Light Irradiation Research Articles

Photocatalytic therapy via photoinduced redox imbalance in biological system

Redox balance is essential for sustaining normal physiological metabolic activities of life. In this study, we present a photocatalytic system to perturb the balance of NADH/NAD+ in oxygen-free conditions, achieving photocatalytic therapy to cure anaerobic bacterial infected periodontitis. Under light irradiation, the catalyst TBSMSPy+ can bind bacterial DNA and initiate the generation of radical species through a multi-step electron transfer process. It catalyzes the conversion from NADH to NAD+ (the turnover frequency up to 60.7 min−1), inhibits ATP synthesis, disrupts the energy supply required for DNA replication, and successfully accomplishes photocatalytic sterilization in an oxygen-free environment. The catalyst participates in the redox reaction, interfering with the balance of NADH/NAD+ contents under irradiation, so we termed this action as photoinduced redox imbalance. Additionally, animal experiments in male rats also validate that the TBSMSPy+ could effectively catalyze the NADH oxidation, suppress metabolism and stimulate osteogenesis. Our research substantiates the concept of photoinduced redox imbalance and the application of photocatalytic therapy, further advocating the development of such catalyst based on photoinduced redox imbalance strategy for oxygen-free phototherapy.

Engineering the electron localization of metal sites on nanosheets assembled periodic macropores for CO2 photoreduction

Photocatalytic conversion of CO2 into syngas is highly appealing, yet still suffers from the undesirable product yield due to the sluggish carrier transfer and the uncontrollable affinity between catalytic sites and intermediates. Here we report the fabrication of Co sites with tunable electron localization capability on two dimensional (2D) nanosheets assembled three dimensional (3D) ordered macroporous framework (3DOM-NS). The as-prepared Co-based 3DOM-NS catalysts exhibit attractive photocatalytic performances toward CO2 reduction, among which the cobalt sulfide one (3DOM Co-SNS) shows the highest syngas generation rate up to 347.3 μmol h−1 under the irradiation of visible light and delivers a remarkable catalytic activity (1150.7 μmol h−1) in a flow reaction system under natural sunlight. Mechanism studies reveal that the high electron localization of metal sites in 3DOM Co-SNS strengthens the interaction between Co and HCOO* via the orbital interactions of dyz/dxz-p and s-s, thus facilitating the cleaving process of C-O bond. Additionally, the ordered macroporous framework with nanosheet subunits elevates the transfer efficiency of photoexcited electrons, which contributes to its high activity.

Impact of light spectrum electromagnetic radiation variations on performance and hormonal profiles in laying hens

Avian photopic curves show energy peaks at different wavelengths than humans, particularly in the ultraviolet, yellow, and red range. Therefore, an illumination system with a spectrum tailored for laying hens, encompassing the entire visible spectrum, can enhance performance and welfare. The primary contribution of this study was the development of two Spectral Power Distributions (SPDs) specifically designed for laying hens, with different spectral proportions (S1 and S2), and the evaluation of their effects on productive performance, egg quality, and hormonal levels, compared to conventional white lighting at 3000 K (C). The SPD with a higher emission of red light to increased egg production and egg mass. It also had a lower melatonin concentration, suggesting an inverse relationship with the egg production rate. Regarding egg quality, SPDs specifically designed for laying hens resulted in eggs with greater weight (S1), shell strength (S2), and yolk height (S1 and S2) and diameter (S2). The study’s results indicate that lighting emitting wavelengths within the spectrum visible to poultry, with higher emissions at long wavelengths, appears to be more favorable for laying hens than conventional lighting. A spectrum with higher emissions at shorter wavelengths appears to impair the productive performance of laying hens.

Dynamic Diselenide Hydrogels for Controlled Tumor Organoid Culture and Dendritic Cell Vaccination.

