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In recent years, there has been an upsurge in the study of novel and alternative energy storage devices beyond lithium‐based systems due to the exponential increase in price of lithium. Sodium (Na) metal‐based batteries can be a possible alternative to lithium‐based batteries due to the similar electrochemical voltage of Na and Li together with the thousand times higher natural abundance of Na compared to Li. Though two different kinds of Na–O2 batteries have been studied specifically based on electrolytes until now, very recently, a hybrid Na–air cell has shown distinctive advantage over nonaqueous cell systems. Hybrid Na–air batteries provide a fundamental advantage due to the formation of highly soluble discharge product (sodium hydroxide) which leads to low overpotentials for charge and discharge processes, high electrical energy efficiency, and good cyclic stability. Herein, the current status and challenges associated with hybrid Na–air batteries are reported. Also, a brief description of nonaqueous Na–O2 batteries and its close competition with hybrid Na–air batteries are provided. Nonaqueous Na–O2 and hybrid Na–air are two different kinds of sodium metal‐based oxygen batteries. Herein, information about their charge storage mechanism and the fundamental advantage of hybrid Na–air batteries over nonaqueous Na–O2 batteries are provided. Further, the various essential components required and progress in the development of hybrid Na–air batteries are also discussed.

Since their discovery in 2011, transition metal carbides or nitrides (MXenes) have attracted a wide range of attention due to their unique properties and promise for use in a variety of applications. However, the low accessible surface area and poor processability of MXene nanosheets caused by their restacking have severely hindered their practical use, and this is expected to be solved by integrating them into macroscopic assemblies. Here, recent progress in the construction of MXene assemblies from 2D to 3D at the macro and/or microlevel is summarized. The mechanisms of their assembly are also discussed to better understand the relationship between performance and assembled structure. The possible uses of MXene assemblies in energy conversion and storage, electromagnetic interference shielding and absorption, and other applications are summarized. The MXene assemblies are promising for broadening the applications of MXenes and promoting their realization in practice. Herein, the MXene assemblies from 2D to 3D at macro and/or microlevels are reviewed. The corresponding assembly mechanisms and applications are also summarized to better deepen the cognition of relationships between assembled structures and specific applications.

Great and interdisciplinary research efforts have been devoted to the biomedical applications of 2D materials because of their unique planar structure and prominent physiochemical properties. Generally, ceramic‐based biomaterials, fabricated by high‐temperature solid‐phase reactions, are preferred as bone scaffolds in hard tissue engineering because of their controllable biocompatibility and satisfactory mechanical property, but their potential biomedical applications in disease theranostics are paid much less attention, mainly due to their lack of related material functionalities for possibly entering and circulating within the vascular system. The emerging 2D MXenes, a family of ultrathin atomic nanosheet materials derived from MAX phase ceramics, are currently booming as novel inorganic nanosystems for biologic and biomedical applications. The metallic conductivity, hydrophilic nature, and other unique physiochemical performances make it possible for the 2D MXenes to meet the strict requirements of biomedicine. This work introduces the very recent progress and novel paradigms of 2D MXenes for state‐of‐the‐art biomedical applications, focusing on the design/synthesis strategies, therapeutic modalities, diagnostic imaging, biosensing, antimicrobial, and biosafety issues. It is highly expected that the elaborately engineered ultrathin MXenes nanosheets will become one of the most attractive biocompatible inorganic nanoplatforms for multiple and extensive biomedical applications to profit the clinical translation of nanomedicine. Emerging 2D MXenes in nanomedicine highlight the current progress in the design of pristine and functionalized MXenes and their composites, with particular emphasis on their biological and biomedical applications. The advances in 2D MXenes include the use of their intrinsic physiochemical nature, such as controllable in‐plane component, transformable multidimension, and tunable terminating species, which are of multifunctionality, programmability, and biocompatibility.

