Compact TiO2 films with sandwiched Ag nanoparticles as electron-collecting layer in planar type perovskite solar cells: improvement in efficiency and stability

Fabrication of perovskite solar cells (PSCs) in a simple way with high efficiency and stability remains a challenge. In this study, silver nanoparticles (Ag NPs) were sandwiched between two compact TiO₂ layers through a facile process of spin-coating an ethanolic AgNO₃ solution, followed by thermal annealing. The presence of Ag NPs in the electron-transporting layer of TiO₂ improved the light input to the device, the morphology of the perovskite film prepared on top, and eliminated leakage current. Photoluminescence and electron mobility studies revealed that the incorporation of Ag NPs in the ETL of the planar PSC device facilitated the electron–hole separation and promoted charge extraction and transport from perovskite to ETL. Hysteresis-free devices with incorporated Ag NPs gave a high average short-circuit current density (J_sc) of 22.91 ± 0.39 mA cm⁻² and maximum power conversion efficiency of 17.25%. The devices also showed enhanced stability versus a control device without embedded Ag NPs. The possible reasons for the improvement are analyzed and discussed.

Embedding silver nanoparticles in the compact TiO₂ layer effectively improves the efficiency and stability of a perovskite solar cell.     

Anions influence the extraction of rutile nanoparticles from synthetic and lake water

Due to their recent widespread use, nanoparticles (NPs) may contaminate water sources and pose a health risk. Thus, it is important to understand the fate of NPs in order to evaluate potential threats. Here we show that the presence of anions influences the stability of NPs in synthetic and lake water. Concentrations of 0.3 and 3 mM PO₄³⁻ exhibited stronger stabilizing effects on NPs than 30 mM. Moreover, chloride ions promoted the coagulation of TiO₂ NPs over a range of concentrations (0.3–30 mM elicited similar effects). On the other hand, phosphate was found to hinder the coagulation effect. These results are expected to contribute to novel water purification strategies for the efficient removal of NPs. Further experiments should focus on the mechanism of phosphate on the removal of NPs in the coagulation/flocculation/sedimentation (C/F/S) process.

Different kinds of anions may influence the dispersion stability of nanoparticles in the manner of inner-sphere complexation or outer-sphere complexation.     

Polylactic acid based Janus membranes with asymmetric wettability for directional moisture transport with enhanced UV protective capabilities

Efficient directional moisture transport can remove excess sweat away from the human body and keep the body dry; fully utilizing this functionality to improve the wearing experience is urgently needed in the area of functional textiles. Herein, a facile strategy is used to design an eco-friendly and biodegradable PLA membrane with enhanced directional moisture transport and UV protection abilities. The PLA-based Janus membrane with asymmetric wettability is fabricated via sol–gel and electrospinning methods. Titanium dioxide nanoparticles (TiO₂) were anchored onto the surface of the PLA fabric during the TiO₂ sol–gel fabrication process using polydopamine, forming superhydrophilic TiO₂@PDA–PLA. Then a thin PLA fibrous membrane layer showing hydrophobicity was electrospun onto this (PLA-E). The Janus PLA-E/TiO₂@PDA–PLA membrane was successfully fabricated. Due to the asymmetric wettability and anchored TiO₂, the PLA-E/TiO₂@PDA–PLA Janus membrane exhibits efficient directional moisture transport and excellent UV protection abilities, and this work may provide a new pathway for fabricating multifunctional personal protective materials and have attractive potential applications in the future.

The PLA-E/TiO₂@PDA–PLA Janus membrane with asymmetric wettability exhibits efficient directional moisture transport and excellent UV protective capacity.     

