Microplastic pollution in Himalayan lakes: assessment, risks, and sustainable remediation strategies

• Sameeksha Rawat,
• S. M. Tauseef and
• Madhuben Sharma

Beilstein J. Nanotechnol. 2025, 16, 2144–2167, doi:10.3762/bjnano.16.148

• simultaneously utilizing the abundant UV radiation [75]. It has been demonstrated that the light absorption of ZnO and TiO2 is improved by defect engineering, such as the introduction of oxygen vacancies. According to Kim and Youn, these defects trap light energy, which lowers charge carrier recombination rates

Piezoelectricity of layered double hydroxides: perspectives regarding piezocatalysis and nanogenerators

• Evgeniy S. Seliverstov,
• Evgeniya A. Tarasenko and
• Olga E. Lebedeva

Beilstein J. Nanotechnol. 2025, 16, 1812–1817, doi:10.3762/bjnano.16.124

• evidence demonstrated that dual oxygen vacancies in Ni/Fe-LDHs create interfacial bonds that mitigate carrier localization effects and unfavorable influences during piezocatalysis and photocatalysis. These features promote exciton dissociation and charge transfer. Furthermore, the strong electronic

• instead arise from triboelectric, electrochemical, or mechanochemical contributions. (2) Confusion of mechanisms: Different studies attribute performance improvements either to symmetry breaking (ultrathin LDH, loss of inversion centers, piezoelectrical properties), to defects (oxygen vacancies and

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

• , the content of hydroxyl groups in CC/HTNW is evaluated to be ca. 52%, which reduced to approximately 16% after the final air calcination, suggesting abundant residual surface oxygen vacancies in CC/NW-450 °C. These vacancies are beneficial for enhancing photocatalytic activity [26][27]. Photocatalytic

Laser processing in liquids: insights into nanocolloid generation and thin film integration for energy, photonic, and sensing applications

• Akshana Parameswaran Sreekala,
• Pooja Raveendran Nair,
• Jithin Kundalam Kadavath,
• Bindu Krishnan,
• David Avellaneda Avellaneda,
• M. R. Anantharaman and
• Sadasivan Shaji

Beilstein J. Nanotechnol. 2025, 16, 1428–1498, doi:10.3762/bjnano.16.104

Enhancing the photoelectrochemical performance of BiOI-derived BiVO₄ films by controlled-intensity current electrodeposition

• Huu Phuc Dang,
• Khanh Quang Nguyen,
• Nguyen Thi Mai Tho and
• Tran Le

Beilstein J. Nanotechnol. 2025, 16, 1289–1301, doi:10.3762/bjnano.16.94

• improvements through stronger peaks, suggesting fewer defects. The decrease in the bandgap (≈0.16 eV) is consistent with research linking oxygen vacancies to band tailing in BiVO4 films [26]. Besides, Figure 3a shows that the BiVO4(326) and BiVO4(324) samples have absorption that goes beyond 520 nm, with some

• suggests an optimal concentration of oxygen vacancies that broadens light absorption while avoiding excessive recombination of the charge carriers. In contrast, BiVO4(146) has a clear absorption edge and very little tailing, indicating that it has fewer defects but does not absorb light well beyond 520 nm

• . These findings match other studies that connect oxygen vacancies to the spread of light absorption and smaller optical bandgaps in BiVO4 [26]. Vibrational properties (Raman) The Raman spectra (Figure 4) corroborated the XRD findings, displaying characteristic peaks of monoclinic BiVO4 at 219, 329, 370

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

• optical phonon modes is ascribed to the formation of oxygen vacancies, which are supposed to be electron carriers in ZnO. Therefore, the evolution of the A1 (LO) mode acts as indirect evidence of a rise in carrier concentration, which can in turn alter the optical bandgap. Moreover, the presence of

•  4a). The A1 (LO) mode evolves because of defects present in the film in the form of oxygen vacancies, zinc interstitials, and their complexes. For the case of ZnO films implanted at 1 × 1015 ions·cm−2 fluence (Figure 4b), the intensity of the E2 (low) and A1 (LO) modes increases, while the peak

• . [14] have also reported such behavior of the A1 (LO) Raman mode in 300 keV argon ion-implanted ZnO films. Mondal et al. [29] and Li et al. [30] have ascribed these peaks centered at 577 and 554 cm−1 to oxygen vacancies and zinc interstitials, respectively. Moreover, the peak related to the A1 (LO