Dynamic hydrogels are emerging as advanced materials for engineering tissue-like environments that mimic cellular microenvironments. We introduce a diselenide-cross-linked hydrogel system with light-responsive properties, designed for precise control of tumor organoid growth and light-initiated radical inactivation, particularly for dendritic cell (DC) vaccines. Diselenide exchange enables stress relaxation and hydrogel remodeling, while recombination and quenching of seleno radicals (Se•) reduce cross-linking density, leading to controlled degradation. We demonstrate a 2D to 3D growth strategy, where tumor cells inoculate on the hydrogel surface, expand, and gradually form spherical organoids within the 3D hydrogel. These tumor organoids show significantly higher drug resistance compared to 2D-cultured cells. High-density light irradiation enhances diselenide exchange, inducing hydrogel degradation, tumor cell death, and release of functional antigens. This system serves as a dynamic platform for tumor organoid culture and antigen release, offering significantly advanced approaches for in vitro tumor modeling and immunological research. Our findings position diselenide-cross-linked hydrogels as versatile materials for precision cellular engineering, with broad applications in cancer research and beyond.

Advances in the Light-Promoted Transformations of N-Heterocyclic Carbene Ligated Boryl Radicals

AbstractOrganoboron compounds are integral to modern life, with extensive applications in synthesis, materials science, medicine, and various other domains closely linked to human endeavors. NHC-BH3, noted for its stability, ease of synthesis, and high reactivity as a boryl radical precursor, has emerged as a key focus in boryl radical chemistry. Recently, the visible-light-induced single electron transfer (SET) and hydrogen atom transfer (HAT) processes have garnered considerable interest, presenting innovative strategies for generating boryl radicals from NHC-BH3. In the context of this review, our focus is on the synthesis of C–B and X–B bonds under visible light irradiation, facilitated by NHC-BH3. Furthermore, we explored the role of NHC-BH3 as a hydrogen donor or halogen atom transfer reagent in the construction of C–C bonds.1 Introduction2 Hydroboration3 Borylation4 Construction of X–B Bonds (X = N, O, S)5 Halogen Atom Transfer Reagent and Hydrogen Donor6 Conclusion

Antibacterial and anti-biofilm activities of gold-curcumin nanohybrids and its polydopamine form upon photo-sonotherapy of Staphylococcus aureus infected implants: In vitro and animal model studies

Implant-related infections are among the major post-surgery problems, and treatment of these infections is challenging due to the formation of biofilms by microorganisms such as Staphylococcus aureus. Herein, a novel gold-curcumin nanohybrid (GCNH) was synthesized for the first time and characterized. GCNH had a band gap energy of 2.41 eV, a zeta potential of −15 mV, and comprised uniform spherical particles with a mean diameter of 8 ± 2 nm. The biological macromolecule of polydopamine was then coated on GCNH to prepare a gold-curcumin-polydopamine nanohybrid (GCDNH). The nanohybrids were employed as novel dual photo-sonosensitizers for bacterial eradication by near-infrared (NIR) light and ultrasound (US) irradiations. GCNH and GCDNH represented photothermal conversion efficiencies of 26 and 32 %, respectively, and GCDNH represented a hemolysis rate of 2.3 % under both near-infrared (NIR) light and ultrasound (US) irradiations. NIR light and US irradiations (photo-sonotherapy) of Staphylococcus aureus using GCDNH depicted anti-bacterial and anti-biofilm efficiencies of 98 and 99 %, respectively, in synergistic manners, which are higher or as high as other sensitizers reported previously. The mechanism of photo-sonotherapy was related to generation of high levels of reactive oxygen species (ROS), and protein and nucleic acid leakages. In an in vivo infection model, NIR light and US irradiations annihilated Staphylococcus aureus on GCDNH-covered implants with high efficiency, without causing damage to normal tissues.

Flexible and lightweight metalized polyamide nonwoven for electromagnetic interference shielding, electrothermal, photothermal, and antibacterial applications

