Nanotechnology-based approaches for the removal of microplastics from wastewater: a comprehensive review

• Nayanathara O Sanjeev,
• Manjunath Singanodi Vallabha and
• Rebekah Rubidha Lisha Rabi

Beilstein J. Nanotechnol. 2025, 16, 1607–1632, doi:10.3762/bjnano.16.114

• reactive radicals act as strong oxidizing agents, attacking pollutants by breaking their chemical bonds, ultimately leading to their degradation and mineralization [97]. For a compound to undergo oxidation using a photocatalyst, its redox potential should be higher than the valence band edge of the

• semiconductor catalyst. In contrast, for reduction to occur, the redox potential must be lower than the conduction band edge. This is because, upon excitation, holes generated in the valence band participate in oxidation reactions, whereas the electrons excited to the conduction band drive the reduction

Photocatalytic degradation of ofloxacin in water assisted by TiO₂ nanowires on carbon cloth: contributions of H₂O₂ addition and substrate absorbability

• Iram Hussain,
• Lisha Zhang,
• Zhizhen Ye and
• Jin-Ming Wu

Beilstein J. Nanotechnol. 2025, 16, 1567–1579, doi:10.3762/bjnano.16.111

• and CC/NW-450 °C. The black carbon cloth absorbs light in the wavelength range of 250–800 nm, and the UV adsorption edge can be seen clearly after TiO2 precipitations. According to the Kubelka–Munk formula, assuming an indirect transition between valence and conduction bands [24], the bandgap for the

Synthesis and antibacterial properties of nanosilver-modified cellulose triacetate membranes for seawater desalination

• Lei Wang,
• Shizhe Li,
• Kexin Xu,
• Wenjun Li,
• Ying Li and
• Gang Liu

Beilstein J. Nanotechnol. 2025, 16, 1380–1391, doi:10.3762/bjnano.16.100

• provide compelling evidence for the successful surface modification of CTA with PDA and the subsequent immobilization of Ag on the PCTA surface via coordination bonds. In order to clarify the valence state of Ag, XPS was employed to provide detailed information about the elemental composition and chemical

Electronic and optical properties of chloropicrin adsorbed ZnS nanotubes: first principle analysis

• Prakash Yadav,
• Boddepalli SanthiBhushan and
• Anurag Srivastava

Beilstein J. Nanotechnol. 2025, 16, 1184–1196, doi:10.3762/bjnano.16.87

• the ZnS NT system upon CP adsorption. Notably, the interaction of CP introduces distinct states near both the conduction and valence bands. Unlike the pristine ZnS NT, the PDOS of CP-adsorbed ZnS NTs shows new peaks around 1 eV (relative to the Fermi level), primarily consisting of states from the d

• between the valence and conduction bands, reflecting the fundamental optical properties of the material. Furthermore, the absence of significant absorption in the visible region (>400 nm) underscores the lack of mid-gap states in pristine ZnS NTs. Such optical characteristics align with previous reports

Ar⁺ implantation-induced tailoring of RF-sputtered ZnO films: structural, morphological, and optical properties

• Manu Bura,
• Divya Gupta,
• Arun Kumar and
• Sanjeev Aggarwal

Beilstein J. Nanotechnol. 2025, 16, 872–886, doi:10.3762/bjnano.16.66

• represent sub-bandgap absorptions due to defects. The optical bandgap values decrease after implantation from 3.29 ± 0.05 eV to 2.89 ± 0.04 eV with the rise in ion fluence. This is assigned to the emergence of defect-trapping levels between valence band and conduction band [46]. These trapping levels can be

• acceptor level or donor levels present at the top of the valence band or at the bottom of the conduction band, respectively. This results in a decrease in the energy separation between the valence band and the conduction band. Also, the sub-bandgap values decrease with increase in ion fluence as shown in

Insights into the electronic and atomic structures of cerium oxide-based ultrathin films and nanostructures using high-brilliance light sources