Controllable in situ growth of novel octahedral TiO2 nanoparticles on nickel/titanium alloy fiber substrate for selective solid-phase microextraction of ultraviolet filters in water samples

The nature and fabrication of fiber coatings with good adsorption capacity and selectivity play a decisive role in solid-phase microextraction (SPME). In this work, a novel SPME fiber was fabricated through hydrothermal in situ growth of octahedral TiO₂ nanoparticles (TiO₂NPs) on a superelastic nickel/titanium alloy (NiTi) wire substrate in acid solution. The resulting fiber coatings were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. Acid types, acid concentration as well as hydrothermal temperature and time were found to be effective route to manipulate the morphologies and composition of TiO₂-based nanoflakes grown on the NiTi fiber substrates. At the concentration of 0.4 mol L⁻¹ HCl as well as hydrothermal temperature of 150 °C and hydrothermal time of 12 h, TiO₂NPs were in situ grown on the NiTi wire substrates. The obtained NiTi wire with the TiO₂NPs coating (NiTi@TiO₂NPs fiber) was employed to investigate the adsorption of some representative aromatic analytes in water samples coupling with high-performance liquid chromatography with UV detection (HPLC/UV). The results clearly demonstrate that the fiber exhibits good extraction selectivity for ultraviolet filters (UVFs). In view of good extraction selectivity for the selected UVFs, the key experimental parameters were optimized. Under the optimum conditions, the calibration curves were linear in the ranges of 0.05–100 μg L⁻¹ with the correlation coefficients greater than 0.998. Limits of detection (LODs) were 0.007 to 0.064 μg L⁻¹. Furthermore, the intra-day and inter-day repeatability of the proposed method with the single fiber varied from 4.3% to 6.1% and from 4.5% to 6.8%, respectively. The fiber-to-fiber reproducibility ranged from 5.8% to 8.2%. The developed SPME-HPLC/UV method was applied to selective preconcentration and sensitive determination of target UVFs from real water samples. Moreover, the fabricated fiber showed precisely controllable growth and 150 extraction and desorption cycles.

This work presents a facile strategy with in situ growth of TiO₂ nanoparticles on nickel/titanium alloy wire through hydrothermal method for selective preconcentration and determination of UVFs in water.     

Electrochemical detection of 2-nitrophenol using a heterostructure ZnO/RuO2 nanoparticle modified glassy carbon electrode

A highly selective chemisensor for 2-nitrophenol detection was fabricated using ZnO/RuO₂ nanoparticles (NPs) synthesized by impregnation method. The as-synthesized NPs were characterized through UV-vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDS), FTIR and X-ray diffraction (XRD). A glassy carbon electrode was modified with as-synthesized ZnO/RuO₂ nanoparticles and utilized as a chemical sensor for the detection of 2-nitrophenol. The fabricated sensor exhibited excellent sensitivity (18.20 μA μM⁻¹ cm⁻²), good reproducibility, short response time (8.0 s.), the lowest detection limit (52.20 ± 2.60 pM) and long-term stability in aqueous phase without interference effects. Finally, the fabricated sensor was validated as a 2-NP probe in various environmental water samples at room conditions.

A highly selective chemisensor for 2-nitrophenol detection was fabricated using ZnO/RuO₂ nanoparticles (NPs) synthesized by impregnation method.     

Surface plasmon-driven photoelectrochemical water splitting of a Ag/TiO2 nanoplate photoanode

A silver/titanium dioxide nanoplate (Ag/TiO₂ NP) photoelectrode was designed and fabricated from vertically aligned TiO₂ nanoplates (NP) decorated with silver nanoparticles (NPs) through a simple hydrothermal synthesis and electrodeposition route. The electrodeposition times of Ag NPs on the TiO₂ NP were crucial for surface plasmon-driven photoelectrochemical (PEC) water splitting performance. The Ag/TiO₂ NP at the optimal deposition time of 5 min with a Ag element content of 0.53 wt% demonstrated a remarkably high photocurrent density of 0.35 mA cm⁻² at 1.23 V vs. RHE under AM 1.5G illumination, which was 5 fold higher than that of the pristine TiO₂ NP. It was clear that the enhanced light absorption properties and PEC performance for Ag/TiO₂ NP could be effectively adjusted by simply controlling the loading amounts of metallic Ag NPs (average size of 10–30 nm) at different electrodeposition times. The superior PEC performance of the Ag/TiO₂ NP photoanode was attributed to the synergistic effects of the plasmonic Ag NPs and the TiO₂ nanoplate. Interestingly, the plasmonic effect of Ag NPs not only increased the visible-light response (λ_max = 570 nm) of TiO₂ but also provided hot electrons to promote photocurrent generation and suppress charge recombination. Importantly, this study offers a potentially efficient strategy for the design and fabrication of a new type of TiO₂ hybrid nanostructure with a plasmonic enhancement for PEC water splitting.