The adoption of multifunctional nonwovens (NWs), which have more than one primary use, is increasing worldwide. In this paper, metalized nylon 6 NWs are prepared using nickel–phosphor (Ni-P) plating for electromagnetic shielding, electrothermal, photothermal, and antibacterial applications. The sensitized and activated NWs are deposited in an electroless nickel plating for different durations. The deposition amount increased in the electroless plating process from 1 to 8 min. Afterward, the precipitation rate of Ni-P particles decreases, and the coated surface of the NWs also becomes non-uniform. Surface morphology and elemental analysis mapping showed that Ni-P particles are uniformly deposited on surfaces of Ni-P/NWs with 8 min electroless plating. As a result, it is shown that the sample with 8 min electroless plating is the optimal and best sample to use in the shielding effectiveness of 55.4 dB, and specific shielding of 490.27 dB.cm3.g−1. Also, the optimal specimen has the best electrothermal application with an average maximum temperature of 133.5 °C at 5 V with relative preservation of the necessary properties of the fabric, compared to other prepared samples. Also, this optimal fabric in the photothermal performance, reaches an average maximum temperature of 77.9 °C in 800 mW/cm2. The optimal sample shows significant antibacterial efficiency against E. coli and S. aureus bacteria and reaches 62.70 ± 0.20 and 88.30 ± 1.30 % under light irradiation, respectively. The results show that the optimal sample with great washing durability can perform very well in cold environments and exhibit excellent shielding, electrothermal, and photothermal performances which can be used as lightweight electro-heating and shielding fabrics.

Surface self-modification of TiO2 for enhanced photocatalytic toluene oxidation via photothermal effect

Surface modification plays an important role in extending light absorption and enhancing the catalytic performance of semiconductor photocatalysts. However, most current studies focus on pre-modification of the semiconductors before reaction, while surface self-modification of catalyst during photocatalytic reaction process is often neglected. Here, we report the surface self-modification of TiO2 catalyst during photocatalytic oxidation of toluene under UV light irradiation, which changes the colour of TiO2 from white to yellow, and effectively extends its light absorption range into visible light region. The absorbed visible light is primarily released as thermal energy, significantly increasing the temperature of the catalytic system. Mechanistic studies reveal that the temperature elevation facilitates the separation of photogenerated charge carriers in TiO2 and promotes the generation of •O2−, consequently accelerating the surface redox reactions. The surface self-modified TiO2 exhibits an enhanced photothermal catalytic benzaldehyde generation of 4485 μmol g−1h−1 under UV–visible light irradiation, which surpasses the UV-driven activity of TiO2 by a factor of 1.9. This study offers new perspectives on the surface modification of semiconductor photocatalysts during organic transformations. It is anticipated to trigger increased research attention to this effect, ultimately advancing solar-to-chemical energy conversion.

Multilayered heterojunction-based zinc oxide nanoneedles/polyaniline/titania nanoparticles as a self-powered ultraviolet light photodetector

Nowadays, self-powered ultraviolet photodetectors (SPDs) with improved photoresponse features have attracted considerable attention due to their great pivotal applications in military and civilian fields. In the present work, for the first time, we investigate and report the construction and photoresponse features of a SPD based on multilayered heterojunction-based zinc oxide nanoneedles/polyaniline/titania nanoparticles (ZET). The structure, morphology, and optical properties of the ZET and its components were comprehensively investigated. A significant dependence was observed between the changes in I-V characteristics of the ZET-based SPD (SPZ) and the temperature change, resulting in a short reverse saturation current, proper ideality factor, and low dark current. I-V characteristics of the SPZ revealed nonlinear asymmetric rectifying behavior with the improved current under the influence and increase of power densities (PDiss) of ultraviolet (UV) light irradiation. Moreover, the self-powered feature of the SPZ was confirmed by the generation of short-circuit current and notable contrast ratio under UV light illumination at zero bias voltage. The device displayed remarkable photoresponsivity of 4.46A/W, high significant normalized detectivity of 63.1×1012Jones, good fill factor of 50.64%, and excellent external quantum efficiency of 1514% at the PDis of 0.77mW/cm2. In addition, the SPZ exposed a short rise time of 540 ms, a high maximum photocurrent of 99.9µA, and a significant gain dynamic range of 499.5 at PDis of 19.11mW/cm2. Finally, the imaginable mechanism of the current generation in our hand-made device was discussed in detail by exerting a standard thermionic emission-diffusion model and energy band diagram.

Covalent triazine frameworks as particle electrode for three-dimensional photoelectrocatalytic degradation of oxytetracycline: Synergy effects, pathway, and mechanism.

