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The kesterite Cu 2 ZnSnS 4 (CZTS) thin-film solar cell is one of the emerging solar cells. The Zn and Sn materials were prepared to substitute the rare In and Ga materials in previous CuInGaS 2 cell generation. However, the secondary phase formation and the non-uniform film formation during the solution process affect deteriorating cell performance. By considering the CZTS kesterite structure, secondary phases, bandgap, and absorbance, this work aims to present the novel achievement of solution processed-pure Cu 2 ZnSnS 4 /CdS solar cell. The solar cell was made with the structure of Mo/Cu 2 ZnSnS 4 /CdS/ITO/Ag consisting of 21 subcells. The characterizations were employed through X-ray diffraction (XRD), external quantum efficiency, energy gap, and J-V curve. To the best knowledge, without further cation exchange modification and the atomic ratio of Zn/Sn = 1.26 and Cu/(Zn + Sn) = 0.86, the fabricated solar cell exhibits the novel achievement for the pure Cu 2 ZnSnS 4 /CdS standard solution process with the power conversion efficiency of 7.5% with 1.43 eV bandgap and 83.5% external quantum efficiency at 570 nm. The correlation between kesterite, secondary phases, bandgap, absorbance, dan cell performance statistics were further discussed. This work implied considering the atomic ratio of Cu-poor, Zn-rich, and the film uniformity during the spin coating process; it plays a significant role in achieving high-performance solution-processed CZTS solar cells. • CZTS thin film was prepared through the solution process. • Pure CZTS/CdS solar cell has achieved a novel record of 7.5% efficiency. • Optical parameters: absorbance, bandgap, cristal structure were further discussed. [ABSTRACT FROM AUTHOR]

• Recent progress in porous organic polymers (POPs) for metal ion removal is summarized. • Strategies to prepare heterotopic atoms-inserted POPs with enhanced adsorption performance are detailed. • The current challenges and future prospects of POPs for metal ion removal are discussed. Owing to their high porosity, flexible structure and excellent chemical stability, porous organic polymers (POPs) have drawn significant interests especially in wastewater remediation. In this review, the recent research progress in adsorptive removal of toxic metal ions from aqueous solutions through the use of POPs is summarized. A selective collection of studies illustrating the reliable strategies and concepts to prepare heterotopic atoms-inserted POPs with enhanced affinity and selectivity toward various metal ions is discussed in detail and the key features of POPs as adsorbents in terms of accessible binding sites in the scaffold are highlighted. Finally, the current challenges and future prospects to establish structure–property–function relationships are provided to accelerate the rational design and synthesis of high-performance POPs for practical adsorption applications. [ABSTRACT FROM AUTHOR]

The acid dissociation constant (p K a) is the fundamental physicochemical properties required to understand the structure and reactivity of boronic acid-based material as a sensor that identifies carbohydrates. However, there is a lack of comprehensive study on the impact of the substituent on the p K a of monosubstituted phenylboronic acid in aqueous and non-aqueous solutions. In this work, extensive experimental data on the p K a of monosubstituted phenylboronic acid in an aqueous solution was reviewed and compared in terms of accuracy. In addition, computational, were used to predict and investigate the impact of the substituent on the p K a for a series of monosubstituted phenylboronic acid in an aqueous solution at the molecular level. Good agreement was observed between predicted and literature p K a values of monosubstituted phenylboronic acid in the aqueous solution. While some deviations exist, predominantly with fluorine-containing phenylboronic acid, the COSMO-RS model is proficient at predicting the p K a of boronic acid in an aqueous solution with the accuracy of ±1.5 pKa. Subsequently, the model was used to predict the p K a of boronic acid in the non-aqueous solution, which data is not available in the literature. Furthermore, an excellent relationship is observed between the acidity of para -substituted, and to some extent, meta -substituted phenylboronic acid with the atomic charge of acidic hydrogen calculated using Natural Bond Orbital (NBO) Population Analysis. In contrast, the steric hindrance and the existence of other molecular forces might influence the acidity of ortho -substituted phenylboronic acid. The gathered information in this work could be of benefit for the understanding of the acidity of the boronic acid-based materials not only as a sensor but also in many diverse areas. • COSMO-RS can be used to predict p K a of phenylboronic acid in aqueous solution. • Acidity of phenylboronic acid is related to the atomic charge of acidic hydrogen. • The p K a of phenylboronic acid in organic solvents is predicted for the first time. [ABSTRACT FROM AUTHOR]

• Self-templated fabrication of hollow Mn-Co phosphide yolk-shell is reported. • Difference in inward and outer diffusion leads to hollow yolk-shell structure. • Mn-Co phosphide catalyst shows higher activity for OER than its oxide counterpart. • Mn3+ and Co3+ active sites give rise to high activity for OER. Hierarchical nanostructures with hollow architectures can provide rich active sites, improved transport of ions, and highly robust structure for electrochemical applications. In this work, we report the self-templated fabrication of hierarchical manganese-cobalt phosphide (Mn-Co phosphide) yolk-shell spheres using highly uniform cobalt glycerate spheres as sacrificial templates. Through a simple exchange reaction with the manganese precursor solution at room temperature, these cobalt glycerate spheres are readily converted to hierarchical Mn-Co LDH yolk-shell spheres, which can be further phosphidized at 350 °C under inert atmosphere to generate hierarchical Mn-Co phosphide with distinct yolk-shell morphology. When tested as an electrocatalyst for oxygen evolution reaction (OER), the hierarchical Mn-Co phosphide yolk-shell spheres exhibit an overpotential of 330 mV at a current density of 10 mA cm−2 and a Tafel slope of 59.0 mV dec-1, which are higher than those of Mn-Co oxide yolk-shell spheres (480 mV and 113 mV dec-1) and hierarchical cobalt phosphide spheres (410 mV and 61.3 mV dec-1). Post-OER analysis by XPS reveals that the high activity of the hierarchical Mn-Co phosphide yolk-shell catalyst originates from the existence of Mn4+/Mn3+ and Co2+/Co3+ redox couples and the formation of active metal oxyhydroxide species on its surface. The proposed self-sacrificial templating strategy will provide useful guidance for future construction of hollow inorganic metal nanostructures with yolk-shell morphology for energy storage and conversion applications. [ABSTRACT FROM AUTHOR]