Retrieval of B1 phase from high-pressure B2 phase for CdO nanoparticles by electronic excitations in Cd_xZn_1−xO composite thin films

• Arkaprava Das,
• Marcin Zając and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2025, 16, 551–560, doi:10.3762/bjnano.16.43

• of the O K edge spectrum. This attenuation suggests that O ion irradiation diminishes the likelihood of core-level electronic transitions from O 1s to the hybridized Zn 4s–O 2p orbitals. It is plausible that O ion irradiation generates oxygen vacancies (VO) at lattice sites and introduces defects

Quantification of lead through rod-shaped silver-doped zinc oxide nanoparticles using an electrochemical approach

• Ravinder Lamba,
• Gaurav Bhanjana,
• Neeraj Dilbaghi,
• Vivek Gupta and
• Sandeep Kumar

Beilstein J. Nanotechnol. 2025, 16, 422–434, doi:10.3762/bjnano.16.33

• of oxygen on the surface by means of the formation of oxygen vacancies, leading to enhanced catalytic activity. Also, the small doping of Ag introduces more active sites on the catalyst surface, potentially improving the overall catalytic activity [12][13]. This study demonstrates an efficient and

• region of the Brillouin zone. Oxygen vacancies are commonly linked to the A1(LO) phonon mode. The presence of a small peak at 218 cm−1 denotes the radial movement of Ag atoms. Raman peaks at around 356 cm−1 are specifically attributed to the A1(TO) mode. Also, the results of Ag doping in ZnO coincide

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

• recombination rates, and the generated oxygen vacancies, ultimately enhancing catalytic efficiency in visible light or solar-simulated light. The durability of the modified TiO2 relied on the number of electrons in the dopants and their ionic size. Although researchers have significantly improved the catalytic

• photocatalyst [74]. In a recent study, Jeyaprakash and coworkers [75] synthesized Ti3+-doped TiO2 with oxygen vacancies utilizing ultrasonic treatment for the degradation of tetracycline (TC) via sono-photocatalysis under visible halogen lamp irradiation. The modified TiO2 demonstrated remarkable degradation of

Mn-doped ZnO nanopowders prepared by sol–gel and microwave-assisted sol–gel methods and their photocatalytic properties

• Cristina Maria Vlăduț,
• Crina Anastasescu,
• Silviu Preda,
• Oana Catalina Mocioiu,
• Simona Petrescu,
• Jeanina Pandele-Cusu,
• Dana Culita,
• Veronica Bratan,
• Ioan Balint and
• Maria Zaharescu

Beilstein J. Nanotechnol. 2024, 15, 1283–1296, doi:10.3762/bjnano.15.104

• activity of the modified nanomaterials can be modulated by the dopant concentration. Figure 9 shows for both investigated samples a main emission peak at 420 nm and a smaller one at 480 nm. According to the literature data, both maxima correspond to the excitonic PL related to surface oxygen vacancies and

• signal of the SG sample (assigned to surface oxygen vacancies and defects) and can be further analyzed taking into account the photocatalytic test results. Photocatalytic activity Oxidative photodegradation of oxalic acid in aqueous solution (Figure 13) was used to compare the catalytic activity of the

Effect of repeating hydrothermal growth processes and rapid thermal annealing on CuO thin film properties

• Monika Ozga,
• Eunika Zielony,
• Aleksandra Wierzbicka,
• Anna Wolska,
• Marcin Klepka,
• Marek Godlewski,
• Bogdan J. Kowalski and
• Bartłomiej S. Witkowski

Beilstein J. Nanotechnol. 2024, 15, 743–754, doi:10.3762/bjnano.15.62

• structural properties and elemental composition among the 1×, 2×, and 3× samples. Hence, it is believed that the most probable cause for the increasing work function value is the annealing atmosphere of the samples (O2/N2, 1:1) [66]. The presence of oxygen in the annealing atmosphere fills the oxygen

• vacancies present in the material, consequently leading to an elevation in the work function value. The combination of O2 and N2 was chosen over pure oxygen because of cost-effectiveness. At the same time, efforts were made to ensure that the selected annealing atmosphere was closer to the composition of

Elastic modulus of β-Ga₂O₃ nanowires measured by resonance and three-point bending techniques

• Annamarija Trausa,
• Sven Oras,
• Sergei Vlassov,
• Mikk Antsov,
• Tauno Tiirats,
• Andreas Kyritsakis,
• Boris Polyakov and
• Edgars Butanovs

