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

• degradation of methylene blue (MB) under visible light. The catalyst can be recycled with an external magnetic field and displays suitable stability. Also, it was reused in three successive experiments with a loss of efficiency of about 5%. The CF/GQDs are considered as an efficient photocatalyst for MB

• 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

• min). (a) Effects of addition of KI, IPA, KBrO3, and BQ on the visible-light-driven photocatalytic degradation of MB with CF@GQDs; (b) dependence of the chemical oxygen demand on the reaction time. (a) Cyclic photocatalytic degradation experiments of MB with CF/GQDs-200 photocatalyst; (b) XRD pattern

Comparative electron microscopy particle sizing of TiO₂ pigments: sample preparation and measurement

• Ralf Theissmann,
• Christopher Drury,
• Markus Rohe,
• Thomas Koch,
• Jochen Winkler and
• Petr Pikal

Beilstein J. Nanotechnol. 2024, 15, 317–332, doi:10.3762/bjnano.15.29

• ) passes through a flat maximum in the pigment MinFeret size range between 110 and 220 nm. Particles with a MinFeret well below 100 nm have limited capability to scatter visible light, resulting in poorer tinting strength, and are consequently inefficient as pigments. The CIE b* values depict the ability

• practical and reliable way of verifying EM results for nearly spherical, non-porous, and non-aggregated particles without rugged surface treatment, even if they have been prepared by different methods. Pigmentary TiO2 must have a specific particle size range to scatter visible light effectively. The

• . In the case of TiO2 with a refractive index of 2.5–2.9 (depending on the crystal structure), the optimum particle size for visible light scattering is around 200 nm [12]. Particles of this size scatter mostly red and green light, so the tint of such material is yellow. If a bluer shade is required, a

A visible-light photodetector based on heterojunctions between CuO nanoparticles and ZnO nanorods

• Doan Nhat Giang,
• Nhat Minh Nguyen,
• Duc Anh Ngo,
• Thanh Trang Tran,
• Le Thai Duy,
• Cong Khanh Tran,
• Thi Thanh Van Tran,
• Phan Phuong Ha La and
• Vinh Quang Dang

Beilstein J. Nanotechnol. 2023, 14, 1018–1027, doi:10.3762/bjnano.14.84

• nanoparticles and ZnO nanorods obtained via a simple and cost-effective synthesis process has great potential for optoelectronic applications. Keywords: CuO nanoparticles; heterojunction; optoelectronics; visible-light photodetector; ZnO nanorods; Introduction Optoelectronics is a field to accelerate the

• a particular wavelength [9][10][11][12][13][14] and broadband PDs that work over a wide wavelength range [15]. Many researchers have focused on developing sensing materials operating in the visible-light region because this region is the biggest fraction of the solar spectrum (around 43%) [16][17

• [21]. Regardless, pure ZnO still has the considerable drawback of a wide bandgap (ca. 3.35 eV), which limits its usability for visible-light photodetectors. ZnO absorbs light only in the UV region (less than 4% of the sunlight spectrum) [23]. Extending the operation range of ZnO nanomaterials toward

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

• development of advanced materials based on semiconductors (i.e., carbon-modified hexagonal boron nitride (MBN), MgO@g-C3N4, and TiO2@MWCNTs) have indicated a highly efficient photocatalytic performance for phenol removal using a low-power visible LED light source. For NO degradation, a visible light source

Mixed oxides with corundum-type structure obtained from recycling can seals as paint pigments: color stability

• Dienifer F. L. Horsth,
• Julia de O. Primo,
• Nayara Balaba,
• Fauze J. Anaissi and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2023, 14, 467–477, doi:10.3762/bjnano.14.37

• ) coloration of the mixed oxides was confirmed by XPS and visible-light absorption measurements. The colorimetric stability of the oxides in acid and alkaline environments was evaluated. After 240 h of exposure to harsh environments, both pigments demonstrated stability and showed no strong color difference

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

• produced the homogeneous formation of the APDA layer on the wood surface. The APDA-coated wood sample efficiently absorbed UV–visible light to more than 96%. In addition, the NIR absorption efficiency was also improved to more than 87% (Figure 8c). SSG structure In order to obtain a high vaporization

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

• incident radiation from the sun, 8% UV, 42.4% visible light, and 49.6% infrared radiation reach the earth's surface. Applications such as steam generation from solar power can evidently benefit from the use of materials that can absorb as much as possible of the entire spectrum of solar radiation. In this

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

• ultraviolet light in the solar spectrum due to its broad bandgap of 3.2 eV, which limits the use of visible light. Because of this, the potential photocatalytic use of TiO2 is constrained and the photocatalytic effectiveness is reduced [19][20][25]. Table 1 compares some of the salient characteristics of some