Titanate nanotubes (TiNT) were deposited over the surface of 100 pores per inch (ppi) reticulated vitreous carbon (RVC) by anodic electrophoresis at a cell voltage of 15 V, in an undivided cell, from an ethanol/water suspension containing TiNT coated with tetrabutylammonium hydroxide (TBAOH) surfactant. Scanning electron microscopy showed the open cell porous structure of TiNT/RVC coated by a uniform ca. 30 μm thick layer of TiNT. Calcination at 450 °C for 2 h in air improved the photocatalytic properties. The material was used as photocatalyst for the decolourisation of methylene blue (MB) dye. The 98% volumetric porosity of the RVC substrate provided good reactant access and large surface area for deposition of TiNT. The calcined TiNT/RVC substrate achieved a 91% dye degradation after 20 min, which was higher than uncoated, acid treated RVC and non-calcined TiNT/RVC substrate. The MB decolourisation improved at an increased thickness of 3D TiNT/RVC catalyst although the improvement was limited to 4 mm on 100 ppi RVC due to limited UV penetration. Unlabelled Image • Anodic electrophoresis produced a stable TiNT film on 100 ppi RVC. • SEM imaging showed uniform deposition of TiNT. • The acid treatment of RVC increased the ratio of I D / I G as seen in Raman spectra. • Decorated RVC was used as a photocatalyst for decolourisation of MB dye. [ABSTRACT FROM AUTHOR]

Nanofibers have been demonstrated to be highly effective for drug delivery applications. Although magnetic nanoparticles (MNPs) have been potentially added to nanofibers for improved drug release stimulation, the effect has been limited. In this study, a magnetic nanofiber membrane composed of cellulose acetate (CA), collagen (COL), and MnFe 2 O 4 MNPs was prepared by electrospinning. Naproxen (NAP) drug was deposited on the nanofibers, and the drug release mechanism and effect of the MNPs on the stimulated NAP release were investigated. The electrical conductivity of the dope solution strongly affected the nanofiber characteristics. Moreover, the MTT cytotoxicity assay proved that CA-COL, CA-COL-NAP, and CA-COL-NAP-MNP nanofibers had low toxicity, as the cell viability was >80%. The NAP release mechanism was determined using zero-order, first-order, Higuchi, and Korsmeyer-Peppas kinetics models. According to the dissolution results, for all nanofibers, the NAP release followed the Korsmeyer-Peppas kinetics model, and the transport mechanism was Fickian diffusion. A high MNP concentration and neutral pH condition were conducive to NAP release. Image 1 • Designing composite nanofiber from cellulose acetate, collagen, MnFe 2 O 4 MNPs along with naproxen as drug loaded. • Higher amount on MNPs give positive impact on make smaller nanofiber. • Explore kinetical release of naproxen from nanofiber that accelerated by magnetic induction. • The release mechanism of naproxen close to Korsmeyer-Peppas kinetics models with Fickian diffusion. [ABSTRACT FROM AUTHOR]

In article number 1400470, Brian Yuliarto, Jeung Ku Kang, and co‐workers describe efficient light‐harvesting antenna made up of plasmonic silver nanoparticles coordinated with natural extracts of graminomids for bio‐photovoltaic cells. It is found that the photon quenching is critical for collecting electrons from the natural extracts, thus providing a new strategy to enhance the efficiency of bio‐photo‐voltaic cells. [ABSTRACT FROM AUTHOR]

TiO 2 remains one of the most popular materials used in catalysts, photovoltaics, coatings, and electronics due to its abundance, chemical stability, and excellent catalytic properties. The tailoring of the TiO 2 structure into two-dimensional nanosheets prompted the successful isolation of graphene and MXenes. In this review, facet-controlled TiO 2 and monolayer titanate are outlined, covering their synthesis route and formation mechanism. The reactive facet of TiO 2 is usually controlled by a capping agent. In contrast, the monolayer titanate is achieved by ion-exchange and delamination of layered titanates. Each route leads to 2D structures with unique physical and chemical properties, which expands its utilisation into several niche applications. We elaborate the detailed outlook for the future use and research studies of facet-controlled TiO 2 and monolayer titanates. Advantages and disadvantages of both structures are provided, along with suggested applications for each type of 2D TiO 2 nanosheets., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

α-Phase formamidinium lead iodide (FAPbI 3 ) perovskite solar cells (PSCs) have garnered significant attention, owing to their remarkable efficiency. Methylammonium chloride (MACl), a common additive, is used to control the crystallization of FAPbI 3 , thereby facilitating the formation of the photoactive α-phase. However, MACl's high volatility raises concerns regarding its stability and potential impact on the stability of the device. In this study, we partially substituted MACl with n -propylammonium chloride (PACl), which has a long alkyl chain, to promote the oriented crystallization of FAPbI 3 , ultimately forming an δ-phase-free perovskite. The FAPbI 3 film containing PACl demonstrates an enhanced photoluminescence intensity and lifetime. Additionally, PACl's presence at grain boundaries acts as a protective layer for the PSCs. Consequently, we achieved a power conversion efficiency (PCE) of 22.4% and exceptional stability. It maintains over 95% of initial PCE for 100 days in an N 2 glovebox, over 85% after 100 h of maximum power point tracking, and over 80% after 60 °C thermal aging.

Ultrathin MXene-based films exhibit superior conductivity and high capacitance, showing promise as electrodes for flexible supercapacitors. This work describes a simple method to enhance the performance of MXene-based supercapacitors by expanding and stabilizing the interlayer space between MXene flakes while controlling the functional groups to improve the conductivity. Ti 3 C 2 T x MXene flakes are treated with bacterial cellulose (BC) and NaOH to form a composite MXene/BC (A-M/BC) electrode with a microporous interlayer and high surface area (62.47 m 2 g -1 ). Annealing the films at low temperature partially carbonizes BC, increasing the overall electrical conductivity of the films. Improvement in conductivity is also attributed to the reduction of -F, -Cl, and -OH functional groups, leaving -Na and -O functional groups on the surface. As a result, the A-M/BC electrode demonstrates a capacitance of 594 F g -1 at a current density of 1 A g -1 in 3 M H 2 SO 4 , which represents a ∼2× increase over similarly processed films without BC (309 F g -1 ) or pure MXene (298 F g -1 ). The corresponding device has an energy density of 9.63 Wh kg -1 at a power density of 250 W kg -1 . BC is inexpensive and enhances the overall performance of MXene-based film electrodes in electronic devices. This method underscores the importance of functional group regulation in enhancing MXene-based materials for energy storage.

