An effective utilization of MXene and its effect on electromagnetic interference shielding: flexible,free-standing and thermally conductive composite from MXene–PAT–poly(p-aminophenol)–polyaniline co-polymer

MXene and conductive polymers are attractive candidates for electromagnetic interference shielding (EMI) applications. The MXene–PAT-conductive polymer (CP) composites were fabricated by a cost-effective spray coating technique and characterized using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. A new approach has been developed for the synthesis of exfoliated MXene. The MXene–PAT–poly(p-aminophenol)–polyaniline co-polymer composite exhibited good electric conductivity (EC) of 7.813 S cm⁻¹. The composites revealed an excellent thermal properties, which were 0.687 W (m K)⁻¹ thermal conductivity, 2.247 J (g K)⁻¹ heat capacity, 0.282 mm² s⁻¹ thermal diffusivity and 1.330 W s^1/2 m⁻² K⁻¹ thermal effusivity. The composites showed 99.99% shielding efficiency and the MXene–PAT–PANI–PpAP composite (MXPATPA) had EMI shielding effectiveness of 45.18 dB at 8.2 GHz. The reduced form of MXene (r-Ti₃C₂T_x) increased the shielding effectiveness (SE) by 7.26% and the absorption (SE_A) was greatly enhanced by the ant farm like structure. The composites possess excellent thermal and EMI SE characteristics, thus can be applied in areas, such as mobile phones, military utensils, heat-emitting electronic devices, automobiles and radars.

MXene and conductive polymers are attractive candidates for electromagnetic interference shielding (EMI) applications.     

In situ polymerization of graphene-polyaniline@polyimide composite films with high EMI shielding and electrical properties

With the increasing demands of the electronics industry, electromagnetic interference (EMI) shielding has become a critical issue that severely restricts the application of devices. In this work, we have proposed a “non-covalent welding” method to fabricate graphene-polyaniline (Gr-PANI) composite fillers. The Gr sheets are welded with PANI via π–π non-covalent interactions. Furthermore, a flexible polyimide (PI) composite film with superior EMI shielding effectiveness is prepared by in situ polymerization. The 40% content of Gr-PANI_10:1 (the mass ratio of Gr to PANI is 10 : 1) shows a superior electrical conductivity (σ) as high as 2.1 ± 0.1 S cm⁻¹, 1.45 times higher than that of Gr@PI film at the same loading. Moreover, the total shielding effectiveness (SE_T) of EMI of the Gr-PANI_10:1@PI reaches ∼21.3 dB and an extremely high specific shielding effectiveness value (SSE) of 4096.2 dB cm² g⁻¹ is achieved. Such a “non-covalent welding” approach provides a facile strategy to prepare high-performance PI-based materials for efficient EMI shielding.

With the increasing demands of the electronics industry, electromagnetic interference (EMI) shielding has become a critical issue that severely restricts the application of devices.     

Ultrathin flexible graphene films with high thermal conductivity and excellent EMI shielding performance using large-sized graphene oxide flakes

As the demand for wearable and foldable electronic devices increases rapidly, ultrathin and flexible thermal conducting films with exceptional electromagnetic interference (EMI) shielding effectiveness (SE) are greatly needed. Large-sized graphene oxide flakes and thermal treatment were employed to fabricate lightweight, flexible and highly conductive graphene films. Compared to graphene films made of smaller-sized flakes, the graphene film made of large-sized flakes possesses less defects and more conjugated domains, leading to higher electrical and higher thermal conductivities, as well as higher EMI SE. By compressing four-layer porous graphene films together, a 14 μm-thick graphene film (LG-4) was obtained, possessing EMI SE of 73.7 dB and the specific SE divided by thickness (SSE/t) of 25 680 dB cm² g⁻¹. The ultrahigh EMI shielding property of the LG-4 film originates from the excellent electrical conductivity (6740 S cm⁻¹), as well as multi-layer structure composed of graphene laminates and insulated air pores. Moreover, the LG-4 film shows excellent flexibility and high thermal conductivity (803.1 W m⁻¹ K⁻¹), indicating that the film is a promising candidate for lightweight, flexible thermal conducting film with exceptional EMI shielding performance.