Photoelectrocatalysis has been widely employed for degrading antibiotics due to its high efficiency. However, the application is significantly impeded by the rapid recombination of photogenerated charge carriers and the limited surface areas of photoelectrodes. In the study, high crystallinity covalent triazine frameworks were fabricated at low temperature of 150°C and firstly used as particle photoelectrode in the three-dimensional photoelectrochemical reactor to degrade oxytetracycline (OTC). SEM, TEM, XRD, XPS, and FT-IR confirmed the successful synthesis of high crystallinity covalent triazine frameworks. Compared to CTF-120 (71.2%) and CTF-180 (46.9%), CTF-150 exhibited excellent OTC removal. Electrochemical impedance, UV-vis absorption spectra, and Mott-Schottky tests showed that CTF-150 demonstrated more wide light absorption range of 501nm and narrow bandgap of 2.52eV, and smaller Rct value under illumination, in comparing to CTF-120 and CTF-180. When the initial concentration of OTC was 50mgL-1, the 86.2% of OTC removal and 62.7% of mineralization were obtained under light irradiation (λ>420nm), current of 10mA, pH of 6.4, electrolyte of 0.1M Na2SO4. The synergy effect between photocatalytic and electrocatalytic processes of CTF-150 not only enhanced by 38.5% current efficiency but also reduced energy consumption to 1.90 kWh m-3. CTF-150 had a wide range of acid-base application and displayed resistance on coexisting ions. Electron spin resonance detection, quenching experiments, and probe experiments illustrated that h+, •O2-, 1O2, and •OH contributed to the degradation of OTC and the generation pathways of •O2-, 1O2, and •OH were verified. Moreover, •O2-, 1O2, and h+ were the main reactive species responsible for OTC removal, while 1O2 was for OTC mineralization. Based on high-performance liquid chromatography-tandem mass spectrometry detection, OTC with benzene ring was decomposed to opening ring products. The acute toxicity, developmental toxicity, bioaccumulation factor and mutagenicity of OTC and its intermediates using T.E.S.T. showed the toxicity of 82.35% degradation products decreased.

Construction of nucleus-targeted photosensitizer and highly effective photodynamic immunotherapy for cancer

Nucleus is the largest and most important organelle within eukaryotic cells, containing most of the cell’s genetic material, DNA. It serves as the central hub for genetic regulation and metabolism, making it an ideal target for subcellular drug delivery. The development of nucleus-targeted photosensitizers allows for the rapid and effective destruction of critical components such as DNA within the nucleus. This achieves the goal of efficiently eliminating cancer cells. However, most organic molecules, including photosensitizers, cannot penetrate the nuclear membrane, making the design and synthesis of nucleus-targeted photosensitizers both significant and challenging. The authors have designed and synthesized a nucleus-targeted activatable photosensitive probe (CMT-I). In vitro spectral analyses demonstrate that CMT-I is specifically activated by ct-DNA, significantly enhancing fluorescence-a 49-fold increase is observed upon binding. Furthermore, under 590 nm light irradiation, CMT-I effectively generates 1O2. Molecular docking show that CMT-I selectively binds to DNA through hydrogen bonds and ᴨ-ᴨ conjugation. RNA sequencing experiments reveal that photodynamic therapy activates immunity within tumor cells, triggering an adaptive immune response. In vivo therapeutic experiments further verify the enhanced anti-tumor immunity of CMT-I, which is crucial for effectively eliminating immunologically cold tumors and highlights the potential of DNA-targeted photodynamic therapy in precise cancer treatment.

Wavelength-Dependent Dynamic Behavior in Thiol-Ene Networks Based on Disulfide Exchange.

While latent catalysts have become a well-established strategy for locally and temporally controlling bond exchange reactions in dynamic polymer networks, there is a lack of inherently tailorable systems. Herein, we introduce a thiol-ene network based on disulfide exchange that alters its dynamic properties as a function of the color of light used during the curing reaction. For this purpose, selected allyl-bearing disulfides are synthesized, which are transparent at 450 nm but undergo disulfide scission upon 365 nm light irradiation, as confirmed by UV-vis and EPR measurements. Incorporated into a thiol-ene resin, the wavelength used in the curing reaction defines the dynamic properties of the obtained photopolymer. At 450 nm, photocuring yields a dynamic network with disulfide bonds, which relaxes to 63% of its original stress within 112 s at 160 °C (without the requirement of an external catalyst). In contrast, curing with 365 nm light induces disulfide scission yielding photopolymers, which contain predominately monosulfidic links. The permanent nature of the links effectively prevents relaxation of the polymer within a reasonable period of time, confirming the successful alteration of its dynamic properties simply by the color of the light source used.