A hybrid nanostructure Ag/TiO₂ photoelectrode for PEC water splitting with a remarkable high photocurrent density, 0.35 mA cm⁻² (5 fold higher than that of the pristine TiO₂ photoeletrode) was fabricated by a facile one-pot hydrothermal and electrodeposition method.     

Synthesis and characterization of nickel-doped ceria nanoparticles with improved surface reducibility

Nickel-doped ceria nanoparticles (Ni_0.1Ce_0.9O_2−x NPs) were fabricated from Schiff-base complexes and characterized by various microscopic and spectroscopic methods. Clear evidence is provided for incorporation of nickel ions in the ceria lattice in the form of Ni³⁺ species which is considered as the hole trapped state of Ni²⁺. The Ni_0.1Ce_0.9O_2−x NPs exhibit enhanced reducibility in H₂ as compared to conventional ceria-supported Ni particles, while in O₂ the dopant nickel cations are oxidized at higher valence than the supported ones.

Nickel-doped ceria nanoparticles (Ni_0.1Ce_0.9O_2−x NPs) were fabricated from Schiff-base complexes and characterized by various microscopic and spectroscopic methods.     

Rational design of a polypyrrole-based competent bifunctional magnetic nanocatalyst

The combination of conducting polymers with semiconductors for the fabrication of organic/inorganic hybrid nanocatalysts is one of the most promising research areas for many applications. In this work, the synthesized nanocomposite combines several advantages such as the photoresponse shift from the UV region toward visible light by narrowing the band gap of the semiconductor, magnetic separation ability and dual applications including the catalytic reduction of p-nitrophenol (PNP) and the photocatalytic degradation of methylene blue (MB) dye. In addition to the core magnetite nanoparticles (NPs), the synthesized nanocomposite contains polypyrrole (PPY) and TiO₂ shells that are decorated with silver metal NPs to prevent electron–hole recombination and to enhance the catalytic performance. Indeed, the catalytic PNP reduction experiments reveal that the synthesized nanocomposite exhibits significantly high catalytic activity with a rate constant of 0.1169 min⁻¹. Moreover, the photocatalytic experiments show that the synthesized nanophotocatalyst has a boosting effect toward MB dye degradation under normal daytime visible light irradiation with a rate constant of 6.38 × 10⁻² min⁻¹. The synergetic effect between silver NPs, PPY and TiO₂ is thought to play a fundamental role in enhancing the photocatalytic activity.

An efficient method to synthesize a magnetic nanocomposite with dual catalytic activities with a synergetic effect between Ag nanoparticles, polypyrrole and TiO₂ is described.     

The optical shielding performances and mechanisms of green flame-retardant two-component matte films under various application conditions

Herein, we meticulously investigated the optical shielding performances and mechanisms of green flame-retardant two-component waterborne polyurethane matte films based on a previous study. The relevant performances were evaluated by changing various environmental factors including nanoparticle content, pH, temperature and storage-time. Specifically, upon combination with TiO₂, the ultraviolet-light transmittance was reduced to 1.9% and the 60° glossiness decreased by 63%. When the pH was 8.0, the shielding efficiency and transmittance of ultraviolet light were 100% and 0%, respectively. The 60° glossiness of spin-films increased with an increase in storage time. Besides, TiO₂ nanoparticles were beneficial for delaying the thermal decomposition via synergistic flame retardance.

Herein, we meticulously investigated the optical shielding performances and mechanisms of green flame-retardant two-component waterborne polyurethane matte films based on a previous study.     