As the demand for wearable and foldable electronic devices increases rapidly, ultrathin and flexible thermal conducting films with exceptional electromagnetic interference (EMI) shielding effectiveness (SE) are greatly needed.     

Light weight and flexible poly(ether ether ketone) based composite film with excellent thermal stability and mechanical properties for wide-band electromagnetic interference shielding

This study proposes an efficient method for fabricating a light weight and flexible composite film with excellent thermal stability and mechanical properties for wide-band electromagnetic interference (EMI) shielding, which was prepared by melt blending and subsequent melt extrusion using poly(ether ether ketone) (PEEK) as a matrix, multi-walled carbon nanotube wrapped poly(ether sulfone) (wrapped MWCNTs) as a conductive filler, and GENIOPLAST® PELLET S (GPPS, high-temperature lubricant) as a processing aid. GPPS was firstly used in EMI application, to reduce the melt viscosity of PEEK as well as to improve the dispersion of wrapped MWCNTs, which enables it to fabricate a highly efficient EMI shielding (∼74.6 dB mm⁻¹) PEEK/wrapped MWCNT/GPPS1.0 composite film with a thickness of 180 μm. Furthermore, the lightweight composite film exhibits high thermal stability (i.e. degradation temperature at 5% mass loss of 586 °C) and good mechanical properties (tensile strength of 101 MPa), being superior to other previously reported EMI shielding films. The above mentioned enhanced property demonstrated its potential application as a high performance EMI shield for certain applications such as in the aerospace, weapons, and microelectronics industries, which require materials exhibits EMI shielding as well as superior mechanical properties and thermal stability.

Capitalizing on wrapped MWCNTs and high-temperature lubricants produce a light weight and flexible poly(ether ether ketone) composite film with excellent thermal stability and mechanical property for wide-band electromagnetic interference shielding.     

Large-scale preparation of graphene oxide film and its application for electromagnetic interference shielding

In this work, a large-scale preparation of graphene oxide (GO) film is reported, and the structure and the compositional variation was studied after thermal annealing. The electromagnetic interference (EMI) shielding performance of thermally reduced GO films was also investigated. Commercial GO clay was well dispersed by high-speed shearing and formed a stable slurry with a high solid content in water (5%), and this was chosen rather than organic solvent due to its optimal performance in coating procedures and film quality. The optimized thermal annealing procedure resulted in a significant enhancement of electric conductivity and EMI shielding efficiency, which reached 500 S cm⁻¹ and 32–42 dB with the thickness under 0.1 mm. The excellent EMI shielding efficiency of thermally reduced GO film, as well as the easily amplified pilot manufactoring procedure adaptive to commercial equipment, produce graphene for universal EMI shielding materials.

A large-scale preparation of graphene oxide (GO) film is reported, and annealing process improve the electromagnetic interference shielding performance of the film by structure and compositional variation.     

Enhanced ferromagnetism of ZnO@Co/Ni hybrid core@shell nanowires grown by electrochemical deposition method

The hybrid structure of ZnO NWs with the presence of different dopants recently has drawn many interests from researchers due to the possibility to integrate multiple functionalities into one single structure. In this article, we investigated the morphology, crystal structure and ferromagnetism of the ZnO@Co/Ni hybrid core@shell NWs prepared by a facile electrochemical deposition method. The results show that a thin layer of Ni and Co coated on the surface of ZnO NWs (confirmed by XRD, EDS, TEM and Raman scattering) can create a significant improvement of ferromagnetic property in such hybrid core@shell NWs. In which, for the coating time of 10, 15, 20 min, the value of M_s is around 0.67, 0.88 and 2.56 emu g⁻¹ for ZnO@Co NWs, and about 0.013, 0.022 and 0.031 emu g⁻¹ for ZnO@Ni NWs, respectively, in comparison with the number of 0.016 emu g⁻¹ for pure ZnO NWs. Interestingly, we also found the temperature dependence of ferromagnetism of such Co/Ni coated ZnO NWs. These results reveal the possibility to employ such hybrid core@shell NWs for many applications, e.g. spin field effect transistors.