Beilstein J. Nanotechnol. 2024, 15, 704–712, doi:10.3762/bjnano.15.58

• error simulations of the geometry uncertainty indicate that a ±25 nm width error (SEM method) and ±15 nm height error (AFM method) for NWs with 100 nm width/height corresponds to the observed scattering in elastic modulus values in Figure 4. Finally, point defects, such as oxygen vacancies, can increase

• the average bond length and thus result in a reduction in the elastic modulus [31][32][33]. For example, Wang et al. [34] showed that ZnO NWs with a higher density of oxygen vacancies, inferred from photoluminescence measurements, exhibited significantly (up to 20%) lower Young’s modulus. Wang et al

• . [35] measured a lower (up to 16%) elastic modulus for Al2O3 NBs in comparison to the theoretical value and attributed this difference to oxygen vacancies within NBs. As per our previous study [36], our as-grown Ga2O3 NWs exhibit a strong photoluminescence band related to oxygen vacancies, indicating a

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

• processes, including those related to oxygen species adsorbed by the huge surface of the aeromaterial, as previously observed in ZnS nanostructures [42]. Some of these states may be related to oxygen vacancies and complex centers. Under ambient conditions, some oxygen species from the air are adsorbed at

• the surface states, forming complexes with oxygen vacancies. These complexes may be responsible for the PL band around 2.4 eV. Under vacuum conditions, the oxygen species are desorbed from the surface, annihilating the formed complexes. As a result, the intensity of the PL band around 2.4 eV decreases

• [43]. The adsorption of oxygen species from the environment on the sample surface promoted by oxygen vacancies results also in a strong interaction between the photoexcited electrons captured by oxygen vacancies and the adsorbed oxygen species. The formation of the SnO2 phase in the prepared aero-ZnS

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

• ]. The heterostructures increase surface electron deficiency, redox couples, and oxygen vacancies through an intrinsic electric field and lattice mismatch at the metal–semiconductor interface. Thus, a high level of oxygen vacancies enhances the adsorption and activation of oxygen-containing ROS, that is

• higher Ce4+ content are known to have higher CAT activity, while cerium nanomaterials with greater Ce3+ content enhance SOD activity. It was reported that Ce3+ has more oxygen vacancies providing more active sites for the binding of superoxide radicals on the surface [77][78][79]. By controlling the Ce3

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

• revealed from the XRD studies, as-deposited NS-WOx films are amorphous in nature, whereas post-growth vacuum-annealed (at 673 K for 1 h) films show an amorphous-to-crystalline structural phase transition. XPS analysis confirms an increasing concentration of defect density in the form of oxygen vacancies

• conduction across the heterojunction with increasing film thickness indicates a possible role of oxygen vacancies in facilitating smooth charge transport till the thickness reaches 30 nm, above which the series resistance effect within the WOx film starts to dominate. Overall, this study demonstrates a wide

The microstrain-accompanied structural phase transition from h-MoO₃ to α-MoO₃ investigated by in situ X-ray diffraction

• Zeqian Zhang,
• Honglong Shi,
• Boxiang Zhuang,
• Minting Luo and
• Zhenfei Hu

Beilstein J. Nanotechnol. 2023, 14, 692–700, doi:10.3762/bjnano.14.55

• from +2 to +6 [1][2], leading to a range of molybdenum oxides. Molybdenum oxides include the fully stoichiometric MoO3 with a large bandgap above 2.7 eV, the reduced oxides MoO3−x with oxygen vacancies, and the semimetal MoO2. The degree of reduction influences the bandgap energy of molybdenum oxides

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

• indicate changes regarding the variation of the nanoparticle surfaces according to the value of the working pressure. Since XPS analysis is a surface measurement and the samples were calcined in air, the possibility to identify the presence of Ti3+ species and oxygen vacancies is small, but we do not

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

• ][104][110][144][145][146][147][148][149][150]. Doping reduces the bandgap energy, introduces intermediate energy levels to overcome constraints, creates trap sites to capture photogenerated charge carriers, and increases the absorption of visible light. Additionally, after doping, oxygen vacancies or

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

• transforms into rutile. This could be due to the carbon components on the MWCNTs acting as a robust reducing agent for facilitating the transformation from anatase to rutile TiO2 by forming oxygen vacancies [30]. Generally, the capacitance of the photoelectrochemical electrode is associated with the

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

• type of halogen used. The activation of otherwise inert CO2 and H2O molecules is greatly aided by the ease with which photoinduced oxygen vacancies (OVs) are produced on the surface [25]. The excellent photocatalytic performance can be attributed to the layered crystal structures and small bandgap