Salt-induced anisotropic SrTiO3 to boost piezo-photocatalytic processes

Piezo-photocatalysis materials that can combine the piezoelectric effect in photocatalytic processes are very attractive for promising applications in water splitting and contaminant degradation. The perovskite oxides with adjustable exposed crystal facets are expected to optimize the catalysis activities by exposing the high-energy planes. In this work, we develop a salt-assisted strategy that controllably prepares anisotropic SrTiO3 particles with a large number of surface defects, which exhibit good piezo-photocatalytic features. The exposure of the crystal facets can be tuned by changing the assistants (NaCl or SrCl2). The SrCl2 can lead to the exposure of the (110) plane in one-dimensional SrTiO3 particles and NaCl can induce the cubic SrTiO3 particles with the exposure plane of (200). Attributed to the exposed high-energy facets and abundant oxygen vacancies, the latter show higher activities than the former in both water splitting and dye degradation under light irradiation and ultrasonic vibration. Our work provides an approach to optimize piezo-photocatalytic activities by tuning the exposed crystal facets.

Metallo‐supramolecular nanofibers based on type‐I photosensitizer for synergistic antibacterial therapy

AbstractPhotodynamic therapy (PDT) has shown great merits in treating microbial infections due to its absence of bacterial resistance. However, the pronounced hypoxic microenvironment in the bacterial infections limits the therapeutic efficiency of traditional type‐II PDT, which is highly dependent on oxygen. Here type‐I photosensitizer BTZn‐Py (n = 8, 20) coordinates with chemical antibacterial agent Ag+ to fabricate metallo‐supramolecular nanofibers. Under light irradiation, the formed nanofibers could not only generate type‐II reactive oxygen species (ROS), 1O2, but also produce type‐I ROS O2•− which addressed the hypoxic issues within infected tissues. Moreover, the acid‐ and photo‐active Ag+ release from the nanofibers endowed the metallo‐supramolecular nanofibers with controlled release characteristic, which showed good biocompatibility to normal tissues. Owing to controlled Ag+ release and photoinduced type‐I ROS, the in vitro and in vivo experiments confirmed the significantly synergistic antibacterial performance of the metallo‐supramolecular fibers against both Gram‐positive and Gram‐negative bacteria.

Covalent organic framework-assisted solar energy storage in long-lived organic radicals for enzyme-free colorimetric detection of xanthine

Xanthine monitoring is meaningful for both human health and food industrial, but rapid, cost-saving and natural enzyme-free detection of xanthine is still a big challenge. Herein, a new covalent organic framework (FPPy-TSC COF) with unique photoelectric properties is developed for rapid, enzyme-free and sensitive colorimetric detection of xanthine in complex real samples. In the presence of xanthine, FPPy-TSC COF interacts with xanthine through hydrogen bonds, and the electrons generated by FPPy-TSC COF under light irradiation can be transferred to xanthine with the result of storing solar energy in the form of long-lived organic radicals. Then the electrons stored in xanthine gradually reduce dissolved oxygen to oxygen radicals under dark conditions, which subsequently catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxidized products (oxTMB). Based on the characteristic absorption and color changes, xanthine can be detected under dark condition by naked eyes, spectrometry and smartphone with the detection limit low to 3.23μM (3σ/K). Moreover, xanthine contents in serum and pork samples can be accurately detected with the recoveries ranging from 95.28 to 107.34%. This work not only proposes a novel enzyme-free detection system for xanthine, but also broadens the sensing application of COF nanozymes under dark condition.