Facile electrochemical synthesis of ZnO@Co and ZnO@Ni hybrid core@shell nanowires with enhanced ferromagnetism.     

Lightweight MWCNT/hollow mesoporous carbon/WPU composite material with excellent electromagnetic shielding performance

With the rapid increase of intelligent communication equipment, electromagnetic pollution is becoming more and more serious, and the research and application of high-performance electromagnetic shielding materials have attracted great attention from the academic and engineering circles. Traditional metal-based electromagnetic shielding materials have high reflection loss, high density, and are difficult to process. Polymer-based materials with carbon materials as fillers have the advantages of flexibility, light weight, corrosion resistance and low processing costs. They have become the most important materials in the field of electromagnetic shielding in recent years. However, the conductivity of conductive polymer materials is not high. Therefore, improving the electromagnetic shielding performance and the proportion of absorption loss under low density conditions have become key issues for polymer-based electromagnetic shielding materials. MWCNT/MCHMs/WPU composites were prepared by a solution mixing method, with 20 wt%, 40 wt%, 60 wt% MWCNTs and 40 wt% MWCNT/10 wt% MCHMs as fillers. By comparing the effects of different MWCNT content and MCHMs on the dielectric properties, electromagnetic shielding properties and mechanical properties of the MWCNT/MCHMs/WPU composites, the relationship between the structure and properties of the composites has been explored. The 0.6 mm WPU/60 wt% MWCNT composite has an electrical conductivity of 95.4 S m⁻¹ and an electromagnetic shielding effectiveness of 40 dB in the X band. Adding 10 wt% MCHMs to the WPU/40 wt% MWCNT composite material can significantly improve the composite. The δ of the material increased from 51.2 S m⁻¹ to 55.4 S m⁻¹, and the SE increased from 30 dB to 33 dB. The research results show that the increase in MWCNT content and MCHMs is beneficial to improving the electrical conductivity and electromagnetic shielding performance of the composite materials.

The interaction between electromagnetic waves and conductive fillers shielding performance.     

Efficient electromagnetic interference shielding of lightweight carbon nanotube/polyethylene composites via compression molding plus salt-leaching

Carbon nanotube/high density polyethylene (CNT/HDPE) foam composites with high electrical conductivity and electromagnetic interference (EMI) shielding performance were developed by means of compression molding plus salt-leaching. The uniform porous structure and interconnected CNT networks throughout the cell backbones endowed the as-prepared foam composites with a significantly lower electrical percolation threshold (0.22 vol%) than that of the solid composites (0.84 vol%). Owing to the multiple reflections and scattering between the cell–matrix interfaces, the foam composites presented a superior specific EMI shielding effectiveness (EMI SE) of 104.3 dB cm³ g⁻¹, 2.2 times higher than that of their solid counterpart. Besides this, the pore sizes of the CNT/HDPE foam composites could be easily tuned by controlling the particle size of the porogen. Also, the electrical conductivity and specific EMI SE increased with an increase in the cell diameter, which was attributed to the formation of a more perfect conductive network in the cell backbones. Our approach provides a novel idea for fabricating new lightweight EMI shielding materials, especially for aircraft and spacecraft applications.

Carbon nanotube/high density polyethylene foam composites with superior specific electromagnetic interference shielding effectiveness values of 104.3 dB cm³ g⁻¹ were developed via a compression molding plus salt-leaching method.     

Improved pseudocapacitive charge storage in highly ordered mesoporous TiO2/carbon nanocomposites as high-performance Li-ion hybrid supercapacitor anodes

A Li-ion hybrid supercapacitor (Li-HSCs), an integrated system of a Li-ion battery and a supercapacitor, is an important energy-storage device because of its outstanding energy and power as well as long-term cycle life. In this work, we propose an attractive material (a mesoporous anatase titanium dioxide/carbon hybrid material, m-TiO₂-C) as a rapid and stable Li⁺ storage anode material for Li-HSCs. m-TiO₂-C exhibits high specific capacity (∼198 mA h g⁻¹ at 0.05 A g⁻¹) and promising rate performance (∼90 mA h g⁻¹ at 5 A g⁻¹) with stable cyclability, resulting from the well-designed porous structure with nanocrystalline anatase TiO₂ and conductive carbon. Thereby, it is demonstrated that a Li-HSC system using a m-TiO₂-C anode provides high energy and power (∼63 W h kg⁻¹, and ∼4044 W kg⁻¹).