• sample synthesized at pH 4 demonstrated outstanding visible-light photocatalytic performance regarding the degradation of RhB. This was due to the low thickness, exposed (001) facets, and an appropriate number of oxygen vacancies. This work proposed that revolutionary photoexcitation mechanisms were

• found on oxygen vacancies. Irradiation with visible light excites the electrons in the VB to transition into defect states. In addition, photogenerated defect states cannot readily recombine with photogenerated holes because oxygen vacancies operate as electron traps. Because of this, electrons trapped

Theoretical investigations of oxygen vacancy effects in nickel-doped zirconia from ab initio XANES spectroscopy at the oxygen K-edge

• Dick Hartmann Douma,
• Lodvert Tchibota Poaty,
• Alessio Lamperti,
• Stéphane Kenmoe,
• Abdulrafiu Tunde Raji,
• Alberto Debernardi and
• Bernard M’Passi-Mabiala

Beilstein J. Nanotechnol. 2022, 13, 975–985, doi:10.3762/bjnano.13.85

• is due to the structural disorder induced by the 2Ni dopants and the O vacancies. Furthermore, the analysis of the XANES signatures shows that the oxidation state of nickel atoms changes with the introduction of oxygen vacancies. Our study therefore shows a possibility to control the oxidation state

• large set of DMO. It is thus important to investigate other types of dopants in DMO or other types of oxide matrices doped with transition metals. Oxygen vacancies play a fundamental role in the aforementioned microscopic mechanisms since an excess or lack of oxygen vacancies with respect to their

• TM atom usually occupies the Zr site substitutionally. However, due to the difference in the oxidation state of the TM atom and Zr, oxygen vacancies are created to maintain an overall charge neutrality. This is aptly demonstrated in the experimental investigations of Fe-doped zirconia using X-ray

Hierarchical Bi₂WO₆/TiO₂-nanotube composites derived from natural cellulose for visible-light photocatalytic treatment of pollutants

• Zehao Lin,
• Zhan Yang and
• Jianguo Huang

Beilstein J. Nanotechnol. 2022, 13, 745–762, doi:10.3762/bjnano.13.66

• three weak peaks at 448, 479, and 490 nm, which are indexed to the recombination of photoinduced electron−hole pairs, freely excited electrons, surface defects, and oxygen vacancies on the band edges, respectively [36][61]. It is apparent that the PL intensities of the Bi2WO6/TiO2-NT nanocomposites at

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

• a long time. It was assumed that zinc vacancies, oxygen vacancies, and other defects are candidates for recombination centres involved in the visible luminescence [78]. Studies concerning the green luminescence of ZnO in the past few years assumed that the oxygen vacancies are the most likely

• candidates for recombination centres involved in the visible luminescence of ZnO [77][79]. Thus, the electrical and luminescence characteristics of zinc oxide could be changed by the number of oxygen vacancies or other point defects (vacancies, atom substitutions, and interstitial atoms). Moreover

• also benefits the SERS enhancement. Doping zinc oxide–Ag nanoparticles with magnesium also introduces defect sites (surface defects and oxygen vacancies), which form new energy levels below the conduction band of zinc oxide, facilitating the charge transfer mechanism. In this case, besides the charge

Measurement of polarization effects in dual-phase ceria-based oxygen permeation membranes using Kelvin probe force microscopy

• Kerstin Neuhaus,
• Christina Schmidt,
• Liudmila Fischer,
• Wilhelm Albert Meulenberg,
• Ke Ran,
• Joachim Mayer and
• Stefan Baumann

Beilstein J. Nanotechnol. 2021, 12, 1380–1391, doi:10.3762/bjnano.12.102

• time dependence was shown to vary with dopant concentration (e.g., abundance of oxygen vacancies in ceria) and also depends on the ratio of grain boundary/grain bulk [22][23][24][25]. Single ceria grains in a mixed ion/electron-conductive composite have so far not been addressed by AFM-based

• in this study strongly depended on the surrounding. In single-phase ceria materials, oxygen is incorporated into oxygen vacancies in the structure at high temperatures [4][30]: Previous studies showed that at temperatures below 400 °C the concentration of defect associates in ceria increases because

• electrons are trapped at oxygen vacancy sites, allowing also for singly charged () or uncharged (VO) oxygen vacancies in close vicinity to Ce3+ ions [31][32], which show a strongly lowered mobility. For low temperatures, the common electroneutrality equation for acceptor-doped ceria can be shortened, as