In tropical and developing countries, mosquito-borne diseases by flaviviruses pose a serious threat to public health. Early detection is critical for preventing their spread, but conventional methods are time-consuming and require skilled technicians. Biosensors have been developed to address this issue, but cross-reactivity with other flaviviruses remains a challenge. Peptides are essentially biomaterials used in diagnostics that allow virological and serological techniques to identify flavivirus selectively. This biomaterial originated as a small protein consisting of two to 50 amino acid chains. They offer flexibility in chemical modification and can be easily synthesized and applied to living cells in the engineering process. Peptides could potentially be developed as robust, low-cost, sensitive, and selective receptors for detecting flaviviruses. However, modification and selection of the receptor agents are crucial to determine the effectiveness of binding between the targets and the receptors. This paper addresses two potential peptide nucleic acids (PNAs) and affinity peptides that can detect flavivirus from another target-based biosensor as well as the potential peptide behaviors of flaviviruses. The PNAs detect flaviviruses based on the nucleotide base sequence of the target's virological profile via Watson-Crick base pairing, while the affinity peptides sense the epitope or immunological profile of the targets. Recent developments in the functionalization of peptides for flavivirus biosensors are explored in this Review by division into electrochemical, optical, and other detection methods.

In this work, simple and sensitive detection of dengue virus serotype-3 (DENV-3) antigen was accomplished by a one-dimensional (1D) HKUST-1-functionalized electrochemical sensor. 1D HKUST-1 was synthesized via a coprecipitation method using triethanolamine (TEOA) as pH modulator and structure-directing agent. The structure, morphology, and sensing performance of the HKUST-1-decorated carbon electrode were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). We found that 40 wt% TEOA transforms the octahedron HKUST-1 to the nanorods while maintaining its crystal structure and providing chemical stability. The 1D HKUST-1-decorated carbon electrode successfully detects the antigen in the range of 0.001-10 ng/mL with a detection limit of 0.932 pg/mL. The immunosensor also exhibits remarkable performance in analyzing the antigen in human serum and showed recovery as high as ∼98% with excellent selectivity and reproducibility., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

This study reports on the modification of surface plasmon resonance (SPR) chips with molybdenum disulfide-molybdenum trioxide (MoS 2 -MoO 3 ) microflowers to detect the tuberculosis (TB) markers of CFP-10. The MoS 2 -MoO 3 microflowers were prepared by hydrothermal methods with variations in the pH and amount of trisodium citrate (Na 3 Ct), which were projected to influence the shape and size of microflower particles. The analysis shows that optimum MoS 2 -MoO 3 hybrid microflowers were obtained at neutral pH using 0.5 g Na 3 Ct. The modified SPR biosensor exhibits a ten times higher response than the bare Au. Moreover, increasing MoS 2 -MoO 3 thickness results in a higher detection response, sensitivity, and a smaller limit of detection (LOD). Using the optimized material composition, the Au/MoS 2 -MoO 3 -integrated SPR sensor can demonstrate sensitivity and LOD of 1.005 and 3.45 ng mL -1 , respectively. This biosensor also has good selectivity, stability, and reproducibility based on cross-sensitivity characterization with other analytes and repeated measurements on several chips with different storing times and fabrication batch. Therefore, this proposed SPR biosensor possesses high potential to be further developed and applied as a detection technology for CFP-10 in monitoring and diagnosing TB.

This work presents a high-performance surface plasmon resonance (SPR)-based biosensor for glucose detection. While adding a metal-organic framework (MOF) layer, UiO-66, to the biosensor improves selectivity and enables direct detection without additional receptors, it does not significantly enhance sensitivity. A SPR-based biosensor is proposed to overcome this limitation by introducing a layer of 2D-transition metal dichalcogenides (2D-TMD) and decorating the UiO-66 structure with gold nanoparticles (UiO-66AuNP). The optical properties of the biosensor for glucose detection in urine are investigated by employing the finite difference time domain (FDTD) method with Kretschmann configuration at a wavelength of 633 nm, and its performance is effectively improved by incorporating 2D-TMD and AuNP layers into the biosensor structure. Notably, the SPR-based biosensor with the decorated UiO-66 layer exhibits a further change in the SPR angle in the presence of glucose-containing urine. Using computational studies, various performance parameters, such as the biosensors' signal-to-noise ratio (SNR) and quality factor (QF), are evaluated in addition to sensitivity. The maximum sensitivity achieved is 309.3°/RIU for the BK7/Ag/PtSe2/WSe2/MoS2/UiO-66AuNP/sensing medium structure. The exceptional performance of the proposed biosensor structure demonstrates its suitability for precise glucose detection in urine while also opening new avenues for developing bioreceptor-free SPR-based sensors., (© 2023 IOP Publishing Ltd.)

KCC-1, a nanostructured silica material with a bicontinuous concentric lamellar (bcl) morphology, provides plenty of functional characteristics, such as an open channel structure, excellent accessibility, and a large surface area. Although bcl silica exhibits various superior properties, studies on its morphology and its application in dye-sensitized solar cells (DSSCs) are still limited. Therefore, this work aims to study the influence of the synthesis time on the morphology of bcl silica. Moreover, we used the synthesized bcl silica as internal micro-reflectors in DSSCs. The bcl silica was synthesized using the reflux method by varying synthesis times. The morphology of bcl silica was observed using FESEM and HRTEM. FESEM images show that bcl silica has bicontinuous lamellar walls arranged concentrically to form spherical particles. As the synthesis time increases, the average particle size of bcl silica increases. The quantization of bcl silica binary images shows that the average lamellar cross-sectional area ratio decreases with increasing synthesis time. The simulation of the Cahn-Hilliard's spinodal decomposition model using MATLAB also describes the lamellar cross-sectional area ratio of bcl silica. In addition, to characterize the FESEM image's texture, a Shannon entropy calculation was performed. The line and circular gray value intensity profiles of the HRTEM image show that bcl silica has a denser core than the outer part. The denser core proves that the lamellae in bcl silica are concentrically arranged towards the particle core. Furthermore, we added bcl silica to a photoanode to see the effect of bcl characteristics on the DSSC performance. The results show that the bcl silica significantly improves the light-harvesting efficiency in DSSCs due to its low refractive index and open channel structure.