Enhanced visible-light photodegradation of fluoroquinolone-based antibiotics and E. coli growth inhibition using Ag–TiO2 nanoparticles

Antibiotics in wastewater represent a growing and worrying menace for environmental and human health fostering the spread of antimicrobial resistance. Titanium dioxide (TiO₂) is a well-studied and well-performing photocatalyst for wastewater treatment. However, it presents drawbacks linked with the high energy needed for its activation and the fast electron–hole pair recombination. In this work, TiO₂ nanoparticles were decorated with Ag nanoparticles by a facile photochemical reduction method to obtain an increased photocatalytic response under visible light. Although similar materials have been reported, we advanced this field by performing a study of the photocatalytic mechanism for Ag–TiO₂ nanoparticles (Ag–TiO₂ NPs) under visible light taking in consideration also the rutile phase of the TiO₂ nanoparticles. Moreover, we examined the Ag–TiO₂ NPs photocatalytic performance against two antibiotics from the same family. The obtained Ag–TiO₂ NPs were fully characterised. The results showed that Ag NPs (average size: 23.9 ± 18.3 nm) were homogeneously dispersed on the TiO₂ surface and the photo-response of the Ag–TiO₂ NPs was greatly enhanced in the visible light region when compared to TiO₂ P25. Hence, the obtained Ag–TiO₂ NPs showed excellent photocatalytic degradation efficiency towards the two fluoroquinolone-based antibiotics ciprofloxacin (92%) and norfloxacin (94%) after 240 min of visible light irradiation, demonstrating a possible application of these particles in wastewater treatment. In addition, it was also proved that, after five Ag–TiO₂ NPs re-utilisations in consecutive ciprofloxacin photodegradation reactions, only a photocatalytic efficiency drop of 8% was observed. Scavengers experiments demonstrated that the photocatalytic mechanism of ciprofloxacin degradation in the presence of Ag–TiO₂ NPs is mainly driven by holes and ˙OH radicals, and that the rutile phase in the system plays a crucial role. Finally, Ag–TiO₂ NPs showed also antibacterial activity towards Escherichia coli (E. coli) opening the avenue for a possible use of this material in hospital wastewater treatment.

Ag nanoparticles decorated-TiO₂ P25 are a viable alternative for the degradation, through a rutile-mediated mechanism, of fluoroquinolone-based antibiotics under visible light irradiation and, at the same time, for bacteria inactivation in water.     

In vitro cytotoxicity and antibiotic application of green route surface modified ferromagnetic TiO2 nanoparticles

The enormous numbers of applications of TiO₂ nanoparticles (NPs) cause concern about their risk to the environment and human health. Consequently, motivated by the necessity of searching for new sources of TiO₂ NPs of low cytotoxicity with antibacterial activity, we synthesized TiO₂ NPs by a green route using a solution of titanium(iv) isopropoxide as a precursor and an aqueous extract of Artocarpus heterophyllus leaf as a reducing and surface modifying agent. We investigated their structure, shape, size, and magnetic properties, and evaluated their antibiotic application and cytotoxicity. The synthesized TiO₂ NPs were applied against two Gram-negative bacteria (E. coli and S. typhimurium) and two Gram-positive bacteria (S. aureus and B. subtilis) to observe their antibacterial activity; and eventually clear zones of inhibition formed by the TiO₂ NPs were obtained. Moreover, after exposing the synthesized TiO₂ NPs to HeLa cells (carcinoma cells) and Vero cells (normal cells), no toxic effect was found up to a dose of 1000 mg L⁻¹, indicating the safe use of the samples up to at least 1000 mg L⁻¹. However, toxic effects on HeLa cells and Vero cells were observed at doses of 2000 mg L⁻¹ and 3000 mg L⁻¹, respectively. These results indicate the safe use of Artocarpus heterophyllus leaf extract mediated synthesized TiO₂ NPs in their potential applications.

Artocarpus heterophyllus leaf extract mediated green synthesized TiO₂ nanoparticles exhibit less toxicity with high antibacterial activity.     

N-doped TiO2 nanotube arrays with uniformly embedded CoxP nanoparticles for high-efficiency hydrogen evolution reaction

Efficient and stable non-precious metal based electrocatalysts are crucial to the hydrogen evolution reaction (HER) in renewable energy conversion. Herein, Co_xP nanoparticles (NPs) are uniformly embedded in N-doped TiO₂ nanotube arrays (Co_xP/N-TiO₂ NTAs) by low-temperature phosphorization of the precursor of metallic cobalt NPs embedded in N-doped TiO₂ NTAs (Co/N-TiO₂ NTAs) which were fabricated by phase separation of CoTiO₃ NTAs in ammonia. Owing to the abundant exposed surface active sites of Co_xP NPs, tight contact between the Co_xP NPs and TiO₂ NTAs, fast electron transfer in N-doped TiO₂, and channels for effective diffusion of ions and H₂ bubbles in the tubular structure, the Co_xP/N-TiO₂ NTAs have excellent electrocatalytic activity in HER exemplified by a low overpotential of 180 mV at 10 mA cm⁻² and small Tafel slope of 51 mV dec⁻¹ in 0.5 M H₂SO₄. The catalyst also shows long-term cycling stability and is a promising non-precious metal catalyst for HER.

