The corrosion, passivation, and dendritic growth of Zn anodes and the dissolution of cathodes hinder rechargeable aqueous zinc ion battery (AZIB) rejuvenation. In this work, a versatile Zn‐based montmorillonite (MMT) interlayer is constructed to achieve a stable rechargeable AZIB. The Zn‐based MMT coating Zn foil (MMT‐Zn) is designed to enable a high transference number for Zn2+ (t+ ≈ 0.82) and a freeway for Zn2+ migration to alleviate corrosion and passivation and suppress Zn dendrites. The results show the MMT‐Zn symmetrical batteries render dendrite‐free plating/stripping with an ultra‐stable and small overpotential (50 mV) and a long‐life span (1000 cycles) at 1 mA cm−2/0.25 mAh cm−2 and with 100 mV overpotential at ultrahigh current and capacity of 10 mA cm−2/45 mAh cm−2 (over 1000 h, 77% depth of discharge). The MMT interlayer is applied to the MnO2 cathode to inhibit the discharge product dissolving and diffusing into the electrolyte, so that the stability of the capacity is maintained. Thus, MMT‐Zn||MMT‐MnO2 delivers an ultra‐long cycle life and ultra‐high capacity (1100 cycles with 191.5 mAh g−1 at 2 C). Hopefully, Zn‐based MMT interlayer can be considered to improve the electrochemical performance of the metal anodes and soluble cathodes.
The sensing of bioactive molecules based on photochemical techniques has become one of the fastest-growing scientific fields. Surface-enhanced Raman scattering (SERS) is a highly sensitive technique for the detection of low-concentration molecules, including DNA, microRNA, proteins, blood, and bacteria; single-cell detection and identification; bioimaging; and disease diagnosis, providing abundant structural information for biological analytes. One rapidly developing field of SERS biosensor design is the use of carbon-based nanomaterials as substrate materials, such as zero-dimensional carbon quantum dots, one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide (GO) and three-dimensional spatial carbon nanomaterials or carbon-based core-shell nanostructures. In this review, we describe the recent developments in SERS biosensors, in particular carbon-based SERS, for the detection of bioactive molecules. We systematically survey recent developments in carbon nanomaterial-based SERS biosensors, focusing on fundamental principles for carbon-based materials for SERS biosensor design, fabrication, and operation, and provide insights into their rapidly growing future potential in the fields of biomedical and biological engineering, in situ analysis, quantitative analysis, and flexible photoelectric functional materials. As such, this review can play the role of a roadmap to guide researchers toward concepts that can be used in the design of next-generation SERS biosensors while also highlighting current advancements in this field.
Electromagnetic fields with complex spatial variation routinely arise in Nature. We study the response of a small molecule to monochromatic fields of arbitrary three-dimensional geometry. First, we consider the allowed configurations of the fields and field gradients at a single point in space. Many configurations cannot be generated from a single plane wave, regardless of polarization, but any allowed configuration can be generated by superposition of multiple plane waves. There is no local configuration of the fields and gradients that requires near-field effects. Second, we derive a set of local electromagnetic quantities, each of which couples to a particular multipole transition. These quantities are small or zero in plane waves, but can be large in regions of certain superpositions of plane waves. Our findings provide a systematic framework for designing far-field and near-field experiments to drive multipole transitions. The proposed experiments provide information on molecular structure that is inaccessible to other spectroscopic techniques and open the possibility for new types of optical control of molecules.
Much attention is paid to metal lithium as a hopeful negative material for reversible batteries with a high specific capacity. Although applying 3D hosts can relieve the dendrite growth to some extent, gradient‐distributed lithium ion in 3D uniform hosts still induces uncontrolled lithium dendrites growth, especially at high lithium capacity and high current density. Herein, a 3D conductive carbon nanofiber framework with gradient‐distributed ZnO particles as nucleation seeds (G‐CNF) to regulate lithium deposition is proposed. Based on such a unique structure, the G‐CNF electrode exhibits a high average Coulombic efficiency (CE) of 98.1% for 700 cycles at 0.5 mA cm−2. Even at 5 mA cm−2, the G‐CNF electrode performs a stable cycling process and high CE of 96.0% for over 200 cycles. When the lithium‐deposited G‐CNF (G‐CNF‐Li) anode is applied in a full cell with a commercial LiFePO4 cathode, it exhibits a stable capacity of 115 mAh g−1 and high retention of 95.7% after 300 cycles. Through inducing the gradient‐distributed nucleation seeds to counter the existing Li‐ion concentration polarization, a uniform and stable lithium deposition process in the 3D host is achieved even under the condition of high current density.
Inorganic photocatalyst−enzyme systems are a prominent platform for the photoreduction of CO 2 to valueadded chemicals and fuels. However, poor electron transfer kinetics and enzyme deactivation by reactive oxygen species in the photoexcitation process severely limit catalytic efficiency. In chloroplast, enzymatic CO 2 reduction and photoexcitation are compartmentalized by the thylakoid membrane, which protects enzymes from photodamage, while the tightly integrated photosystem facilitates electron transfer, promoting photocatalysis. By mimicking this strategy, we constructed a novel functionally compartmental inorganic photocatalyst−enzyme system for CO 2 reduction to formate. To accomplish efficient electron transfer, we first synthesized an integrated artificial photosystem by conjugation of the cocatalyst (a Rh complex) onto thiophene-modified C 3 N 4 (TPE-C 3 N 4 ), demonstrating an NADH regeneration rate of 9.33 μM•min −1 , 2.33 times higher than that of a homogeneous counterpart. The enhanced NADH regeneration activity was caused by the tightly conjugated structure of the artificial photosystem, enabling rapid electron transfer from TPE-C 3 N 4 to the Rh complex. To protect formate dehydrogenase (FDH) from photoinduced deactivation, FDH was encapsulated into MAF-7, a metal−organic framework (MOF) material, to compartmentalize FDH from the toxic photoexcitation process, similar to the function of the thylakoid membrane. Moreover, the triazole linkers of MAF-7 possess both hydrophilicity and pH-buffering capacity providing a stable microenvironment for FDH, which could enhance enzyme stability in photosynthesis. The synergy between the enhanced electron transfer of TPE-C 3 N 4 for NADH cofactor regeneration and MOFprotection of the redox enzyme enables the construction of a functionally compartmental inorganic photocatalyst−enzyme association system, promoting CO 2 photoconversion to formic acid with a yield of 16.75 mM after 9 h of illumination, 3.24 times greater than that of the homogeneous reaction counterpart.
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