• Paola Luches and
• Federico Boscherini

Beilstein J. Nanotechnol. 2025, 16, 860–871, doi:10.3762/bjnano.16.65

• sensitivity of the method and to selectively probe the surface and or deeper layers, like buried interfaces. Since the early studies of epitaxial cerium oxide films by Mullins and coworkers [22], it became clear that synchrotron radiation could provide high-resolution Ce 3d, Ce 4d, and valence band spectra

• understanding of cerium oxide-based systems was introduced by the application of resonant photoemission to selectively probe valence band features related to Ce4+ and Ce3+ ions. This can be done by tuning the photon energy at specific resonances related to Ce 4d→Ce 4f0 (Ce4+) and Ce 4d→Ce 4f1 (Ce3+) electronic

• configurations at 110 and 125 eV, respectively [23][25][26][27][28]. Figure 1 reports valence band spectra from an ultrathin cerium oxide film before and after ultrahigh vacuum (UHV) annealing at 600 °C, acquired at the two resonant energies. Using a photon energy at the Ce4+-related resonance (110 eV), the

Supramolecular hydration structure of graphene-based hydrogels: density functional theory, green chemistry and interface application

• Hon Nhien Le,
• Duy Khanh Nguyen,
• Minh Triet Dang,
• Huyen Trinh Nguyen,
• Thi Bang Tam Dao,
• Trung Do Nguyen,
• Chi Nhan Ha Thuc and
• Van Hieu Le

Beilstein J. Nanotechnol. 2025, 16, 806–822, doi:10.3762/bjnano.16.61

• graphene with the intersheet distance of 3.459 Å (a), and its valence–conduction band structure in hexagonal Brillouin zone (b). The AB bilayer graphene structure intercalated with a layer of water molecules and the intersheet distance of 6.626 Å (c), and its electronic band structure in hexagonal

Thickness dependent oxidation in CrCl₃: a scanning X-ray photoemission and Kelvin probe microscopies study

• Shafaq Kazim,
• Rahul Parmar,
• Maryam Azizinia,
• Matteo Amati,
• Muhammad Rauf,
• Andrea Di Cicco,
• Seyed Javid Rezvani,
• Dario Mastrippolito,
• Luca Ottaviano,
• Tomasz Klimczuk,
• Luca Gregoratti and
• Roberto Gunnella

Beilstein J. Nanotechnol. 2025, 16, 749–761, doi:10.3762/bjnano.16.58

• Cl and Cr core levels at room temperature (RT). By monitoring the core levels and valence band spectra at various spatial resolutions (≥0.13 μm), we obtained quantitative maps of the chemical composition to correlate these maps with the thicknesses measured by AFM. Additionally, we investigated the

• mapping of the work function and surface atomic states [29]. This technique establishes a correlation between the valence band photoemission data and the morphological information, offering insights into the position of the conduction band [30]. Results and Discussion Optical contrast and AFM It is well

• [35]. Valence band results The valence band spectra of CrCl3 flakes were recorded at the two different regions T and L. Figure 10 shows the valence band maxima (VBMs) for both regions. The VBM of point L is about 1.82 V, while for point T, it is about 1.74 V; the difference of 0.08 V is significantly

Nanostructured materials characterized by scanning photoelectron spectromicroscopy

• Matteo Amati,
• Alexey S. Shkvarin,
• Alexander I. Merentsov,
• Alexander N. Titov,
• María Taeño,
• David Maestre,
• Sarah R. McKibbin,
• Zygmunt Milosz,
• Ana Cremades,
• Rainer Timm and
• Luca Gregoratti

Beilstein J. Nanotechnol. 2025, 16, 700–710, doi:10.3762/bjnano.16.54

• of (Ni,Fe)4Se5 (Figure 1g,h). The identical orientation of the (Ni,Fe)4Se5 crystals indicates that they have undergone coherent coupling with the lattice of the main crystal. The SPEM technique enables the determination of both the composition of inclusions and the shape of the valence band (Figure

• the local binding energy position of the core level directly follows the energy of the valence and conduction band and thus the band-bending at the interface between the p- and n-doped segments, the observed shift in binding energy directly reflects the in-built potential of the p–n junction at the

• imaging modes. Figure 3 shows Ni 3p, O 1s, and valence band XPS spectra from samples annealed at diverse temperatures, which exhibit variable morphological, crystallographic, and optical properties. Regarding the Ni 3p signal, less-explored so far, four main bands were observed after signal deconvolution