A mesoporous TiO₂/carbon nanocomposite prepared by block copolymer self-assembly improves pseudocapacitive behavior and achieves high energy/power density Li-ion hybrid supercapacitors.     

A self-assembled graphene/polyurethane sponge for excellent electromagnetic interference shielding performance

With the rapid development of personal computers and portable electronics, people have to get rid of a lot of unwanted electromagnetic pollution. The development of high performance electromagnetic interference (EMI) shielding materials is of critical importance to address ever-increasing military and civilian demand. Owing to its high electrical conductivity and flexible 3D structure, graphene sponge has great potential for excellent EMI shielding performance. However, its EMI shielding performance suffers from the material’s poor elasticity and durability. In this paper, we demonstrate the potential of a self-assembled graphene/polyurethane sponge composite, synthesized via a two-step hydrothermal method, for EMI shielding. This kind of material exhibits a high specific EMI shielding effectiveness of 969–1578 dB cm² g⁻¹ which is comparable or even superior to traditional graphene/polymer sponges. The excellent EMI shielding performance originates from the superconductivity of graphene and the highly porous structure of the graphene/polyurethane sponge. It is found that the polyurethane sponge works as a robust scaffold for graphene to shape its 3D structure. This work introduces a facile yet efficient two-step hydrothermal approach to prepare a graphene/polyurethane sponge with excellent EMI shielding performance and good durability.

Process diagram of PUG Sponge for electromagnetic interference shielding.     

Bilayer graphene/HgCdTe based very long infrared photodetector with superior external quantum efficiency,responsivity, and detectivity

We present a high-performance bilayer graphene (BLG) and mercury cadmium telluride (Hg_1−xCd_x=0.1867Te) heterojunction based very long wavelength infrared (VLWIR) conductive photodetector. The unique absorption properties of graphene enable a long carrier lifetime of charge carriers contributing to the carrier-multiplication due to impact ionization and, hence, large photocurrent and high quantum efficiency. The proposed p⁺-BLG/n-Hg_0.8133Cd_0.1867Te photodetector is characterized and analyzed in terms of different electrical and optical characteristic parameters using computer simulations. The obtained results are further validated by developing an analytical model based on drift-diffusion, tunneling and Chu''s methods. The photodetector has demonstrated a superior performance including improved dark current density (∼1.75 × 10⁻¹⁴ µA cm⁻²), photocurrent density (∼8.33 µA cm⁻²), internal quantum efficiency (QE_int ∼ 99.49%), external quantum efficiency (QE_ext ∼ 89%), internal photocurrent responsivity (∼13.26 A W⁻¹), external photocurrent responsivity (∼9.1 A W⁻¹), noise equivalent power (∼8.3 × 10⁻¹⁸ W), total noise current (∼1.06 fA), signal to noise ratio (∼156.18 dB), 3 dB cut-off frequency (∼36.16 GHz), and response time of 9.4 ps at 77 K. Furthermore, the effects of different external biasing, light power intensity, and temperature are evaluated, suggesting a high QE_ext of 3337.70% with a bias of −0.5 V near room temperature.

We present a high-performance bilayer graphene (BLG) and mercury cadmium telluride (Hg_1−xCd_x=0.1867Te) heterojunction based very long wavelength infrared (VLWIR) conductive photodetector.     