Recent advances of plasmonic nanoparticles include fascinating developments in the fields of energy, catalyst chemistry, optics, biotechnology, and medicine. The plasmonic photothermal properties of metallic nanoparticles are of enormous interest in biomedical fields because of their strong and tunable optical response and the capability to manipulate the photothermal effect by an external light source. To date, most biomedical applications using photothermal nanoparticles have focused on photothermal therapy; however, to fully realize the potential of these particles for clinical and other applications, the fundamental properties of photothermal nanoparticles need to be better understood and controlled, and the photothermal effect‐based diagnosis, treatment, and theranostics should be thoroughly explored. This Progress Report summarizes recent advances in the understanding and applications of plasmonic photothermal nanoparticles, particularly for sensing, imaging, therapy, and drug delivery, and discusses the future directions of these fields. Photothermally active plasmonic nanoparticles are of great interest in biomedical science due to their tunable resonance wavelength, high spatiotemporal resolution, photothermal therapeutic potential, and remote‐controllability by an external light source. Fundamentals in the design, synthesis, and properties of photothermal nanomaterials and the recent key advances in their biomedical applications, including in biosensors, imaging, therapy, drug delivery, and theranostics, are summarized and discussed.

With the rapid development of nanotechnology, stimuli‐responsive nanomaterials have provided an alternative for designing controllable drug delivery systems due to their spatiotemporally controllable properties. As a new type of porous material, metal–organic frameworks (MOFs) have been widely used in biomedical applications, especially drug delivery systems, owing to their tunable pore size, high surface area and pore volume, and easy surface modification. Here, recent progress in MOF‐based stimuli‐responsive systems is presented, including pH‐, magnetic‐, ion‐, temperature‐, pressure‐, light‐, humidity‐, redox‐, and multiple stimuli‐responsive systems for the delivery of anticancer drugs. The remaining challenges and suggestions for future directions for the rational design of MOF‐based nanomedicines are also discussed. Reaching the advanced drug delivery potential of metal–organic frameworks (MOFs) featuring spatiotemporally controllable properties is of utmost importance. MOFs have the advantages of high drug loading capacities, easy functionalization, and good biocompatibility. The development of MOF‐based stimuli‐responsive drug delivery systems provides a means of designing exciting nanoformulations for clinical translation in future nanomedicines.

In the past few years, soft robotics has rapidly become an emerging research topic, opening new possibilities for addressing real‐world tasks. Perception can enable robots to effectively explore the unknown world, and interact safely with humans and the environment. Among all extero‐ and proprioception modalities, the detection of mechanical cues is vital, as with living beings. A variety of soft sensing technologies are available today, but there is still a gap to effectively utilize them in soft robots for practical applications. Here, the developments in soft robots with mechanical sensing are summarized to provide a comprehensive understanding of the state of the art in this field. Promising sensing technologies for mechanically perceptive soft robots are described, categorized, and their pros and cons are discussed. Strategies for designing soft sensors and criteria to evaluate their performance are outlined from the perspective of soft robotic applications. Challenges and trends in developing multimodal sensors, stretchable conductive materials and electronic interfaces, modeling techniques, and data interpretation for soft robotic sensing are highlighted. The knowledge gap and promising solutions toward perceptive soft robots are discussed and analyzed to provide a perspective in this field. Proprioception and tactile sensing in soft robots are needed for real‐world applications. Various soft sensing technologies that hold promise for inventing sensorized soft robots are available today. However, innovations in robust and high‐performance multimodal sensors, stretchable conductors for electrodes and interconnections, fully integrated and/or wireless electronic interfaces, modeling, and data interpretation methods are highly demanded.

The rapid, highly sensitive, and accurate detection of bacteria is the focus of various fields, especially food safety and public health. Surface‐enhanced Raman spectroscopy (SERS), with the advantages of being fast, sensitive, and nondestructive, can be used to directly obtain molecular fingerprint information, as well as for the on‐line qualitative analysis of multicomponent samples. It has therefore become an effective technique for bacterial detection. Within this progress report, advances in the detection of bacteria using SERS and other compatible techniques are discussed in order to summarize its development in recent years. First, the enhancement principle and mechanism of SERS technology are briefly overviewed. The second part is devoted to a label‐free strategy for the detection of bacterial cells and bacterial metabolites. In this section, important considerations that must be made to improve bacterial SERS signals are discussed. Then, the label‐based SERS strategy involves the design strategy of SERS tags, the immunomagnetic separation of SERS tags, and the capture of bacteria from solution and dye‐labeled SERS primers. In the third part, several novel SERS compatible technologies and applications in clinical and food safety are introduced. In the final part, the results achieved are summarized and future perspectives are proposed. This progress report focuses on the progress for bacterial detection by surface‐enhanced Raman spectroscopy (SERS) and other compatible techniques, and the contents mainly include the following parts: the enhancement principle and mechanism of SERS, the progress of label‐free strategy and label‐based strategy for SERS detection of bacteria, several novel developed SERS compatible technologies and the application in clinical and food safety.

