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Herein, we report the chemical synthesis of a core–shell nanoarchitecture comprising CuCo2O4@CuO (CCO@CuO) on a flexible stainless steel mesh substrate (FSSM) with CuCo2O4 (core) and CuO (shell) by a simple, cost-efficient, additive-free hydrothermal deposition method, followed by successive ionic layer adsorption and reaction method for fabricating a flexible electrode for an asymmetric supercapacitor (ASC). The nanocomposite of CCO@CuO revealed a high surface area of 98.33 m2 g–1 and the electrode delivered a high specific capacitance of 713 F g–1 at a high current density of 11 mA cm–2, which was noted to be higher than those of the individual constituent CuO (436 F g–1) and CuCo2O4 (443 F g–1) metal oxide electrodes. The CCO@CuO electrode demonstrated remarkable cycling stability (∼90% capacitance retention after 5000 charge–discharge cycles at 15 mA cm–2). The ASC device CCO@CuO//rGO (reduced graphene oxide) delivered a maximum energy density of 37.43 Wh kg–1 at a power density of 250 W kg–1. The device revealed 83% capacitance retention after 4000 cycles. These results indicate that the CCO@CuO/FSSM electrode is a promising functional material for energy storage devices. [ABSTRACT FROM AUTHOR]

The surface of Ti3C2 MXene nanosheets (TC NSs) was first modified with the antioxidants sodium ascorbate (SA) and dopamine (DA) (DSTC NS) to improve their stability in oxidative and hydration environments and thereby improve their bioapplications. This novel approach not only improved MXene stability by arresting oxidation but also increased the available functional groups for further functionalization with various biomolecules. The DSTC NSs were then sequentially conjugated with enzyme glucose oxidase (GOx) and photosensitizer Ce6 to render the obtained CGDSTC NSs with glucose starvation and photodynamic therapeutic properties and thus attain high efficiency in killing cancer cells through the cooperative effect. The as-synthesized CGDSTC NSs demonstrated tremendous photothermal effect with conversion efficiency of 45.1% and photodynamic (ROS generation) properties upon irradiation with 808 and 671 nm lasers. Furthermore, it was observed that the enzymatic activity of CGDSTC NSs increased upon laser irradiation due to enhanced solution temperature. During in vitro studies, the CGDSTC NSs exhibited cytocompatability to HePG2 and HeLa cells under nonstimulus conditions. However, they elicited more than 90% cell-killing efficiency in the presence of glucose and laser irradiation via the cooperative effect between starvation therapy and phototherapy. These results indicate that CGDSTC NSs could be used as potential therapeutic agents to eradicate cancers with no or few adverse effects. This surface modification approach is also simple and facile to adopt in MXene-based research. [ABSTRACT FROM AUTHOR]

Heterostructure engineering offers a powerful approach to creating innovative electrocatalysts. By combining different materials, it can achieve synergistic effects that enhance both charge storage and electrocatalytic activity. In this work, it is capitalized on this concept by designing a 1D/3D CoWO 4 (OH) 2 ·H 2 O/molybdenum disulfide (CTH/MoS 2 ) heterostructure. It is achieved this by in situ depositing 3D MoS 2 nanoflowers on 1D CTH nanorods. To explore the impact of precursor choice, various sulfur (S) sources is investigated. Interestingly, the S precursor influenced the dimensionality of the MoS 2 component. For example, L-cysteine (L-cys), and glutathione (GSH) resulted in 0D morphologies, thiourea (TU) led to a 2D structure, and thioacetamide (TAA) yielded a desirable 3D architecture. Notably, the 1D/3D CTH/MoS 2 -TAA heterostructure exhibited exceptional performance in both supercapacitors (SCs) and quantum dot-sensitized solar cells (QDSSCs). This achievement can be attributed to several factors: the synergetic effect between 1D CTH and 3D MoS 2 , improved accessibility due to the multi-dimensional structure, and a tailored electronic structure facilitated by the Mott-Schottky (M-S) interaction arising from the different material Fermi levels. This interaction further enhances conductivity, ultimately leading to the observed high specific capacity in SCs (154.44 mAh g -1 at 3 mA cm -2 ) and remarkable photovoltaic efficiency in QDSSCs (6.48%)., (© 2024 Wiley‐VCH GmbH.)