• , nanometre-sized photocatalysts based on bismuth have recently been investigated and evaluated, because the majority of bismuth-based photocatalysts have a bandgap below 3.0 eV, making them usable in visible light. Additionally, their electrical structure produces a valence band with hybrid O 2p and Bi 6s

• . Different materials based on bismuth have been developed and used for a range of environmental remediation applications. For instance, Mu et al. [46] synthesised a Bi2S3/Bi4O7 heterostructure via an in situ sulfidation approach and utilised it for the degradation of rhodamine B dye under visible-light

Cyclodextrins as eminent constituents in nanoarchitectonics for drug delivery systems

• Makoto Komiyama

Beilstein J. Nanotechnol. 2023, 14, 218–232, doi:10.3762/bjnano.14.21

• opened for the release of encapsulated drug. In order to achieve photoinduced drug release through visible light, tetra-ortho-methoxy-substituted azobenzene (mAzo) can be used instead of unsubstituted azobenzene. The trans-to-cis isomerization of this chromophore proceeds under irradiation with red or

• green light, and the reverse cis-to-trans isomerization occurs under blue light [50]. Compared with UV light, visible light is advantageous for medical applications, since it can penetrate more deeply into tissues and causes less photodamage to healthy cells. In the same way as unsubstituted azobenzene

• ) light is more advantageous than UV and visible light, since it penetrates more efficiently into tissues, and the toxicity is marginal. However, most photoisomerizable dyes (azobenzenes and arylazopyrazoles) require UV or visible light and are incompatible with NIR. The most straightforward strategy is

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

• and thermally stable, quasi-spherical, photoluminescent material with very good antibacterial and anticancer properties under visible light irradiation [9][10][11][12][13][14][15][16]. This material has very good biocompatibility, including low dark cytotoxicity and good cell proliferation

• (nitrogen, chlorine, and fluorine) affected structural properties and ROS production with or without visible light irradiation. In addition, we examined antibacterial and cytotoxic properties. An important issue is the preparation of CQDs and polymer-based composites and their possible antibacterial

• toluene solution of CQDs has a strong broad absorption band at 248 nm with a shoulder at 224 nm, which represents the π–π* transition of C=C bonds. Apart from this broad band, there is a shoulder peak at 330 nm corresponding to the n–π* transition of C=O [32]. In the visible light region, at 444 nm, there

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

• O–H bonds, which are caused by air humidity. To confirm the ability of the heterojunctions to enhance absorption in the visible-light region, the DRS spectra and Tauc plots were recorded and are presented in Figure 4. It can be easily observed in Figure 4a that the TNAs show a strong absorption edge

• at 393 nm. This means that TNAs are only activated by near-UV irradiation. In contrast, the g-C3N4 sample shows an absorption edge at 464 nm. Meanwhile, MoS2 exhibits strong absorption from the UV region extending to the entire visible-light region. It can be seen that the loading of both MoS2 and g

• -C3N4 on the TNAs surface extended the absorption to the visible-light range. Specifically, the absorption edge of the g-C3N4/TNAs and MoS2/TNAs samples shifted to 442 and 425 nm, respectively. Besides, a remarkable feature of the DRS spectrum of MoS2 is a superior absorption ability in the whole

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

• -scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and linear sweep voltammetry. The results show that the TiO2@MWCNTs nanocomposite has an optical bandgap of 2.5 eV, which is a significant improvement in visible-light absorption capability compared to TiO2 (3.14 eV). The

• mesoscale TiO2 [2][3]. This results in an improvement of the photon efficiency of TiO2 nanoparticles. Reducing the dimension of the photocatalyst favors not only a bandgap shift to the visible-light region but, unfortunately, also the recombination of photogenerated electrons and holes (e−/h+), which limits

• been developed to increase the absorption of visible solar light [6][7]. Notably, carbon nanotubes (CNTs) are a promising material for visible-light absorption [8]. A combination of TiO2 with CNTs can effectively enhance the separation of e−/h+ pairs based on the high electric conductivity of CNTs

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

• -photoresponsive hexagonal boron nitride (HBN) into a visible-light-responsive material. The carbon modification was achieved through a solid-state reaction procedure inside a tube furnace under nitrogen atmosphere. In comparison to HBN (bandgap of 5.2 eV), the carbon-modified boron nitride could efficiently

• absorb LED light irradiation with a light harvesting efficiency of ≈90% and a direct bandgap of 2 eV. The introduction of carbon into the HBN lattice led to a significant change in the electronic environment through the formation of C–B and C–N bonds which resulted in improved visible light activity