Co_xP NPs embedded in N-doped TiO₂ NTAs was fabricated by phase separation of CoTiO₃ and delivers high efficient and stable HER performance in acid solution.     

Fabrication of plasmonic dye-sensitized solar cells using ion-implanted photoanodes

Plasmonic dye-sensitized solar cells containing metal nanoparticles suffer from stability issues due to their miscibility with liquid iodine-based electrolytes. To resolve the stability issue, herein, an ion implantation technique was explored to implant metal nanoparticles inside TiO₂, which protected these nanoparticles with a thin coverage of TiO₂ melt and maintained the localized surface plasmon resonance oscillations of the metal nanoparticles to efficiently enhance their light absorption and make them corrosion resistant. Herein, Au nanoparticles were implanted into the TiO₂ matrix up to the penetration depth of 22 nm, and their influence on the structural and optical properties of TiO₂ was studied. Moreover, plasmonic dye-sensitized solar cells were fabricated using N719 dye-loaded Au-implanted TiO₂ photoanodes, and their power conversion efficiency was found to be 44.7% higher than that of the unimplanted TiO₂-based dye-sensitized solar cells due to the enhanced light absorption of the dye molecules in the vicinity of the localized surface plasmon resonance of Au as well as the efficient electron charge transport at the TiO₂@Au@N719/electrolyte interface.

Ion implantation technique can resolve the stability issue of metal nanoparticles with liquid iodine-based electrolyte to improve PCE of plasmonic dye-sensitized solar cells.     

Rapid green-synthesis of TiO2 nanoparticles for therapeutic applications

Nanoparticles (NPs) with sizes ranging from 2 nm to 1 μm find various applications in the field of theranostics. Moreover, if eco-friendly methods are opted for the synthesis of biocompatible and less toxic NPs, then that''s a huge success. Titanium dioxide nanoparticles (TiO₂ NPs) have been vigorously studied for their use in medical implants, photodynamic therapy, drug delivery, biosensing and as antimicrobial agents. The present study reports the green-synthesis of TiO₂ NPs for the first-time using extracts of black pepper (Piper nigrum), coriander (Coriandrum sativum) and clove (Syzygium aromaticum). All three samples of TiO₂ NPs were synthesized via a modified sol–gel method under similar environmental conditions. Similar treatments were given to the samples. The procedure adopted for the synthesis ensures the use of non-toxic materials, no production of toxic by-products and rapid synthesis of the TiO₂ NPs. The NPs were characterized by X-ray diffraction, high resolution-transmission electron microscopy, energy dispersive spectroscopy, field emission scanning electron microscopy and selected area electron diffraction which confirmed the formation, morphology, crystallinity and size of the TiO₂ NPs. These characterizations displayed the similarity index of all three samples. However, photoluminescence and vibrating sample magnetometer studies highlighted the differences among the three samples. All three samples of NPs obtained had a size range of 5–20 nm. Further, the findings showed that different plant extracts result in TiO₂ NPs with moderately different characteristics. Furthermore, the samples were analysed for their drug-encapsulation efficiency using UV-visible spectrophotometry. Among all three samples, the NPs synthesised using black pepper exhibited the maximum encapsulation efficiency. The study concludes that the plant''s bio-profile is responsible for bringing about changes in the traits of the resulting nanoparticles. Thus, the extracts from different plants have the ability to manipulate the properties of the synthesized NPs. These findings can help to understand the role and importance of the plants in synthesizing NPs for biomedical applications. A further detailed study in this field can help researchers to understand the influence of the plant''s biochemistry in shaping the NPs.

Synthesis of TiO₂ nanoparticles using three different plant extracts results in different properties of the individual samples.     

