35]. Based on the cyclic voltammetry results, it could be suggested that the TiO2@MWCNTs electrode is superior regarding photoelectrochemical application compared to TiO2 and MWCNTs electrodes. Electrochemical impedance spectroscopy (EIS) is applied to characterize the electron-transfer property

Structural studies and selected physical investigations of LiCoO₂ obtained by combustion synthesis

• Monika Michalska,
• Paweł Ławniczak,
• Tomasz Strachowski,
• Adam Ostrowski and
• Waldemar Bednarski

Beilstein J. Nanotechnol. 2022, 13, 1473–1482, doi:10.3762/bjnano.13.121

• improve electrical conductivity and electrochemical performance [5][6][7][9][13][14][15][16][23][24][25][26][27][28][29][30][31][32]. Nanostructured materials can reduce the specific surface current rate as well as improve stability and specific capacity [23][24][25][26][27][28][29]. LiCoO2 has been