The poor cycling stability of faradaic materials owing to volume expansion and stress concentration during faradaic processes limits their use in large-scale electrochemical deionization (ECDI) applications. Herein, we developed a "soft-hard" interface by introducing conducting polymer hydrogels (CPHs), that is, polyvinyl alcohol/polypyrrole (PVA/PPy), to support the uniform distribution of Prussian blue analogues ( e.g. , copper hexacyanoferrate (CuHCF)). In this design, the soft buffer layer of the hydrogel effectively alleviates the stress concentration of CuHCF during the ion-intercalation process, and the conductive skeleton of the hydrogel provides charge-transfer pathways for the electrochemical process. Notably, the engineered CuHCF@PVA/PPy demonstrates an excellent salt-adsorption capacity of 22.7 mg g -1 at 10 mA g -1 , fast salt-removal rate of 1.68 mg g -1 min -1 at 100 mA g -1 , and low energy consumption of 0.49 kW h kg -1 . More importantly, the material could maintain cycling stability with 90% capacity retention after 100 cycles, which is in good agreement with in situ X-ray diffraction tests and finite element simulations. This study provides a simple strategy to construct three-dimensional conductive polymer hydrogel structures to improve the desalination capacity and cycling stability of faradaic materials with universality and scalability, which promotes the development of high-performance electrodes for ECDI.

Friedel-Crafts acylation of dipyrromethane with cinnamoyl chloride was conducted to obtain dicinnamoyl dipyrromethane compounds 3 and 4. Both compounds were subsequently oxidized by DDQ to produce dicinnamoyl dipyrromethene ligands (DC-1 and DC-2). A large bathochromic shift compared to dipyromethene (D) was observed at 95 nm for DC-1 and 67 nm for DC-2. Both compounds showed remarkable chelation-enhanced fluorescence (CHEF) upon addition of zinc(II) ions. Similar to the quadrupolar system, DC-1 exhibited absorption and emission near the optical windows of the tissue. However, asymmetrical DC-2 had a better "turn-on" CHEF, with a fluorescence intensity that was 22 times higher than that of compound D. The DC-2 ligand also showed a limit of detection (LOD) of up to 3.0×10 -8  M and selectivity toward zinc(II) ions compared to alkali and alkaline earth metal ions., (© 2023 Wiley-VCH GmbH.)

The gold layer on the surface plasmon resonance (SPR) sensor chip cannot detect small molecules, such as glucose without the use of specific receptors. Metal-organic frameworks (MOFs) are useful in biosensing technologies for capturing and co-localizing enzymes and receptors with the target biomolecule. In many previous studies, the properties of the MOFs were often ignored, with these studies focusing on the selection of appropriate receptors. To take advantage of the unique properties of MOFs in biosensors, one must also consider the technique and transducer used because these aspects will strongly influence the detection mechanism. In this work, we have investigated for the first time, the applications of hierarchical metal-BDC (M-BDC) MOFs for glucose detection using the SPR technique without the use of specific receptors. The underlying interactions and adsorption mechanisms were analyzed using adsorption isotherm and kinetic models. The sensing measurements show that the SPR chips functionalized with M-BDC MOFs exhibit higher sensitivity and lower limit of detection (LOD). Specifically, the sensitivity follows the order of Zr-BDC > Cu-BDC > Mn-BDC > Ni-BDC > bare Au SPR chips with the LOD in the order of Zr-BDC < Mn-BDC < Ni-BDC < Cu-BDC < bare Au SPR chips. The selectivity test results reveal that Zr-BDC exhibits a decent selectivity to glucose in the presence of other interfering compounds, such as ascorbic acid, uric acid, maltose, and urea. These results demonstrate the promising potential of MOFs for SPR biosensing.

TiO 2 particles with a specific morphology are essential for their accessibility and photoactivity. The present study shows that NH 4 OH-based alkaline-hydrothermal treatment affects the transformation of their particle morphology. We investigated the effect of NH 4 OH by varying the synthesis route. We observed that the TiO 2 particles with an open channel pore structure only resulted in the alkaline-hydrothermally treated and calcined samples. Based on Raman and XRD analyses, we figured out the titanate layers as an intermediate phase resulting from the alkaline-hydrothermal treatment of the amorphous particles. The hydrothermal treatment changed the particle surface morphology into a lamellar structure with a high specific surface area. These are the anatase precursors with {200} planes that transform into the anatase phase after calcination. The calcination followed by alkaline-hydrothermal treatment converted the crystallinity without significantly changing their morphology. We found that the morphology of TiO 2 particles can be modified via hydrothermal treatment using NH 4 OH as long as the particles remain uncrystallized. We suggested the modification of particle morphology through the swelling and phase segregation process by alkaline-hydrothermal treatment. All final products have been used for the photodegradation of rhodamine B. S-HT-500 and A-HT-500 show the best photocatalytic activity with their rate constants ( k ) of 47.9 and 30.9 × 10 -2 min -1 , and their surface area-normalized rate constants ( k sa ) of 6.5 and 2.6 × 10 -3 L m -2 min -1 , respectively, and have a photocatalytic efficiency of 90.93% and 67.78%, respectively, after 10 minutes of UV irradiation. This activity is approximately 3.5 times and 1.5 times higher than that of Degussa P25; 30 times and 20 times higher than that without a photocatalyst.

Fluorescent Carbon dots (CDs) derived from biologically active sources have shown enhanced activities compared to their precursors. With their prominent potentiality, these small-sized (<10nm) nanomaterials could be easily synthesized from organic sources either by bottom-up or green approach. Their sources could influence the functional groups present on the CDs surfaces. A crude source of organic molecules has been used to develop fluorescent CDs. In addition, pure organic molecules were also valuable in developing practical CDs. Physiologically responsive interaction of CDs with various cellular receptors is possible due to the robust functionalization on their surface. In this review, we studied various literatures from the past ten years that reported the potential application of carbon dots as alternatives in cancer chemotherapy. The selective cytotoxic nature of some of the CDs towards cancer cell lines suggests the role of surface functional groups towards selective interaction, which results in over-expressed proteins characteristic of cancer cell lines. It could be inferred that cheaply sourced CDs could selectively bind to overexpressed proteins in cancer cells with the ultimate effect of cell death induced by apoptosis. In most cases, CDs-induced apoptosis directly or indirectly follows the mitochondrial pathway. Therefore, these nanosized CDs could serve as alternatives to the current kinds of cancer treatments that are expensive and have numerous side effects., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Two years after SARS-CoV-2 caused the first case of COVID-19, we are now in the "new normal" period, where people's activity has bounced back, followed by the easing of travel policy restrictions. The lesson learned is that the wide availability of accurate and rapid testing procedures is crucial to overcome possible outbreaks in the future. Therefore, many laboratories worldwide have been racing to develop a new point-of-care diagnostic test. To aid continuous innovation, we developed a plasmonic-based biosensor designed explicitly for portable Surface Plasmon Resonance (SPR). In this study, we designed a single chain variable fragment (scFv) from the CR3022 antibody with a particular linker that inserted a cysteine residue at the second position. It caused the linker to have a strong affinity to the gold surface through thiol-coupling and possibly become a ready-to-use bioreceptor toward a portable SPR gold chip without purification steps. The theoretical affinity of this scFv on spike protein was -64.7 kcal/mol, computed using the Molecular Mechanics Generalized Born Surface Area (MM/GBSA) method from the 100 ns molecular dynamics trajectory. Furthermore, the scFv was produced in Escherichia coli BL21 (DE3) as a soluble protein. The binding activity toward Spike Receptor Binding Domain (RBD) SARS-CoV-2 was confirmed with a spot-test, and the experimental binding free energy of -10.82 kcal/mol was determined using portable SPR spectroscopy. We hope this study will be useful in designing specific and low-cost bioreceptors, particularly early in an outbreak when the information on antibody capture is still limited., Competing Interests: The authors declare no conflicts of interest.