Thermal,mechanical investigation and neutron shielding analysis for Gd-MOF/polyimide materials

None of the currently commercialized shielding materials in Generation IV nuclear energy systems are satisfactory in their performance. Developing a candidate neutron shielding material with good heat resistance and high strength is a challenging task. In this work, various gadolinium metal–organic frameworks (Gd-MOFs) with obvious advantages, such as porous structures, organic surfaces and strong neutron-absorbing nuclei, were synthesized to constrain polyimide (PI) chains. A series of Gd-MOF/PI conjugates were subsequently assessed for their thermal stability, mechanical properties and neutron shielding performance. The increase of the Gd-MOF content improved the thermal neutron shielding ability but slightly reduced the fast neutron shielding ability. Compared with those of pure PI, the Gd-MOF/PI films demonstrate a higher glass transition temperature (T_g), which is considered the gold standard of engineering plastics. It was also observed that the tensile strength directly correlates with the Gd-MOF content, which continuously increases until a maximum is reached, and then subsequently decreases. Furthermore, the high-temperature tensile test showed that these tunable Gd-MOF/PI films are intact and robust, indicating their potential application for neutron shielding materials in Generation IV nuclear energy systems.

None of the currently commercialized shielding materials in Generation IV nuclear energy systems are satisfactory in their performance.     

Ag@TiO2NPs/PU composite fabric with special wettability for separating various water–oil emulsions

In the present study, Ag@TiO₂ nanoparticles (NPs) were successfully synthesized by a hydrothermal method. Then the fabric (treated by dielectric barrier discharge (DBD) plasma and alkali desizing) was sprayed by solutions of polyurethane (PU) adhesive and as-prepared Ag@TiO₂NPs in sequence for constructing a robust multi-level structure. Afterwards, the durable superhydrophilic and underwater superoleophobic coatings were obtained on the fabric surface. With further octadecyl trichlorosilane (OTS) modification, the wetting behaviour of the coating was transferred to superhydrophobicity and superoleophilicity. Observations showed that both cotton fabrics exhibited excellent superwetting properties and antimicrobial activities even after experiencing repeated rinsing by water or oil, abrasion with the original cotton fabric or sand paper, and in chemical stability tests in a base and acid, etc. Moreover, the two types of Ag@TiO₂NPs/PU composite fabrics could successfully serve as filtering membranes for the fine reclamation of water or oil from their emulsion mixtures, which demonstrated high selectivity and efficiency, offering the theoretical foundation to extend the range of practical applications for textiles.

In present study, two types of Ag@TiO2NPs/PU composite fabrics with superwetting and antimicrobial properties were fabricated, which serve as the separating membrane for the fine reclaim of water or oil from their emulsion mixtures successfully.     

Effects of high magnetic field annealing on FePt nanoparticles with shape-anisotropy and element-distribution-anisotropy

The concave-cube FePt nanoparticles (NPs) with shape-anisotropy and element-distribution-anisotropy were annealed under a high magnetic field (HMF). The NPs underwent spheroidization and phase transformation during the annealing process. The HMF hardly affected the spheroidizing process of NPs, but obviously facilitated the disorder-order transition of the L1₀-phase. The L1₀-phase content, ordering degree, and the coercivity of annealed NPs increased with enhancing the HMF strength. Those results indicated that the nucleation of the L1₀-phase and ordering diffusion of Fe/Pt atoms were promoted by the HMF.

The concave-cube FePt nanoparticles (NPs) with shape-anisotropy and element-distribution-anisotropy were annealed under a high magnetic field (HMF).     

RGD-modified dihydrolipoamide dehydrogenase conjugated to titanium dioxide nanoparticles – switchable integrin-targeted photodynamic treatment of melanoma cells