Sustainable rose multiflora derived nitrogen/oxygen-enriched micro-/mesoporous carbon as a low-cost competitive electrode towards high-performance electrochemical supercapacitors

Cost-efficient carbonaceous materials have been utilized extensively for advanced electrochemical supercapacitors. However, modest gravimetric/volumetric capacitances are the insuperable bottleneck in their practical applications. Herein, we develop a simple yet scalable method to fabricate low-cost micro-/mesoporous N/O-enriched carbon (NOC-K) by using natural rose multiflora as a precursor with KOH activation. The biomass-derived NOC-K is endowed with a large surface area of ∼1646.7 m² g⁻¹, micro-/mesoporosity with ∼61.3% microporosity, high surface wettability, and a high content of N (∼1.2 at%)/O (∼26.7 at%) species. When evaluated as an electroactive material for supercapacitors, the NOC-K electrode (5 mg cm⁻²) yields large gravimetric/volumetric specific capacitances of ∼340.0 F g⁻¹ (∼238.0 F cm⁻³) at 0.5 A g⁻¹, and even ∼200.0 F g⁻¹ (∼140.0 F cm⁻³) at 5.0 A g⁻¹, a low capacitance decay of ∼4.2% after 8200 consecutive cycles, and a striking specific energy of ∼8.3 W h kg⁻¹ in aqueous KOH electrolyte, benefiting from its intrinsic structural and compositional superiorities. Moreover, a remarkable specific energy of ∼52.6 W h kg⁻¹ and ∼96.6% capacitance retention over 6500 cycles for the NOC-K based symmetric cell are obtained with the organic electrolyte. More promisingly, the competitive NOC-K demonstrates enormous potential towards advanced supercapacitors both with aqueous and organic electrolytes as a sustainable electrode candidate.

Hierarchical micro-/mesoporous N/O-enriched carbon was scalably fabricated, and exhibited high gravimetric/volumetric capacitances, a large energy density and long-term cycling stability for supercapacitors with aqueous and organic electrolytes.     

Double-layer metal mesh etched by femtosecond laser for high-performance electromagnetic interference shielding window

An excellent transparent electromagnetic interference (EMI) shielding window is proposed and demonstrated theoretically and experimentally. The window is composed of double layers of Au–Ni composite mesh, separated by the quartz-glass substrate. The simulation exhibits that the shielding effectiveness (SE) of the double-layer mesh can be improved by increasing the thickness of the substrate in the low frequency range far below the first interfere valley. The measured SE of the proposed structure reaches over 37.61 dB covering an ultra-wide frequency ranging from 150 MHz to 5 GHz, with a maximal SE of 75.84 dB at 3.58 GHz, while the average optical transmittance of the double-layer mesh maintains ∼76.35% at 400–900 nm. Moreover, femtosecond laser direct writing processing technology is used to manufacture the double-layer metal grids, the fabricated grids are not easy to be scuffed off and has a longer operating life. Such a high-performance EMI shielding window has great potential applications in precision optical monitoring instrument and military devices.

An excellent transparent EMI shielding window is proposed and demonstrated theoretically and experimentally. The results show that the SE reaches over 37.61 dB at 150 MHz to 5 GHz, while the average visible transmittance remains at ∼76.35%.     

Boron/nitrogen co-doped carbon synthesized from waterborne polyurethane and graphene oxide composite for supercapacitors

We report B/N co-doped carbon materials synthesized by an efficient and easy one-step carbonization method with ferric catalyst treatment from a precursor with boric acid treatment after the formation of the composite between waterborne polyurethane (WPU) and graphene oxide (GO). The nitrogen content was improved with the introduction of numerous melamine in the synthetic process of WPU. In addition, WPU possessed a repetitive basic unit urethane bond (–NHCOO); thus, nitrogen heteroatom could be efficiently introduced into the WPU/GO composite from WPU as a nitrogen-rich carbon. In addition, the specific surface area was increased by the boric acid treatment and washing process. The ferric catalyst treatment could prevent the formation of inert B–N bonds. Thus, the synthesized B/N co-doped carbon materials exhibited high specific capacitance (330 F g⁻¹ at 0.5 A g⁻¹), superior rate performance, and excellent cycling stability. Furthermore, the assembled symmetric supercapacitor displayed a good energy density (7.9 W h kg⁻¹ at 505 W kg⁻¹) and a good capacitance retention of about 89.9% after 5000 charge–discharge cycles in 6 M KOH electrolyte. Therefore, the as-prepared B/N co-doped carbon materials show a promising future in supercapacitor application.

We report B/N co-doped carbon materials synthesized by a carbonization method with ferric catalyst treatment from a precursor with boric acid treatment after the formation of the composite between waterborne polyurethane and graphene oxide.     