Surface‐enhanced Raman scattering (SERS) spectroscopy provides a noninvasive and highly sensitive route for fingerprint and label‐free detection of a wide range of molecules. Recently, flexible SERS has attracted increasingly tremendous research interest due to its unique advantages compared to rigid substrate‐based SERS. Here, the latest advances in flexible substrate‐based SERS diagnostic devices are investigated in‐depth. First, the intriguing prospect of point‐of‐care diagnostics is briefly described, followed by an introduction to the cutting‐edge SERS technique. Then, the focus is moved from conventional rigid substrate‐based SERS to the emerging flexible SERS technique. The main part of this report highlights the recent three categories of flexible SERS substrates, including actively tunable SERS, swab‐sampling strategy, and the in situ SERS detection approach. Furthermore, other promising means of flexible SERS are also introduced. The flexible SERS substrates with low‐cost, batch‐fabrication, and easy‐to‐operate characteristics can be integrated into portable Raman spectroscopes for point‐of‐care diagnostics, which are conceivable to penetrate global markets and households as next‐generation wearable sensors in the near future. Flexible surface‐enhanced Raman scattering (SERS) sensors have attracted great research attention owing to their distinct superiorities that the traditional rigid SERS substrates are not accessible to. Recent innovative strategies in developing flexible SERS sensors based on actively tunable plasmonic resonance, swab‐sampling route, and the in situ detection approach are highlighted, which affords unprecedented opportunities to realize point‐of‐care diagnostics in diverse applications.

To identify the intrinsic active sites in oxides or oxide supported catalysts is a research frontier in the fields of heterogeneous catalysis and material science. In particular, the role of oxygen vacancies on the redox properties of oxide catalysts is still not fully understood. Herein, some relevant research dealing with M1–O–M2 or M1–□–M2 linkages as active sites in mixed oxides, in oxide supported single‐atom catalysts, and at metal/oxide interfaces of oxide supported nanometal catalysts for various reaction systems is reviewed. It is found that the catalytic activity of these oxides not only depends on the amounts of oxygen vacancies and metastable cations but also shows a significant influence from the local environment of the active sites, in particular, the symmetry of the oxygen vacancies. Based on the recent progress in the relevant fields, an “asymmetric oxygen vacancy site” is introduced, which indicates an oxygen vacancy with an asymmetric coordination of cations, making oxygen “easy come, easy go,” i.e., more reactive in redox reactions. The establishment of this new mechanism would shed light on the future investigation of the intrinsic active sites in oxide and oxide supported catalysts. Asymmetric oxygen vacancies in metal oxide catalysts act as intrinsic catalytic active sites for redox reactions by making oxygen species easy come, easy go. Some relevant work focused on the active sites with asymmetric bonding situations in doped oxides, in oxide stabilized single‐atom catalysts, and at metal/oxide interface is reviewed.

Electrocatalytic water splitting (2H2O → 2H2 + O2) is a very promising avenue to effectively and environmentally friendly produce highly pure hydrogen (H2) and oxygen (O2) at a large scale. Different materials have been developed to enhance the efficiency for water splitting. Among them, chalcogenides with unique atomic arrangement and high electronic transport show interesting catalytic properties in various electrochemical reactions, such as the hydrogen evolution reaction, oxygen evolution reaction, and overall water splitting, while the control of their morphology and structure is of vital importance to their catalytic performance. Herein, the general synthetic methods are summarized to prepare metal chalcogenides and different strategies are designed to improve their catalytic performance for water splitting. The remaining challenges in the research and development of metal chalcogenides and possible directions for future research are also summarized. Herein, the general synthetic methods and different strategies for preparing metal chalcogenides are summarized to improve their catalytic performance in the hydrogen evolution reaction and oxygen evolution reaction. The challenges of built metal chalcogenides catalysts are summarized to enhance and develop future promising applications.