We demonstrated potential features of gold nanoparticle bipyramid (AuNB) for an electrochemical biosensor. The facile synthesis method and controllable shape and size of the AuNB are achieved through the optimization of cetyltrimethylammonium chloride (CTAC) surfactant over citric acid (CA) ratio determining the control of typically spherical Au seed size and its transition into a penta-twinned crystal structure. We observe that the optimized ratio of CTAC and CA facilitates flocculation control in which Au seeds with size as tiny as ∼14.8 nm could be attained and finally transformed into AuNB structures with an average length of ∼55 nm with high reproducibility. To improve the electrochemical sensing performance of a screen-printed carbon electrode, surface modification with AuNB via distinctive linking procedures effectively enhanced the electroactive surface area by 40%. Carried out for the detection of dopamine, a neurotransmitter frequently linked to the risk of Parkinson's, Alzheimer's, and Huntington's diseases, the AuNB decorated-carbon electrode shows outstanding electrocatalytic activity that improves sensing performance, including high sensitivity, low detection limit, wide dynamic range, high selectivity against different analytes, such as ascorbic acid, uric acid and urea, and excellent reproducibility., (Creative Commons Attribution license.)

Exploration of advanced carbon anode material is the key to circumventing the sluggish kinetics and poor rate capability for potassium ion storage. Herein, a synergistic synthetic strategy of engineering both surface and structure is adopted to design N, S co-doped carbon nanotubes (NS-CNTs). The as-designed NS-CNTs exhibit unique features of defective carbon surface, hollow tubular channel, and enlarged interlayer space. These features significantly contribute to a large potassium storage capacity of 307 mA h g -1 at 1 A g -1 and a remarkable rate performance with a capacity of 151 mA h g -1 even at 5 A g -1 . Furthermore, an excellent cyclability with 98% capacity retention after 500 cycles at 2 A g -1 is also achieved. Systematic analysis by in situ Raman spectroscopy and ex situ TEM demonstrates the structural stability and reversibility in the charge-discharge process. Although the kinetics studies reveal the capacitive-dominated process for potassium storage, density functional theory calculations provide evidence that N, S co-doping contributes to expanding the interlayer space to promote the K-ion insertion, improving the electronic conductivity, and providing ample defective sites to favor the K-ion adsorption., (© 2022 The Authors. Small published by Wiley-VCH GmbH.)

Poly(3,4-ethylenedioxythiophene) (PEDOT) is a prime example of conducting polymer materials for supercapacitor electrodes that offer ease of processability and sophisticated chemical stability during operation and storage in aqueous environments. Yet, continuous improvement of its electrochemical capacitance and stability upon long cycles remains a major interest in the field, such as developing PEDOT-based composites. This work evaluates the electrochemical performances of hydroxymethyl PEDOT (PEDOTOH) coupled with hydrogel additives, namely poly(ethylene oxide) (PEO), poly(acrylic acid) (PAA), and polyethyleneimine (PEI), fabricated via a single-step electrochemical polymerization method in an aqueous solution. The PEDOTOH/PEO composite exhibits the highest capacitance (195.2 F g -1 ) compared to pristine PEDOTOH (153.9 F g -1 ), PEDOTOH/PAA (129.9 F g -1 ), and PEDOTOH/PEI (142.3 F g -1 ) at a scan rate of 10 mV s -1 . The PEDOTOH/PEO electrodes were then assembled into a symmetrical supercapacitor in an agarose gel. The type of supporting electrolytes and salt concentrations were further examined to identify the optimal agarose-based gel electrolyte. The supercapacitors comprising 2 M agarose-LiClO 4 achieved a specific capacitance of 27.6 F g -1 at a current density of 2 A g -1 , a capacitance retention of ∼94% after 10,000 charge/discharge cycles at 10.6 A g -1 , delivering a maximum energy and power densities of 11.2 Wh kg -1 and 17.28 kW kg -1 , respectively. The performance of the proposed supercapacitor outperformed several reported PEDOT-based supercapacitors, including PEDOT/carbon fiber, PEDOT/CNT, and PEDOT/graphene composites. This study provides insights into the effect of incorporated hydrogel in the PEDOTOH network and the optimal conditions of agarose-based gel electrolytes for high-performance PEDOT-based supercapacitor devices., (© 2022 Wiley-VCH GmbH.)

This study reports for the first time the surface modification of fluorescent nanoparticles derived from geothermal silica precipitate with Escherichia coli ( E. coli ) antibody. The immobilization of biomolecules on the inorganic surface has been carried out using two different pathways, namely the silanization and hydrosilylation reactions. The former applied (3-aminopropyl)triethoxysilane (APTES) as the crosslinker, while the latter used N -hydroxysuccinimide coupled with N -ethyl- N '-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC/NHS). Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX), and fluorescence spectroscopy were used to confirm the chemical, physical, and optical properties of the surface-modified fluorescent silica nanoparticles (FSNPs). Based on the results of the FTIR, fluorescence spectroscopy and stability tests, the modified FSNPs with EDC/NHS with a ratio of 4 : 1 were proven to provide the optimum results for further conjugation with antibodies, affording the FSNP-Ab2 sample. The FSNP-Ab2 sample was further tested as a nanoplatform for the fluorescence-quenching detection of E. coli , which provided a linear range of 10 2 to 10 7 CFU mL -1 for E. coli with a limit of detection (LoD) of 1.6 × 10 2 CFU mL -1 . The selectivity of the biosensor was observed to be excellent for E. coli compared to that for P. aeruginosa and S. typhimurium , with reductions in the maximum fluorescence intensity at 588 nm of 89.22%, 26.23%, and 54.06%, respectively. The inorganic nanostructure-biomolecule conjugation with optimized coupling agents showed promising analytical performance as a selective nanoplatform for detecting E. coli bacteria., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Thermal signature reduction in camouflage textiles is a vital requirement to protect soldiers from detection by thermal imaging equipment in low-light conditions. Thermal signature reduction can be achieved by decreasing the surface temperature of the subject by using a low thermally conductive material, such as polycarbonate, which contains bisphenol A. Polycarbonate is a hard type of plastic that generally ends up in dumps and landfills. Accordingly, there is a large amount of polycarbonate waste that needs to be managed to reduce its drawbacks to the environment. Polycarbonate waste has great potential to be used as a material for recycled fibre by the melt spinning method. In this research, polycarbonate roofing-sheet waste was extruded using a 2 mm diameter of spinnerette and a 14 mm barrel diameter in a 265 °C temperature process by using a lab-scale melt spinning machine at various plunger and take-up speeds. The fibres were then inserted into 1 × 1 rib-stitch knitted fabric made by Nm 15 polyacrylic commercial yarns, which were manufactured by a flat knitting machine. The results showed that applying recycled polycarbonate fibre as a fibre insertion in polyacrylic knitted fabric reduced the emitted infrared and thermal signature of the fabric.