Emerging strategies in the sustainable removal of antibiotics using semiconductor-based photocatalysts

• Yunus Ahmed,
• Keya Rani Dutta,
• Parul Akhtar,
• Md. Arif Hossen,
• Md. Jahangir Alam,
• Obaid A. Alharbi,
• Hamad AlMohamadi and
• Abdul Wahab Mohammad

Beilstein J. Nanotechnol. 2025, 16, 264–285, doi:10.3762/bjnano.16.21

• bandgap, electrons (e−) in the valence band (VB) transition to the conduction band (CB), resulting in the formation of holes (h+) in the VB (photocatalyst + hν → photocatalyst + h+ + e−) [54][55]. Afterwards, the electrons and holes are effectively separated and move toward the surface of the

• enable localized surface plasmonic resonance (LSPR). The second strategy focuses on the development of heterojunctions between two semiconductors that is activated by visible light [65][66]. These heterojunctions should have bandgaps and energy levels that match the valence and conduction bands

• potential difference is applied in heterojunction systems, electrons transfer from the conduction band (CB) of semiconductor 1 (SC1) to the CB of semiconductor 2 (SC2). At the same time, holes in the valence band (VB) of SC1 migrate to the VB of SC2. This charge transfer occurs in type-I heterojunctions, as

Recent advances in photothermal nanomaterials for ophthalmic applications

• Jiayuan Zhuang,
• Linhui Jia,
• Chenghao Li,
• Rui Yang,
• Jiapeng Wang,
• Wen-an Wang,
• Heng Zhou and
• Xiangxia Luo

Beilstein J. Nanotechnol. 2025, 16, 195–215, doi:10.3762/bjnano.16.16

• bandgap width of TiO2 (≈3.3 eV) is relatively large; thus, absorption of visible light is very weak. Through non-metallic doping, some localized states can be generated above the O 2p orbitals, and the valence band of TiO2 can be reconstructed, resulting in an upward shift of the valence band and a

Clays enhanced with niobium: potential in wastewater treatment and reuse as pigment with antibacterial activity

• Silvia Jaerger,
• Patricia Appelt,
• Mario Antônio Alves da Cunha,
• Fabián Ccahuana Ayma,
• Ricardo Schneider,
• Carla Bittencourt and
• Fauze Jacó Anaissi

Beilstein J. Nanotechnol. 2025, 16, 141–154, doi:10.3762/bjnano.16.13

• . The small decrease in values occurred due to the bentonite clay with high bandgap values, which generated impurity energy levels above the valence band edge. This results in lower energy values required to excite charge carriers, reducing the optical band [24]. Figure 8 shows the results of the

• comparison obtained regarding the percentage of removal from adsorption and heterogeneous photocatalysis tests. The photocatalysis mechanism can be explained as follows: a semiconductor such as the BEPh and BEOx samples absorbs a photon, promoting an electron from the valence band (VB) to the conduction band

• (CB), creating a hole in the valence band (hBV+) [8]. These holes induce the oxidative decomposition of organic molecules adsorbed on the catalytic surface. They also react with water molecules, producing the hydroxyl radical (OH•). This radical rapidly attacks the dye molecules in the solution

Theoretical study of the electronic and optical properties of a composite formed by the zeolite NaA and a magnetite cluster

• Joel Antúnez-García,
• Roberto Núñez-González,
• Vitalii Petranovskii,
• H’Linh Hmok,
• Armando Reyes-Serrato,
• Fabian N. Murrieta-Rico,
• Mufei Xiao and
• Jonathan Zamora

Beilstein J. Nanotechnol. 2025, 16, 44–53, doi:10.3762/bjnano.16.5

• magnitude of the largest vector in charge density Fourier expansion is Gmax = 12.0. The energy to separate the valence states of the core states was set at a value of −7.5 Ry; thus, the Al [1s2 2s2], O [1s2], Si [1s2 2s2], Na [1s2], and Fe [1s2 2s2 2p6] electronic states are considered as core states, and