The photocytotoxic effect of UVA-excited titanium dioxide (TiO₂), which is caused by the generation of reactive oxygen species (ROS), is often used in medical applications, such as cancer treatment. Photodynamic-therapy (PDT) is applied in several cancer models including cutaneous melanoma (CM), however the lack of selectivity causing damage to surrounding healthy tissues limits its applicability and novel targeted-delivery approaches are required. As cancer cells often overexpress integrin receptors (e.g. αvβ₃) on their cell surface, targeted delivery of TiO₂ nanoparticles (NPs) via an Arg-Gly-Asp (RGD) motif would make PDT more selective. We have recently reported that the mitochondrial enzyme dihydrolipoamide dehydrogenase (DLDH) strongly and specifically conjugates TiO₂via coordinative bonds. In this work we have modified DLDH with RGD moieties (DLDH^RGD), creating a molecular bridge between the integrin-expressing cancer cells and the photo-excitable TiO₂ nanoparticles. Physicochemical assays have indicated that the hybrid-conjugated nanobiocomplex, TiO₂–DLDH^RGD, is producing controlled-release ROS under UVA illumination, with anatase NPs being the most photoreactive TiO₂ form. This drug delivery system exhibited a cytotoxic effect in αvβ₃ integrin-expressing mice melanoma cells (B16F10), but not in normal cells lacking this integrin (HEK293). No cytotoxic effect was observed in the absence of UV illumination. Our results demonstrate the feasibility of combining the high efficiency of TiO₂-based PDT, with an integrin-mediated tumor-targeted drug delivery for nanomedicine.

This work presents a UVA switchable integrin-targeted photodynamic therapy in melanoma, composed of an RGD-modified DLDH conjugated to TiO₂ nanoparticles, with high selectivity towards integrin-expressing cancer cells.     

Photocatalytic properties of Cu-containing ZnO nanoparticles and their antifungal activity against agriculture-pathogenic fungus

In this work, nanoparticles (NPs) of ZnO, ZnO with Cu incorporated at 2 and 30 wt%, and CuO were prepared by the hydrothermal method. X-ray diffraction pattern (DRX) analysis showed that ZnO with high Cu incorporation (30 wt%) generates the formation of a composite oxide (ZnO/CuO), while X-ray photoelectron spectroscopy (XPS) of the Cu (2 wt%) sample indicated that Cu is incorporated as a dopant (ZnO/Cu_2%). The samples with Cu incorporated had enhanced visible light absorption. Methyl orange (MO) dye was used to perform photocatalytic tests under UV radiation. The antifungal activity of the NPs was tested against four agricultural phytopathogenic fungi: Neofusicoccum arbuti, Alternaria alternata, Fusarium solani, and Colletotrichum gloeosporioides. The ZnO/Cu_2% nanoparticles showed adequate photocatalytic and high antifungal activity in comparison to pure oxides and the composite sample.

In this work, nanoparticles (NPs) of ZnO, ZnO with Cu incorporated at 2 and 30 wt%, and CuO were prepared by the hydrothermal method.     

Novel TiO2/GO/CuFe2O4 nanocomposite: a magnetic,reusable and visible-light-driven photocatalyst for efficient photocatalytic removal of chlorinated pesticides from wastewater

A TiO₂/GO/CuFe₂O₄ heterostructure photocatalyst is fabricated by a simple and low-cost ball-milling pathway for enhancing the photocatalytic degradation of chlorinated pesticides under UV light irradiation. Based on the advantages of graphene oxide, TiO₂, and CuFe₂O₄, the nanocomposite exhibited visible light absorption, magnetic properties, and adsorption capacity. Integrated analyses using XRD, SEM, TEM, and UV-visible techniques demonstrated that the nanocomposite exhibited a well-defined crystalline phase, sizes of 10–15 nm, and evincing a visible light absorption feature with an optical bandgap energy of 2.4 eV. The photocatalytic degradations of 17 different chlorinated pesticides (persistent organic pollutants) were assayed using the prepared photocatalyst. The photocatalytic activity of the nanocomposite generated almost 96.5% photocatalytic removal efficiency of typical pesticide DDE from water under UV irradiation. The superior photocatalytic performance was exhibited by the TiO₂/GO/CuFeO₄ catalyst owing to its high adsorption performance and separation efficiency of photo-generated carriers. The photocatalyst was examined in 5 cycles for treating uncolored pesticides with purposeful separation using an external magnetic field.

A TiO₂/GO/CuFe₂O₄ heterostructure photocatalyst is fabricated by a simple and low cost ball milling pathway for enhancing the photocatalytic degradation of chlorinated pesticides under UV light irradiation.