• , respectively. The setup consists of a 0.5 M Na2SO4 electrolyte/hole-scavenger solution along with LED lamps as a visible light source. The working electrode was fabricated through an ITO-PTFE electrode (dimensions: 1 cm × 1 cm) drop casted with a slurry of the studied materials, isopropanol and Nafion solution

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

• environmental restoration and energy conversion is photocatalysis powered by solar light. Traditional photocatalysts have limited practical uses due to inadequate light absorption, charge separation, and unknown reaction mechanisms. Discovering new visible-light photocatalysts and investigating their

• modification is crucial in photocatalysis. Bi-based photocatalytic nanomaterials have gotten much interest as they exhibit distinctive geometric shapes, flexible electronic structures, and good photocatalytic performance under visible light. They can be employed as stand-alone photocatalysts for pollution

• , and SrTiO3), sulfates (e.g., MoS2 and Bi2S3), selenides (e.g., MoSe2 and CdSe), and phosphates (e.g., Ag3PO4) [8][9][10][11][12][13][14][15]. The bandgap of photocatalysts sensitive to visible light is smaller than 3 eV. Wide-bandgap photocatalysts can only be stimulated by ultraviolet light, which

A super-oscillatory step-zoom metalens for visible light

• Yi Zhou,
• Chao Yan,
• Peng Tian,
• Zhu Li,
• Yu He,
• Bin Fan,
• Zhiyong Wang,
• Yao Deng and
• Dongliang Tang

Beilstein J. Nanotechnol. 2022, 13, 1220–1227, doi:10.3762/bjnano.13.101

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

• environment, human health, and other biotas. Among the technologies to treat NO pollution, photocatalytic oxidation under visible light is considered an effective means. This study describes photocatalytic oxidation to degrade NO under visible light with the support of a photocatalyst. MgO@g-C3N4

• heterojunction photocatalysts were synthesized by one-step pyrolysis of MgO and urea at 550 °C for two hours. The photocatalytic NO removal efficiency of the MgO@g-C3N4 heterojunctions was significantly improved and reached a maximum value of 75.4% under visible light irradiation. Differential reflectance

• simple way to synthesize photocatalytic heterojunction materials with high reusability and the potential of heterojunction photocatalysts in the field of environmental remediation. Keywords: g-C3N4; MgO; nitric oxide; photocatalyst; visible light; Introduction The rapid development of industrialization

Green synthesis of zinc oxide nanoparticles toward highly efficient photocatalysis and antibacterial application

• Vo Thi Thu Nhu,
• Nguyen Duy Dat,
• Le-Minh Tam and
• Nguyen Hoang Phuong

Beilstein J. Nanotechnol. 2022, 13, 1108–1119, doi:10.3762/bjnano.13.94

• that the prepared ZnO material excellently removed MB and MO (cinitial = 10 mg/L) with efficiencies of 100% and 82.78%, respectively, after 210 min under UV radiation with a ZnO NP dose of 2 g/L. The photocatalyst activity of the synthesized material was also tested under visible light radiation with

• under UV light was higher than that under visible light. The degradation of MB (10 mg/L) under visible and UV light by ZnO NPs was 50.46% and 100%, respectively, after 210 min of irradiation. The degradation efficiency of MO (10 mg/L) by ZnO was lower than that of MB (10 mg/L). After 210 min of

• irradiation by visible and UV light, the MO degradation efficiency by ZnO NPs reached 33.56 and 82.78%, respectively. ZnO has a rather high bandgap energy; therefore, the degradation efficiency of organic substances under visible light is not as high as that under UV light. Maddu et al. [34] studied the

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

• cavities, and excellent thermal stability [20][21]. These advantages make it appalling to adsorption [22], gaseous capture/separation [23], sensing [24], and drug release applications [25]. Moreover, some MOFs can be excited under UV or visible light and exhibit light harvesting properties due to ligand

• iron and bridged terephthalic acid molecules. It has high hydrothermal stability, low cost, good hydrophilicity, non-toxicity, and environmental friendliness [20][34]. Most importantly, MIL101(Fe) contains abundant iron-oxo (Fe-O) clusters, which makes it a photocatalyst with visible-light response [19

• use carbon nanotubes or carbon quantum dots to modify MIL101(Fe) to enhance its conductivity and broaden its visible-light response [37][38]. Another strategy is to construct MIL101-based heterostructures with the aid of narrow-gap semiconductors to promote the separation and transfer of

Solar-light-driven LaFe_xNi_1−xO₃ perovskite oxides for photocatalytic Fenton-like reaction to degrade organic pollutants

• Chao-Wei Huang,
• Shu-Yu Hsu,
• Jun-Han Lin,
• Yun Jhou,
• Wei-Yu Chen,
• Kun-Yi Andrew Lin,
• Yu-Tang Lin and
• Van-Huy Nguyen