• the rest of electronic states as valence states. For integration in the reciprocal space, a 3 × 3 × 3 mesh (14 k-points in the irreducible Brillouin Zone (IBZ)) is used during the self-consistent cycle, and a 6 × 6 × 6 mesh (112 k-points in IBZ) for the calculation of density of states and optical

• 0.01 e/Bohr3. This calculation considers only the valence states. The computed values of the difference fall within the range of −0.009 to 1.794 e/Bohr3, indicating that the effective component corresponds solely to spin up, consistent with observations in Figure 4b. Furthermore, the figure

The round-robin approach applied to nanoinformatics: consensus prediction of nanomaterials zeta potential

• Dimitra-Danai Varsou,
• Arkaprava Banerjee,
• Joyita Roy,
• Kunal Roy,
• Giannis Savvas,
• Haralambos Sarimveis,
• Ewelina Wyrzykowska,
• Mateusz Balicki,
• Tomasz Puzyn,
• Georgia Melagraki,
• Iseult Lynch and
• Antreas Afantitis

Beilstein J. Nanotechnol. 2024, 15, 1536–1553, doi:10.3762/bjnano.15.121

• descriptors) were obtained after Stepwise Selection, GA, and BSS. These are Hamaker (self/water), amount of Ce, amount of Zr, rod (shape), coating, the total number of atoms, tot_metal_alpha, Metals_SumIP, X_ActivM, and Valence electron potential. Additionally, we performed a correlation analysis of the

Strain-induced bandgap engineering in 2D ψ-graphene materials: a first-principles study

• Kamal Kumar,
• Nora H. de Leeuw,
• Jost Adam and
• Abhishek Kumar Mishra

Beilstein J. Nanotechnol. 2024, 15, 1440–1452, doi:10.3762/bjnano.15.116

• valence and conduction bands in the EBS. This material is a direct-bandgap material with the alignment of the conduction band’s minima and valence band’s maxima at the same k-points in the Brillouin zone (Figure 1c). We tabulate the structural parameters, bandgap, and buckling heights of these structures

• negative strain in the lattice plane, ψ-graphene maintains its conductive nature until −13%; at −14%, a bandgap of ≈0.2 eV emerges between the valence and conduction bands as shown in Figure 2. Beyond −14% negative strain, a proportional increment in the bandgap is observed, reaching its maximum value of

• -graphene nanosheet can tolerate before structural breakdown. The EBS of ψ-graphene, plotted in Figure 2b at −14%, reveals a direct transition of electrons from the valence band to the conduction band, but beyond −14% strain, no direct transition is possible, indicating the indirect nature of the bandgap of

Quantum-to-classical modeling of monolayer Ge₂Se₂ and its application in photovoltaic devices

• Anup Shrivastava,
• Shivani Saini,
• Dolly Kumari,
• Sanjai Singh and
• Jost Adam

Beilstein J. Nanotechnol. 2024, 15, 1153–1169, doi:10.3762/bjnano.15.94

• . Figure 3 depicts that the monolayer Ge2Se2 is a direct-bandgap semiconductor with a bandgap of the order of 1.12 eV. Valence band maximum (VBM) and conduction band minimum (CBM) are located along the Γ-X path. The computed bandgap value and its dispersion nature are consistent with earlier reported works

• ), conduction/valence band density of states, electron/hole mobility, electron affinity, and work function can be derived from the initial band energy calculation. We calculated the effective masses of electrons and holes as = 0.167me and = 0.1768me, respectively, which are very close to the values ( = 0.17me

• ). Interestingly, we can observe tracking bands (the region where the energy difference between the conduction and valence bands is approximately constant [49]) around the high-symmetry point S and between X and Y in the first Brillouin zone. Around these points, we notice a small gradient and, thus, large DOS

A review on the structural characterization of nanomaterials for nano-QSAR models

• Salvador Moncho,
• Eva Serrano-Candelas,
• Jesús Vicente de Julián-Ortiz and
• Rafael Gozalbes

Beilstein J. Nanotechnol. 2024, 15, 854–866, doi:10.3762/bjnano.15.71

• , area and volume of the cluster, energies of HOMO and LUMO orbitals and the gap between them, and lattice energies [22][26]. The energy levels of conduction and valence bands, which are found commonly among the most important parameters, can be calculated from QM models or derived from other simple