Colorimetric and fluorimtric microenvironment responsivity of oxazolidine in solvatochromic latex nanoparticles: Versatile intelligent polymeric materials with advanced applications

Oxazolidine, a new category of stimuli-chromic dyes, has displayed a wide range of responsivities, such as halochromism, solvatochromism, ionochromism, and hydrochromism. The optical properties of oxazolidine molecules can be influenced notably by the polarity of solvent, media, and polymer nanoparticles. In this study, multi-functionalized acrylic latex nanoparticles containing different polar functional groups such as amide, amine, acid, hydroxyl, epoxide, and long-chain ester were synthesized by one-pot emulsion copolymerization. Prepared latex nanoparticles have a mean particle size in the range of 45–170 nm and spherical or non-spherical (anisotropic) morphologies depending on the polarity of functional groups. To prepare multi-color photoluminescent latex nanoparticles and investigation of solvatochromism in both colloidal solution and solid phase, as prepared multi-functionalized latex nanoparticles were modified physically with an oxazolidine derivative (5 wt%). Investigation of the solvatochromism of the oxazolidine in colloidal solution and solid phase indicated that the media is the main effective parameter for solvatochromism in colloidal solution. In the case of solid-state solvatochromism, the optical properties of oxazolidine were influenced significantly by the polarity of functional groups, because the interactions of oxazolidine molecules with functional groups of latex nanoparticles is the main parameter that influenced the solvatochromism. The solvatochromic properties of oxazolidine in solid polymer powders are useful for developing multi-color photoluminescent materials with advanced applications in the dual-mode visualization of latent fingerprints (LFPs), anticounterfeiting solid inks, and organic light-emitting diodes (OLEDs). Results displayed potential applications of multi-color polymer powders for the detection of LFPs under visible light and UV-light irradiation, for printing of optical security tags, and construction of OLEDs. The presented study introduces a new category of multi-color solid photoluminescent nanomaterials with multiple applications using solvatochromic properties.

Enhanced Photocatalytic Degradation of Ciprofloxacin Antibiotics using Fe3O4-SiO2-EN@Zn-Al Layered Double Hydroxide Nanocomposites under the COVID-19 pandemic

A novel layered double hydroxide nanocomposite, Fe3O4-SiO2-EN@Zn-Al-LDH, was synthesized and employed as a photocatalyst for the degradation of ciprofloxacin (CIP) in aqueous solutions. Characterization of the photocatalyst was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) techniques. The results indicated successful synthesis of particle with specific surface area of 28.67 m²/g, pore size of 1.64 nm, and pore volume of 6.58 cm³/g. Optimal degradation of CIP was observed under the following conditions: pH 5, photocatalyst dosage of 0.6 g/L, initial CIP concentration of 25 mg/L, and an irradiation duration of 60 minutes. Comparative experiments demonstrated that incorporating Zn-Al LDH with core-shell nanoparticles (Fe3O4-SiO2-EN) enhanced removal efficiency by 2.5 to 6 times compared to individual materials. The composite exhibited efficient activation under UV, visible light, and solar radiation, resulting in 100% degradation of CIP under UV, 100% under visible light, and 81.4% under solar radiation. Biodegradability, indicated by the BOD5/COD ratio, increased from 0.28 to 0.73 after 120 minutes of photocatalytic oxidation under visible light, with 80.83% COD removal and 74.17% TOC removal. Reactive species generation, such as •OH, •O2-, and h+, was confirmed by introducing scavengers (TBA, BQ, and TEOS) into the reaction medium. The photocatalytic activity of the nanocomposite was slightly decreased over 5 consecutive CIP treatment cycles. Toxicity assessment of treated wastewater using E. coli and Daphnia magna bioassays revealed a significant decrease in E. coli growth inhibition rate with prolonged treatment time. The EC50 percentage improved from 1.27% to 97.4% after 4 hours of CIP treatment under visible light. In conclusion, the development of the Fe3O4-SiO2-EN@Zn-Al-LDH presents a noteworthy advancement in photocatalysis for the degradation of CIP in aqueous solutions.