Sugar based cationic magnetic core–shell silica nanoparticles for nucleic acid extraction

Nucleic acid (NA) extraction is an essential step in molecular testing for a wide range of applications. Conventional extraction protocols usually suffer from time consuming removal of non-nucleic acid impurities. In this study, a new magnetic nanoparticle (MNP) is presented to simplify the NA extraction. A core–shell design, comprising of a ferromagnetic core coated with mesoporous silica, forms the basis of the functional nanoparticle. Chemical functionalization of the silica coating includes a multistep synthesis, in which an activated nanoparticle is coupled with a triethylene glycol spaced glycosyl imidazole. The molecular design aims for charge interactions between the imidazolium-based positive nanoparticle surface and nucleic acids, with specific hydrogen bonding between the surface bonded carbohydrate and nucleic acid targets to ensure nucleic acid selectivity and avoid protein contamination. Two different carbohydrates, differing in molecular size, were selected to compare the efficiency in terms of NA extraction. A triethylene glycol spacer provides sufficient flexibility to remove particle surface constraints for the interaction. The Brunauer–Emmett–Teller (BET) analysis shows a significantly larger surface area for the disaccharide-based particles NpFeSiImMalt (∼181 m² g⁻¹) compared to the monosaccharide analogue NpFeSiImGlc (∼116 m² g⁻¹) at small particles sizes (range ∼ 15 nm) and sufficient magnetization (29 emu g⁻¹) for easy isolation by an external magnetic field. The particles enabled a high DNA particle loading ratio of 30–45 wt% (MNP/DNA ratio), reflecting an efficient extraction process. A high desorption rate (7 min) with more than 86% of unchanged DNA loading was recorded, indicating low damage to the target extract.

New design of cationic magnetic core–shell nanoparticles fabricated with a large hydrophilic group (carbohydrate molecules) enabled high adsorption of a nucleic acid, easy isolation and controlled the movement by applying an external magnetic field.     

Superior quality chemically reduced graphene oxide for high performance EMI shielding materials

The chemical reduction process of graphene oxide combined with a mild and controllable thermal treatment under vacuum at 200 °C for 4 hours provided a cost-effective, scalable, and high-yield route for Reduced Graphene Oxide (RGO) industrial production and became a potential candidate for producing electromagnetic interference (EMI) shielding. We investigated graphite, and RGO using l-ascorbic acid and Sodium borohydride before and after thermal treatment by carefully evaluating the chemical and morphological structures. The thermally treated l-ascorbic Acid reduction route (TCRGOL) conductivity was 2.14 × 10³ S m⁻¹ and total shielding efficiency (SET) based on mass loadings per area of shielding was 94 dB with about one-tenth less graphite weight and surpassing other graphene reduction mechanisms in the frequency range of 8.2–12.4 GHz, i.e., X-band, at room temperature while being tested using the waveguide line technique. The developed treatment represents valuable progress in the path to chemical reduction using a safe reducing agent and offering superior quality RGO rarely achieved with the top-down technique, providing a high EMI shielding performance.

The developed two-step protocol offers a superior reduced graphene oxide TCRGOL quality (7 layers), and its SET was 94 dB over the X-band.     

Boron carbide composites with highly aligned graphene nanoplatelets: light-weight and efficient electromagnetic interference shielding materials at high temperatures

B₄C-based ceramic composites containing 0–2 vol% highly aligned graphene nanoplatelets (GNPs) are fabricated. The electromagnetic interference (EMI) shielding properties of the obtained composites are investigated at X-band (8.2–12.4 GHz) frequency range from room-temperature up to 800 °C. All composites exhibit outstanding EMI shielding properties with satisfactory frequency- and thermal-stability. The shielding effectiveness (SE) of GNP/B₄C composites increases monotonically with increasing GNP loading. Superior room-temperature SE close to 40 dB is achieved with only 2 vol% GNPs and high SE around 35 dB still persists at 800 °C. Considering their relatively low density, GNP/B₄C composites possess a high specific shielding effectiveness (SSE) of 16 dB cm³ g⁻¹ which is among the highest values in reported ceramic-based shielding composites. Especially, the GNP/B₄C composite with 2 vol% GNPs exhibits the highest SSE/t (SSE divided by thickness) values at temperatures above 200 °C for all reported shielding composites, indicating that GNP/B₄C composites belong to the most promising high-temperature shielding composites. The excellent shielding properties of GNP/B₄C composites arise mainly from the high electrical conductivity, high dielectric loss and the multiple reflections by the highly aligned and large-sized GNP layers.