• reflectance UV–vis spectra). Alternative formulations for valence and conduction band energies, based only on pre-known physicochemical constants and values from reference handbooks, have been reported as well [79][80]. Furthermore, the electric characteristics of the nanoparticle surface can be reported by

Intermixing of MoS₂ and WS₂ photocatalysts toward methylene blue photodegradation

• Maryam Al Qaydi,
• Nitul S. Rajput,
• Michael Lejeune,
• Abdellatif Bouchalkha,
• Mimoun El Marssi,
• Steevy Cordette,
• Chaouki Kasmi and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2024, 15, 817–829, doi:10.3762/bjnano.15.68

• pollutants is often driven by reactive agents, such as superoxide radicals, hydroxyl radicals, or photo-induced holes produced from either the conduction or valence bands [41][42]. The mechanism of the PD of MB under visible light excitation consists of several steps: Initially, the MB dye molecules are

• adsorbed onto the surface of the catalyst [20], then the illumination with energy greater than that of the bandgap will promote electrons (e−) to the conduction band (CB), leaving holes (h+) in the valence band (VB). Simultaneously, oxygen molecules on the surface of the catalyst capture the excited

• materials while taking into account their bandgap energies, as per the following equations: where ECB is the energy level of the conduction band, EVB is the energy level of the valence band, Eg(x) and X(x) are the bandgap and the electronegativity of the respective material. E0 represents the scaling

Reduced subthreshold swing in a vertical tunnel FET using a low-work-function live metal strip and a low-k material at the drain

• Kalai Selvi Kanagarajan and
• Dhanalakshmi Krishnan Sadhasivan

Beilstein J. Nanotechnol. 2024, 15, 713–718, doi:10.3762/bjnano.15.59

• device is shown in Figure 5 for both the on- and the off-state. Compared to the barrier width in the on-state, the distance between valence band of the source and conduction band of the channel is greater in the off-state (Vgs = Vds = 0). In the on-state, Vgs regulates electron motion. A reduction in

Aero-ZnS prepared by physical vapor transport on three-dimensional networks of sacrificial ZnO microtetrapods

• Veaceslav Ursaki,
• Tudor Braniste,
• Victor Zalamai,
• Emil Rusu,
• Vladimir Ciobanu,
• Vadim Morari,
• Daniel Podgornii,
• Pier Carlo Ricci,
• Rainer Adelung and
• Ion Tiginyanu

Beilstein J. Nanotechnol. 2024, 15, 490–499, doi:10.3762/bjnano.15.44

• region at 3.62 eV is related to a free-to-bound electron transition from a shallow donor to the valence band of ZnS [35]. The other two bands around 2.4 and 2.9–3.0 eV in the deep level defect region are the most common PL bands observed in various ZnS samples and have been associated with DA pair

• 0.6 eV below the conduction band and an acceptor impurity band situated around 0.9 eV above the valence band. Under resonant excitation by the 325 nm laser line, electron–hole pairs are created by intrinsic excitation, and the PL band at 2.9–3.0 eV is a result of free-to-bound transitions of electrons

• materials revealed by XRD and PL spectral analyses (Figure 7) may be beneficial from the point of view of preparing various nanocomposites in a controlled manner, providing opportunities for bandgap engineering. This approach is interesting for the alignment of the conduction and valence bands of the

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

• %). The rate constant of MB degradation decreases to 0.0015 min−1 from 0.0123 min−1. This result indicates that the •OH degradation pathway plays a critical role in the MB photocatalytic degradation. Iodide ions (I−) are strong scavengers that react with valence band holes () [35]. Bromate ions

• photocorrosion and exhibits excellent reusability for the degradation process. The mechanism of MB degradation over the CF/GQDs catalyst is illustrated in Scheme 2. Under visible light irradiation, photogenerated holes (h+) are created in the valence bands via the transfer of photogenerated electrons (e−) from