In this study, for the first time, red-emitting CsMg x Pb 1- x I 3 quantum dots (QDs) are prepared by doping with magnesium (Mg) ions via the one-pot microwave pyrolysis technique. The X-ray diffraction and X-ray photoelectron spectroscopy results have confirmed partial substitution of Pb 2+ by Mg 2+ inside the CsPbI 3 framework. The as-synthesized CsMg x Pb 1- x I 3 QDs have exhibited excellent morphology, higher quantum yield (upto ∼89%), better photostability and storage stability than undoped CsPbI 3 . Next, the bioavailability of as-synthesized hydrophobic CsMg x Pb 1- x I 3 QDs is improved by encapsulating them into gadolinium-conjugated pluronic 127 (PF127-Gd) micelles through hydrophobic interactions (PQD@Gd). The optical properties of perovskite quantum dots (PQDs) and the presence of Gd could endow the PQD@Gd with fluorescence imaging, magnetic resonance imaging (MRI), and phototherapeutic properties. Accordingly, the MRI contrasting effects of PQD@Gd nanoagents are demonstrated by employing T 1 and T 2 studies, which validated that PQD@Gd nanoagents had superior MR contrasting effect with a r 2 / r 1 ratio of 1.38. In vitro MRI and fluorescence imaging analyses have shown that the PQD@Gd nanoagents are internalized into the cancer cells via a caveolae-mediated endocytosis pathway. The PQD@Gd nanoagents have exhibited excellent biocompatibility even at concentrations as high as 450 ppm. Interestingly, the as-prepared PQD@Gd nanoagents have efficiently produced cytotoxic reactive oxygen species in the cancer cells under 671 nm laser illumination and thereby induced cell death. Moreover, the PQD@Gd nanoagent also demonstrated excellent photocatalytic activity toward organic pollutants under visible light irradiation. The organic pollutants rhodamine b, methyl orange, and methylene blue were degraded by 92.11, 89.21, and 76.21%, respectively, under 60, 80, and 100 min, respectively, irradiation time. The plausible mechanism for the photocatalytic activity is also elucidated. Overall, this work proposes a novel strategy to enhance the optical properties, stability, and bioapplicability of PQDs. The multifunctional PQD@Gd nanoagents developed in this study could be the potential choice of components not only for cancer therapy due to dual-modal imaging and photodynamic therapeutic properties but also for organic pollutant or bacterial removal due to excellent photocatalytic properties.

The implementation of a structure-designed strategy to construct hierarchical architectures of multicomponent metal oxide-based electrode materials for energy storage devices is in the limelight. Herein, we report NiO nanoflakes impregnated on ZnCo 2 O 4 nanorod arrays as ZnCo 2 O 4 @NiO core-shell structures on a flexible stainless-steel mesh substrate, fabricated by a simple, cost-effective and environmentally friendly reflux condensation method. The core-shell structure of ZnCo 2 O 4 @NiO is used as an electrode material in a supercapacitor as it provides a high specific surface area (134.79 m 2 g -1 ) offering high electroactive sites for a redox reaction, reduces the electron and ion diffusion path, and promotes an efficient contact between the electroactive material and electrolyte. The binder-free ZnCo 2 O 4 @NiO electrode delivers a high specific capacitance of 882 F g -1 at 4 mA cm -2 current density and exhibits remarkable cycling stability (∼85% initial capacitance retention after 5000 charge-discharge cycles at 10 mA cm -2 ). The asymmetric supercapacitor device ZnCo 2 O 4 @NiO//rGO delivered a maximum energy density of 46.66 W h kg -1 at a power density of 800 W kg -1 . The device exhibited 90.20% capacitance retention after 4000 cycles. These results indicate that the ZnCo 2 O 4 @NiO architecture electrode is a promising functional material for energy storage devices., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Nanostructured NiCo 2 O 4 is a promising material for energy storage systems. Herein, we report the binder-free deposition of porous marigold micro-flower like NiCo 2 O 4 (PNCO) on the flexible stainless-steel mesh (FSSM) as (PNCO@FSSM) electrode by simple chemical bath deposition. The SEM and EDS analysis revealed the marigold micro-flowers like morphology of NiCo 2 O 4 and its elemental composition. The porous nature of the electrode is supported by the BET surface area (100.47 m 2 g -1 ) and BJH pore size diameter (∼1.8 nm) analysis. This PNCO@FSSM electrode demonstrated a specific capacitance of 530 F g -1 at a high current density of 6 mA cm -2 and revealed 90.5% retention of specific capacitance after 3000 cycles. The asymmetric supercapacitor device NiCo 2 O 4 //rGO within a voltage window of 1.4 V delivered a maximum energy density of 41.66 W h kg -1 at a power density of 3000 W kg -1 . The cyclic stability study of this device revealed 73.33% capacitance retention after 2000 cycles. These results indicate that the porous NiCo 2 O 4 micro-flowers electrode is a promising functional material for the energy storage device., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)