Synthesis of silver-decorated titanium dioxide nanostructured films for enhanced visible light photocatalysis

Titanium dioxide (TiO2) has been extensively investigated for applications in photocatalysis due to its stability, nontoxicity, and robust photocatalytic properties. Although thin films of TiO2 are effective in wastewater treatment, their dense structure limits surface accessibility. The oblique angle deposition (OAD) technique can be used to create high surface area nanostructured thin films essential for photocatalytic applications. In this study, OAD was used to grow TiO2 thin films. To extend the activity to the visible light region, plasma-reduced silver (Ag) particles were coupled to the TiO2 surface. The Ag-decorated TiO2 (Ag-TiO2) nanostructured films were fabricated using a custom-built magnetron sputter deposition system with OAD technique capability. Different substrate angles of 0°, 35°, and 70° with respect to the target normal were used. The films were characterized for their structural, compositional, and optical properties. The photodegradation performance was evaluated using methylene blue (MB) as the test analyte under visible light irradiation. The results showed a significant improvement in degradation efficiency using plasma-reduced Ag-TiO2. Substrates tilted at 70° achieved the highest MB degradation efficiency of 89.84% after 5 h exposure. This tilt angle also revealed high surface roughness and high surface area. By tilting the substrate with respect to the target, high surface area thin films can be fabricated. This technique is ideal for applications that depend on the area of contact, such as photocatalysis.

0-Dimentionnal/1-dimentional S-scheme Ag2S/BiSI hetero-structured photocatalyst for superb Cr(VI) reduction under full spectrum irradiation

Developing ultraviolet (UV), visible (Vis) and near-infrared (NIR) responsive photocatalysts for Cr(VI) reduction is valuable. Herein, a 0-dimentionnal/1-dimentional (0D/1D) S-scheme Ag2S/BiSI hetero-structured photocatalyst was successfully synthesized, which displays greatly enhanced Cr(VI) removal activity either under UV, Vis or NIR light irradiation. In-situ characterization technique and theoretical calculation confirm that an internal electric field (IEF), directing from Ag2S to BiSI, exists between the interface, which facilitates the spatial-oriented separation of photoirradiated carriers. Furthermore, the immobilization of Cr2O72− and the transformation from *Cr2O72− to *CrO3H2 on the surface of S-scheme Ag2S/BiSI heterostructure is much more favorable than that on the surface of single Ag2S or BiSI. This work gives a comprehensive insight on the design of full spectrum responsive S-scheme photocatalysts for heavy metal removal.

Tecoma stans intermediated green synthesis of copper oxide nanoparticles, its characterization, paracetamol degradation and biological activities

The main objective of the present research work is to green synthesize copper oxide nanoparticles (CuO NPs) and to study its potential against various enmities to safeguard our environment and health. Based on this approach, preparation of CuO NPs was accomplished using four different volumes (10, 25, 40, and 50 mL of leaves extract) of Tecoma stansleaves extract. Moreover, all the synthesized CuO NPs were characterized using XRD, UV–visible, FTIR, and SEM with EDS analysis. From the XRD pattern, the structures of all the synthesized CuO NPs were found to be monoclinic in phase. According to the UV–visible studies, the calculated band gap energy values for all the prepared CuO NPs were higher compared to bulk CuO, which was 1.2 eV. Further, the FTIR results showed the presence of CuO bond and SEM with EDS analysis revealed the surface morphology of CuO NPs andthe presence of elements showing the purity of synthesized CuO NPs, respectively. The optimized condition for the preparation of CuO NPs were 50 mL of leaves extract mixed with 50 mL of double distilled water (CuO4 NPs) showed a spheroidal morphology as evident from the HRTEM images. XPS analysis used to find the oxidation state of detected elements especially for copper and oxygen. The predicted BET and Langmuir surface area of CuO4 NPs were calculated to be 40.305 m2/g and 5074.12 m2/g respectively. Photocatalytic degradation of paracetamol (PCM) using CuO4 NPs was investigated, and the effect of parameters such as pH, initial concentration of PCM solution, and catalyst dosage were studied under UV light irradiation. The highest removal of 95.15 % had been achieved at 120 min under optimized reaction conditions. Additionally, CuO4 NPs also exhibited exemplary antibacterial activity against bacillus subtilis bacteria with a zone of inhibition of 26 mm. Further, in vitro cytotoxic behaviour of CuO4 NPs was estimated using A549 cancer cells by MTT assay. Thus, the green synthesis of CuO NPs using Tecoma stans leaves extract has the capacity to participate in photocatalytic and biological activities.