Borophene, a monolayer of boron, has risen as a new exciting two-dimensional (2D) material having extraordinary properties, including anisotropic metallic behavior and flexible (orientation-dependent) mechanical and optical properties. This review summarizes the current progress in the synthesis of borophene on various metal substrates, including Ag(110), Ag(100), Au(111), Ir(111), Al(111), and Cu(111), as well as heterostructuring of borophene. In addition, it discusses the mechanical, thermal, magnetic, electronic, optical, and superconducting properties of borophene and the effects of elemental doping, defects, and applied mechanical strains on these properties. Furthermore, the promising potential applications of borophene for gas sensing, energy storage and conversion, gas capture and storage applications, and possible tuning of the material performance in these applications through doping, formation of defects, and heterostructures are illustrated based on available theoretical studies. Finally, research and application challenges and the outlook of the whole borophene's field are given.

Molybdenum-based materials have been intensively investigated for high-performance gas sensor applications. Particularly, molybdenum oxides and dichalcogenides nanostructures have been widely examined due to their tunable structural and physicochemical properties that meet sensor requirements. These materials have good durability, are naturally abundant, low cost, and have facile preparation, allowing scalable fabrication to fulfill the growing demand of susceptible sensor devices. Significant advances have been made in recent decades to design and fabricate various molybdenum oxides- and dichalcogenides-based sensing materials, though it is still challenging to achieve high performances. Therefore, many experimental and theoretical investigations have been devoted to exploring suitable approaches which can significantly enhance their gas sensing properties. This review comprehensively examines recent advanced strategies to improve the nanostructured molybdenum-based material performance for detecting harmful pollutants, dangerous gases, or even exhaled breath monitoring. The summary and future challenges to advance their gas sensing performances will also be presented., (© 2021. The Author(s).)

The introduction of defects into hierarchical porous metal-organic frameworks (HP-MOFs) is of vital significance to boost their adsorption performance. Herein, an advanced template-assisted strategy has been developed to fine-tune the phosphate adsorption performance of HP-MOFs by dictating the type and number of defects in HP-UiO-66(Zr). To achieve this, monocarboxylic acids of varying chain lengths have been employed as template molecules to fabricate an array of defect-rich HP-UiO-66(Zr) derivatives following removal of the template. The as-prepared HP-UiO-66(Zr) exhibits a higher sorption capacity and faster sorption rate compared to the pristine UiO-66(Zr). Particularly, the octanoic acid-modulated UiO-66(Zr) exhibits a high adsorption capacity of 186.6 mg P/g and an intraparticle diffusion rate of 6.19 mg/g·min 0.5 , which are 4.8 times and 1.9 times higher than those of pristine UiO-66(Zr), respectively. The results reveal that defect sites play a critical role in boosting the phosphate uptake performance, which is further confirmed by various advanced characterizations. Density functional theory (DFT) calculations reveal the important role of defects in not only providing additional sorption sites but also reducing the sorption energy between HP-UiO-66(Zr) and phosphate. In addition, the hierarchical pores in HP-UiO-66(Zr) can accelerate the phosphate diffusion toward the active sorption sites. This work presents a promising route to tailor the adsorption performance of MOF-based adsorbents via defect engineering.

Metal-organic framework (MOF) nanomaterials offer a wide range of promising applications due to their unique properties, including open micro- and mesopores and richness of functionalization. Herein, a facile synthesis via a solvothermal method was successfully employed to prepare amine-functionalized Cu-MOF nanospheres. Moreover, the growth and the morphology of the nanospheres were optimized by the addition of PVP and TEA. By functionalization with an amine group, the immobilization of a bioreceptor towards the detection of hepatitis B infection biomarker, i.e., hepatitis B surface antigen (HBsAg), could be realized. The immobilization of the bioreceptor/antibody to Cu-MOF nanospheres was achieved through a covalent interaction between the carboxyl group of the antibodies and the amino-functional ligand in Cu-MOF via EDC/NHS coupling. The amine-functionalized Cu-MOF nanospheres act not only as a nanocarrier for antibody immobilization, but also as an electroactive material to generate the electrochemical signal. The electrochemical sensing performance was characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The results showed that the current response proportionally decreased with the increase of HBsAg concentration. More importantly, the sensing performance of the amine-functionalized Cu-MOF nanospheres towards HBsAg detection was found to be consistent in real human serum media. This strategy successfully resulted in wide linear range detection of HBsAg from 1 ng mL-1 to 500 ng mL-1 with a limit of detection (LOD) of 730 pg mL-1. Thus, our approach provides a facile and low-cost synthesis process of an electrochemical immunosensor and paves the way to potentially utilize MOF-based nanomaterials for clinical use.

Conductive polymers (CPs) integrate the inherent characteristics of conventional polymers and the unique electrical properties of metals. They have aroused tremendous interest over the last decade owing to their high conductivity, robust and flexible properties, facile fabrication, and cost-effectiveness. Compared to bulk CPs, porous CPs with well-defined nano- or microstructures possess open porous architectures, high specific surface areas, more exposed reactive sites, and remarkably enhanced activities. These attractive features have led to their applications in sensors, energy storage and conversion devices, biomedical devices, and so on. In this review article, the different strategies for synthesizing porous CPs, including template-free and template-based methods, are summarized, and the importance of tuning the morphology and pore structure of porous CPs to optimize their functional performance is highlighted. Moreover, their representative applications (energy storage devices, sensors, biomedical devices, etc.) are also discussed. The review is concluded by discussing the current challenges and future development trend in this field., (© 2021 Wiley-VCH GmbH.)