Beilstein J. Nanotechnol. 2022, 13, 882–895, doi:10.3762/bjnano.13.79

• Fenton reaction, a photo-Fenton reaction excited by ultraviolet light or visible light can achieve a faster reaction rate and a complete degree of oxidation [19]. Besides, it shows a positive relationship between light intensity and photocatalytic activity. With the assistance of light irradiation, the

• nanoparticles via the sol–gel method to decompose rhodamine-B under visible light irradiation. With the assistance of H2O2, it shows a synergistic effect between photocatalytic reaction and heterogeneous photo-Fenton-like reaction [23]. Furthermore, the strategies of being loaded over supports (such as g-C3N4

• , methylene blue, and rhodamine B under visible light irradiation. Their optimal sample was LaFe0.85Cu0.15O3, which could remove dyes much more efficiently due to more generation of hydroxyl radicals than pure LaFeO3 [31]. Ni-doped LaFeO3 was ubiquitously employed as a photo/thermal catalyst or a catalyst

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

• nanotubes were formed by TiO2 nanotubes that uniformly anchored with Bi2WO6 nanoparticles of various densities on the surface. The composites exhibited improved photocatalytic activities toward the reduction of Cr(VI) and degradation of rhodamine B under visible light (λ > 420 nm), which were attributed to

• visible light together with an accelerated separation and transfer of the photogenerated electron–hole pairs of the nanocomposites, which resulted in increased effective amounts of photogenerated carriers for the photocatalytic reactions. It was demonstrated that the photoinduced electrons dominated the

• ][8]. However, the wide bandgap of TiO2 inhibits the absorption of light in the visible region and the rapid recombination of photogenerated electron−hole pairs restrains its photocatalytic activity. It has been verified that constructing TiO2-based heterostructured composites by using visible-light

Sodium doping in brookite TiO₂ enhances its photocatalytic activity

• Boxiang Zhuang,
• Honglong Shi,
• Honglei Zhang and
• Zeqian Zhang

Beilstein J. Nanotechnol. 2022, 13, 599–609, doi:10.3762/bjnano.13.52

• exceeded four times that of P25 under visible light irradiation [8]. The degradation of methyl orange by brookite nanoflowers was much more efficient than that by anatase nanorods [9]. Moreover, the heterojunction of brookite TiO2 can enhance the photocatalytic activity (e.g., the rutile/brookite TiO2

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

• (ZnO) and the metal. [71] showed that ZnO NRs with Ag-based substrates presented an enhancement of the Raman signal by acquiring a charge equilibration between the Fermi level of the metal and the CB of the ZnO. Excitation with visible light led to the following mechanism (Figure 4): The electrons from

• applications for optoelectronic devices, namely light-emitting diodes for both UV and visible light [89]. Also, the combination with metallic nanoparticles has been proposed for enhanced UV light-emitting diodes [90]. Another significant application of ZnO-based substrates is to boost the performance of dye

Engineered titania nanomaterials in advanced clinical applications

• Padmavati Sahare,
• Paulina Govea Alvarez,
• Juan Manual Sanchez Yanez,
• Gabriel Luna-Bárcenas,
• Samik Chakraborty,
• Sujay Paul and
• Miriam Estevez

Beilstein J. Nanotechnol. 2022, 13, 201–218, doi:10.3762/bjnano.13.15

• TiO2 nps [83]. TiO2 supported on silica nanospheres was checked for its antibacterial activity against E. coli, and the result demonstrated a more effective growth inhibition than that of commercial TiO2-P25 under ultraviolet and visible light [84]. Copper is well known for its antimicrobial properties

A comprehensive review on electrospun nanohybrid membranes for wastewater treatment

• Senuri Kumarage,
• Imalka Munaweera and
• Nilwala Kottegoda

Beilstein J. Nanotechnol. 2022, 13, 137–159, doi:10.3762/bjnano.13.10

A photonic crystal material for the online detection of nonpolar hydrocarbon vapors

• Evgenii S. Bolshakov,
• Aleksander V. Ivanov,
• Andrei A. Kozlov,
• Anton S. Aksenov,
• Elena V. Isanbaeva,
• Sergei E. Kushnir,
• Aleksei D. Yapryntsev,
• Aleksander E. Baranchikov and
• Yury A. Zolotov

Beilstein J. Nanotechnol. 2022, 13, 127–136, doi:10.3762/bjnano.13.9

• polymer regarding material strength. Method Figure 8a shows the scheme of the experimental equipment. It consists of the spectrophotometer “eye-one Pro” and a peripheral device, which is made of black composite material based on epoxy resins for visible-light absorption and to elude backward reflection