The incorporation of a small amount of highly aligned graphene nanoplatelets into boron carbide leads to light-weight and efficient high-temperature electromagnetic interference shielding composites.     

Ionic magnetic core–shell nanoparticles for DNA extraction

Magnetic nanoparticles with specific surface features are interesting materials for biomedical applications. The combination of molecular interactions on small particles with macroscopic cohesion forces offers unique opportunities. This work reports the synthesis of magnetic core–shell nanoparticles with alkylimidazolium coated surface for effective DNA extraction. A magnetic Fe₂O₃ core was coated with a silica shell and functionalized with an organic halide. This enabled a surface coating with organic cations to mediate effective molecular interactions with polyanionic DNA. The large surface area of the ∼20 nm small particles with a magnetization of 25 emu g⁻¹ enabled high DNA particle loading of 1/30 m% with easy isolation based on an external magnetic field. Moreover, the coating of the particles stabilized DNA against ultrasound initiated fragmentation.

The fabrication ionic magnetic core-shell nanoparticles were simple synthesize with a super-ferromagnetic and small particle size properties, which enabled sufficient DNA particle loading with easy isolation based on an external magnetic field.     

Uniform gallium oxyhydroxide nanorod anodes with superior lithium-ion storage

Exploration of a novel metal oxyhydroxide material provides potential candidates for lithium ion battery (LIB) anodes. In the present work, uniform GaOOH nanorods have been successfully synthesized via a simple hydrothermal method and employed as an anode material for LIBs for the first time. The obtained GaOOH nanorods show a high-purity phase with an average length of ∼1.4 μm and a width of ∼100 nm. As an anode, it delivers a stable capacity of ∼1089 mA h g⁻¹ at a 0.5 A g⁻¹ current density upon 300 cycles and a high rate capacity of ∼639 mA h g⁻¹ at 2 A g⁻¹, where the pseudocapacitance plays a dominant role with a capacity contribution ratio of about 83% at 2.0 mV s⁻¹. This enhanced storage performance can be attributed to a 1D nanostructure with efficient electron and ion transfer as well as strain relaxation upon multiple-cycling.

The hydrothermal GaOOH nanorods with uniform morphology show highly reversible capacity and superior rate performance with boosted pseudocapacitance contribution.     

Structural,optical and photoelectric properties of Mn-doped ZnO films used for ultraviolet detectors

Mn-doped ZnO (MZO) films were prepared on glass substrates using sol–gel dip-coating technology. The microstructural, morphological, optical and photoelectric properties of MZO films were investigated at different withdrawal speeds (WS: 20, 40, 60 and 80 mm s⁻¹). The X-ray diffraction (XRD) patterns showed that all the films obtained were polycrystalline with a hexagonal structure, and the highest crystallinity of MZO films was observed as films were deposited at 40 mm s⁻¹. The UV-Vis spectra revealed that the average optical transmittance of all samples was over 60% and the energy band gap of films decreased from 3.616 to 3.254 eV with the increase in withdrawal speed. The formed Au/MZO/Au photodetectors (PDs) indicate that a device prepared at 40 mm s⁻¹ shows superior properties both in response speed and detection capability, and the rise time is 1.871 s and fall time is 3.309 s at 365 nm for 3 V bias and the detectivity (D*) reaches ∼1.7 × 10¹⁰ Jones. Moreover, the responsivity of PDs is also affected by the distance between Au electrodes and external bias. This research provides a simple way to fabricate the UV PDs based on MZO films with faster response and higher detectivity.

Mn-doped ZnO (MZO) films were prepared on glass substrates using sol–gel dip-coating technology.