The present study explores the potential of carbon nanodots (CDs) synthesized from hyaluronic acid using microwave-assisted and furnace-assisted methods as bioimaging agents for cancer cells. The investigation on the effect of microwave-assisted and furnace-assisted times (2 min and 2 h) on determining CD character is dominantly discussed. Various CDs, such as HA-P1 and HA-P2 were, respectively, synthesized through the furnace-assisted method at 270 °C for 2 min and 2 h, whereas HA-M1 and HA-M2 were synthesized with the microwave-assisted method for 2 min and 2 h, respectively. Overall, various CDs were produced with an average diameter, with the maximum absorption of HA-P1, HA-P2, HA-M1, and HA-M2 at 234, 238, 221, and 217 nm, respectively. The photoluminescence spectra of these CDs showed particular emissions at 320 nm and excitation wavelengths from 340 to 400 nm. Several characterizations such as X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy reveal the CD properties such as amorphous structures, existence of D bands and G bands, and hydrophilic property supported with hydroxyl and carboxyl groups. The quantum yields of HA-M1, HA-M2, HA-P1, and HA-P2 were 12, 7, 9, and 23%, respectively. The cytotoxicity and in vitro activity were verified by a cell counting kit-8 assay and confocal laser scanning microscopy, which show a low toxicity with the percentage of living cells above 80%., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

In the past two decades, mesoporous TiO2 has emerged as a promising material for biosensing applications. In particular, mesoporous TiO2 materials with uniform, well-organized pores and high surface areas typically exhibit superior biosensing performance, which includes high sensitivity, broad linear response, low detection limit, good reproducibility, and high specificity. Therefore, the development of biosensors based on mesoporous TiO2 has significantly intensified in recent years. In this review, the expansion and advancement of mesoporous TiO2-based biosensors for glucose detection, hydrogen peroxide detection, alpha-fetoprotein detection, immobilization of enzymes, proteins, and bacteria, cholesterol detection, pancreatic cancer detection, detection of DNA damage, kanamycin detection, hypoxanthine detection, and dichlorvos detection are summarized. Finally, the future perspective and research outlook on the utilization of mesoporous TiO2-based biosensors for the practical diagnosis of diseases and detection of hazardous substances are also given.

Concave metallic nanocrystals with a high density of low-coordinated atoms on the surface are essential for the realization of unique catalytic properties. Herein, mesoporous palladium nanocrystals (MPNs) that possess various degrees of curvature are successfully synthesized following an approach that relies on a facile polymeric micelle assembly approach. The as-prepared MPNs exhibit larger surface areas compared to conventional Pd nanocrystals and their nonporous counterparts. The MPNs display enhanced electrocatalytic activity for ethanol oxidation when compared to state-of-the-art commercial palladium black and conventional palladium nanocubes used as catalysts. Interestingly, as the degree of curvature increases, the surface-area-normalized activity also increases, demonstrating that the curvature of MPNs and the presence of high-index facets are crucial considerations for the design of electrocatalysts.

This work contributes to combining 12.2 mM purified anthocyanin of cyanidin-3-glucoside extracted from Indonesian black rice as the natural pigment with a ruthenium photosensitizer (1 : 1) in dye-sensitized solar cells (DSSCs) in liquid and quasi solid-state electrolytes. The findings essentially highlight the spectroscopic and electron transfer mechanism for the future trend of D-π-A natural pigment modification. The complete pigment comparison, dye absorbance, dye adsorption onto the semiconductor, dye electronic properties, electron excitation, and regeneration were investigated using spectroscopic methods. Cells employ TiO 2 mesoporous nanoparticles (19.18 nm grain size, 50.99 m 2 g -1 surface area, 87.8% anatase 12.2% rutile, 10.58 μm thickness, 3.18 eV band gap) sensitized by anthocyanin-N719 photosensitizer (12.2 mM) with the I - /I 3 - electrolyte (0.1 M lithium iodide/0.05 M iodine/0.6 M 1-buty-3-methylimidazolium iodide/0.5 M 4- tert -butylpyridine/polyethylene oxide M w = 1 × 10 6 ) - Pt film. As a result, the quasi-solid state with combined anthocyanin-ruthenium dye-sensitized solar cell (3.51%) is achieved and reported for the first time. The work also achieved the highest efficiency of the anthocyanin dye-sensitized quasi-solid state solar cells of 2.65%. The insight on how the combined anthocyanin-N719 and the quasi-solid state electrolytes exhibit better performances will be further discussed., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Layered double hydroxides (LDHs) containing first-row transition metals such as Fe, Co, and Ni have attracted significant interest for electrocatalysis owing to their abundance and excellent performance for the oxygen evolution reaction (OER) in alkaline media. Herein, the assembly of holey iron-doped nickel-cobalt layered double hydroxide (NiCo-LDH) nanosheets ('holey nanosheets') is demonstrated by employing uniform Ni-Co glycerate spheres as self-templates. Iron doping was found to increase the rate of hydrolysis of Ni-Co glycerate spheres and induce the formation of a holey interconnected sheet-like structure with small pores (1-10 nm) and a high specific surface area (279 m 2  g -1 ). The optimum Fe-doped NiCo-LDH OER catalyst showed a low overpotential of 285 mV at a current density of 10 mA cm -2 and a low Tafel slope of 62 mV dec -1 . The enhanced OER activity was attributed to (i) the high specific surface area of the holey nanosheets, which increases the number of active sites, and (ii) the improved kinetics and enhanced ion transport arising from the iron doping and synergistic effects., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Two-dimensional metal-organic frameworks (2D MOFs) are an attractive platform to develop new kinds of catalysts because of their structural tunability and large specific surface area that exposes numerous active sites. In this work, we report a general method to synthesize benzene dicarboxylic acid (BDC)-based MOFs with hierarchical 3D morphologies composed of 2D nanosheets or nanoplates. In our proposed strategy, acetonitrile helps solvate the metal ions in solution and affects the morphology, while polyvinylpyrrolidone (PVP) serves as a shape-control agent to assist in the nucleation and growth of MOF nanosheets. PVP also acts as a depletion agent to drive the assembly of the hierarchical sheet/plate-like M-BDC under solvothermal conditions. Further, we also demonstrate the flexibility of the proposed method using numerous coordinating metal ions (M = Cu, Mn, Ni, and Zr). The potential of these MOFs for electrochemical glucose sensing is examined using the hierarchical sheet-like Ni-BDC MOF as the optimum sample. It drives the electrocatalytic oxidation of glucose over a wide range (0.01 mM to 0.8 mM) with high sensitivity (635.9 μA mM -1 cm -2 ) in the absence of modification with carbon or the use of conductive substrates. It also demonstrates good selectivity with low limit of detection (LoD = 6.68 μM; signal/noise = 3), and fast response time (<5 s)., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Mesoporous metals have attracted a lot of interest due to their wide range of applications, particularly in catalysis. We previously reported the preparation of mesoporous Pd using block copolymer micelle templates ( Chem. Sci. 2019 , 10 , 4054). Here we extend this synthetic concept to generate alloyed spherical palladium-copper (PdCu) nanoparticles with an open porous network and uniform morphology. This one-pot synthesis is initiated by water-induced micellization of the block copolymer, followed by the chemical reduction, nucleation, and growth of mesoporous spherical alloy nanoparticles. Porosity enables accessibility to numerous active sites throughout the interior and exterior surfaces of the nanoparticles. Mesoporous nanoparticles composed of Pd and Cu alloy exhibit enhanced electrocatalytic activity and stability in the ethanol oxidation reaction (EOR) and the oxygen reduction reaction (ORR).