• the valence band to the conduction band (Equation 1). Hence, photoinduced electron transfer possibly takes place from CF to GQDs, which are excellent acceptors [39] (Equation 2). This retards the recombination of electrons and holes in the nanocomposites [40]. The photoinduced holes are, therefore

Classification and application of metal-based nanoantioxidants in medicine and healthcare

• Nguyen Nhat Nam,
• Nguyen Khoi Song Tran,
• Tan Tai Nguyen,
• Nguyen Ngoc Trai,
• Nguyen Phuong Thuy,
• Hoang Dang Khoa Do,
• Nhu Hoa Thi Tran and
• Kieu The Loan Trinh

Beilstein J. Nanotechnol. 2024, 15, 396–415, doi:10.3762/bjnano.15.36

• activity. Cerium-based nanomaterials exhibit CAT activity through the ability to decompose H2O2 into O2 and H2O. Cerium oxide consists of mixed valence stages of Ce3+ (reduced) and Ce4+ (fully oxidized), which allows for the generation of redox cycles for exhibiting CAT activity in the presence of H2O2

Investigating structural and electronic properties of neutral zinc clusters: a G₀W₀ and G₀W₀Г₀⁽¹⁾ benchmark

• Sunila Bakhsh,
• Muhammad Khalid,
• Sameen Aslam,
• Muhammad Sohail,
• Muhammad Aamir Iqbal,
• Mujtaba Ikram and
• Kareem Morsy

Beilstein J. Nanotechnol. 2024, 15, 310–316, doi:10.3762/bjnano.15.28

• reported these peaks in theory for clusters of n =4, 7, 9, 10, and 14. It can also be seen in Figure 2, that there are two shoulders or peaks, one at n = 4 and the other at n = 10. As zinc has two valence electrons, these peaks correspond to the formation of magic number clusters. Eight and 20 valence

Exploring the relationships between physiochemical properties of nanoparticles and cell damage to combat cancer growth using simple periodic table-based descriptors

• Joyita Roy and
• Kunal Roy

Beilstein J. Nanotechnol. 2024, 15, 297–309, doi:10.3762/bjnano.15.27

• “valence electron potential” (−eV) determines the elements’ reactivity and is based on the charge of the valence electrons and the ionic radius: Here, k is a proportionality factor expressing the energy of the valence electrons in electronvolts. n is the valence, and r is the ionic radius. This descriptor

• negatively contributes to the zeta potential suggesting that with the increase of the valence electron potential of the metal, there will be a decrease in zeta potential value. This has been observed in Mn2O3 NPs, which have a valence electron potential value of 220eV and a zeta potential of −15.9 mV. Co3O3

• NPs show the opposite result; the decrease in the valence electron potential value (38eV) shows an increase in zeta potential value (22.6 mV). MeOx NPs with large ionic radius tend to have low valence electron potential, as it is inversely proportional to the ionic radius of the NPs. NPs with lower

CdSe/ZnS quantum dots as a booster in the active layer of distributed ternary organic photovoltaics

• Gabriela Lewińska,
• Piotr Jeleń,
• Zofia Kucia,
• Maciej Sitarz,
• Łukasz Walczak,
• Bartłomiej Szafraniak,
• Jerzy Sanetra and
• Konstanty W. Marszalek

Beilstein J. Nanotechnol. 2024, 15, 144–156, doi:10.3762/bjnano.15.14

• . Increased molecular order and increasing crystallinity of the system were positively correlated with changes in device performance [51]. Ultraviolet photoelectron spectroscopy We obtained survey spectra for the materials under consideration (Figure 9a,b). Figure 9c illustrates the obtained valence spectrum

• , QD520, QD580, QD600, and QD640, respectively. According to Hummon et al. [52] the CdSe valence-band edge was determined to be −6.8 eV, from thin-film UPS and photoluminescence measurements. The CdSe conduction-band edge was determined by the photonic band gap (2.0–4.8 eV). The valence- and conduction

• diagram of a potential solar cell with aluminum and indium tin oxide (ITO) electrodes is presented in Figure 10. The HOMO was determined using the UPS spectrum of the valence bands for all samples. The lowest unoccupied molecular orbital (LUMO) was determined by subtracting the energy gap from the HOMO