Aim: Time-based microfluidic absorption sampling was proposed using cotton fiber-based device made in swab stick. The assay was optimized and compared with conventional pipetted drop sampling using the same device. Materials & methods: Reagents were integrated into cotton fiber device for assessing concentration of analytes by the colorimetric detection method through time-based absorption sampling microfluidic system. All assay parameters were first optimized using conventional pipette-based drop sampling. Results: The color intensity is linear in the relevant concentration range of the analytes. The LOD are 0.189 mM for glucose and 6.56 μM for nitrite, respectively. These values are better than conventional drop sampling. The fiber-containing swab itself functions as sampling, assay and calibration device. Conclusion: Microfluidic cotton fiber-based assay device was fabricated and can determine analyte concentration in artificial salivary samples, colorimetrically, by time-based absorption sampling without the need of complex equipments.

The effective utilization of various biomolecules for creating a series of mesoporous boehmite (γ-AlOOH) and gamma-alumina (γ-Al 2 O 3 ) nanosheets with unique hierarchical multilayered structures is demonstrated. The nature and concentration of the biomolecules strongly influence the degree of the crystallinity, the morphology, and the textural properties of the resulting γ-AlOOH and γ-Al 2 O 3 nanosheets, allowing for easy tuning. The hierarchical γ-AlOOH and γ-Al 2 O 3 multilayered nanosheets synthesized by using biomolecules exhibit enhanced crystallinity, improved particle separation, and well-defined multilayered structures compared to those obtained without biomolecules. More impressively, these γ-AlOOH and γ-Al 2 O 3 nanosheets possess high surface areas up to 425 and 371 m 2  g -1 , respectively, due to their mesoporous nature and hierarchical multilayered structure. When employed for molybdenum adsorption toward medical radioisotope production, the hierarchical γ-Al 2 O 3 multilayered nanosheets exhibit Mo adsorption capacities of 33.1-40.8 mg g -1 . The Mo adsorption performance of these materials is influenced by the synergistic combination of the crystallinity, the surface area, and the pore volume. It is expected that the proposed biomolecule-assisted strategy may be expanded for the creation of other 3D mesoporous oxides in the future., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The recent development of nanoscale fillers, such as carbon nanotubes, graphene, and nanocellulose, allows the functionality of polymer nanocomposites to be controlled and enhanced. However, conventional synthesis methods of polymer nanocomposites cannot maximise the reinforcement of these nanofillers at high filler content. Approaches for the synthesis of high content filler polymer nanocomposites are suggested to facilitate future applications. The fabrication methods address the design of the polymer nanocomposite architecture, which encompasses one, two, and three dimensional morphologies. Factors that hamper the reinforcement of nanostructures, such as alignment, dispersion of the filler and interfacial bonding between the filler and polymer, are outlined. Using suitable approaches, maximum potential reinforcement of nanoscale fillers can be anticipated without limitations in orientation, dispersion, and the integrity of the filler particle-matrix interface. High filler content polymer composites containing emerging materials such as 2D transition metal carbides, nitrides, and carbonitrides (MXenes) are expected in the future.

Palladium (Pd) plays an important role in numerous catalytic reactions, such as methanol and ethanol oxidation, oxygen reduction, hydrogenation, coupling reactions, and carbon monoxide oxidation. Creating Pd-based nanoarchitectures with increased active surface sites, higher density of low-coordinated atoms, and maximized surface coverage for the reactants is important. To address the limitations of pure Pd, various Pd-based nanoarchitectures, including alloys, intermetallics, and supported Pd nanomaterials, have been fabricated by combining Pd with other elements with similar or higher catalytic activity for many catalytic reactions. Herein, recent advances in the preparation of Pd-based nanoarchitectures through solution-phase chemical reduction and electrochemical deposition methods are summarized. Finally, the trend and future outlook in the development of Pd nanocatalysts toward practical catalytic applications are discussed., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Mesoporous bimetallic palladium (Pd) alloy films with mesochannels perpendicularly aligned to the substrate are expected to show superior electrocatalytic activity and stability. The perpendicular mesochannels allow small molecules to efficiently access the active sites located not only at the surface but also within the film because of low diffusion resistance. When compared to pure Pd films, alloying with a secondary metal such as copper (Cu) is cost-effective and promotes resistance against adventitious poisoning through intermediate reactions known to impair the electrocatalytic performance. Here, we report the synthesis of mesoporous PdCu films by electrochemical deposition in nonionic micellar solutions. The mesoporous structures are vertically aligned on the substrate, and the final content of Pd and Cu can be adjusted by tuning the initial precursor molar ratio in the electrolyte solution.

Self-ordered and structure-controlled transparent films of tin-modified mesoporous silica (Sn/Si ratio of 0.5-3%) were first prepared using a molecule surfactant template method employing spin coating. A surface photovoltage (SPV) NO(2) gas sensor was then fabricated using these self-ordered tin-modified mesoporous silica thin films based on a metal-insulator-semiconductor structure. Highly sensitive tin-modified mesoporous silica was obtained that could detect NO(2) gas concentrations of as low as 300 ppb at room temperature. The detection mechanism for NO(2) is believed to involve both the surface area, which contributes to the change in dielectric constant, and the amount of tin incorporated, which contributes to the change in charge. It was found that, in this SPV sensor, the optimal Sn/Si ratio of 0.5% delivered record-high sensing performance.