Nanoscience is a booming field incorporating some of the most fundamental questions concerning structure, function, and applications. The cutting-edge research in nanoscience requires access to advanced techniques and instrumentation capable of approaching these unanswered questions. Over the past few decades, atomic force microscopy (AFM) has been developed as a powerful platform, which enables in situ characterization of topological structures, local physical properties, and even manipulating samples at nanometer scale. Currently, an imaging mode called PeakForce Tapping (PFT) has attracted more and more attention due to its advantages of nondestructive characterization, high-resolution imaging, and concurrent quantitative property mapping. In this review, the origin, principle, and advantages of PFT on nanoscience are introduced in detail. Three typical applications of this technique, including high-resolution imaging of soft samples in liquid environment, quantitative nanomechanical property mapping, and electrical/electrochemical property measurement will be reviewed comprehensively. The future trends of PFT technique development will be discussed as well.

Supercapacitor has gained significant attention due to its fast charging/discharging speed, high power density and long-term cycling stability in contrast to traditional batteries. In this review, state-of-the-art achievements on supercapacitor electrode based on carbon materials is summarized. In all-carbon composite materials part, various carbon materials including graphene, carbon nanotube, carbon foam and carbon cloth are composited to fabricate larger specific surface area and higher electrical conductivity electrodes. However, obstacles of low power density as well as low cycling life still remain to be addressed. In metal-oxide composites part, carbon nanotube, graphene, carbon fiber fabric and hollow carbon nanofibers combine with MnO₂respectively, which significantly address drawbacks of all-carbon material electrodes. Additionally, TiO₂is incorporated into graphene electrode to overcome the low mechanical flexibility of graphene. In organic active compounds part, conducting polymers are employed to combinate with carbon materials to fabricate high specific capacitance, long-term thermal stability and outstanding electroconductivity flexible textile supercapacitors. In each part, innovation, fabrication process and performance of the resulting composites are demonstrated. Finally, future directions that could enhance the performance of supercapacitors are discussed.

This paper demonstrates a brief review of the research progress of the advanced carbon-based materials for the supercapacitor electrodes. Diverse types of carbon-based electrodes exploited and reported to the literature are summarized and classified into pure carbon electrodes, carbon/metal oxides composite electrodes, carbon/metal oxides/conducting polymers composite electrodes as well as carbon electrodes based on other materials. Pure carbon electrodes are firstly introduced, confirming their merits and shortcomings. To cover the shortage of pure carbon electrodes and further enhances their electrochemical performance, a composite electrode, combined with metal oxides and conducting polymers, is respectively presented. It is worth noticing in this article that combining various materials to form composites has been one main direction to own a positive synergistic effect on the carbon-based electrodes.

Nanomaterials-based gas sensors have great potential for substance detection. This paper first outlines the research of gas sensors composed of various dimensional nanomaterials. Secondly, nanomaterials may become the development direction of a new generation of gas sensors due to their high sensing efficiency, good detection capability and high sensitivity. Through their excellent characteristics, gas sensors also show high responsiveness and sensing ability, which also plays an increasingly important role in the field of electronic skin. We also reviewed the physical sensors formed from nanomaterials in terms of the methods used, the characteristics of each type of sensor, and the advantages and contributions of each study. According to the different kinds of signals they sense, we especially reviewed research on gas sensors composed of different nanomaterials. We also reviewed the different mechanisms, research processes, and advantages of the different ways of constituting gas sensors after sensing signals. According to the techniques used in each study, we reviewed the differences and advantages between traditional and modern methods in detail. We compared and analyzed the main characteristics of gas sensors with various dimensions of nanomaterials. Finally, we summarized and proposed the development direction of gas sensors based on various dimensions of nanomaterials.

Perovskite solar cells (PSCs) are set to be game changing components in next-generation photovoltaic technology due to their high efficiency and low cost. In this article, recent progress in the development of perovskite layers, which are the basis of PSCs, is reviewed. Achievements in the fabrication of high-quality perovskite films by various methods and techniques are introduced. The reported works demonstrate that the power conversion efficiency of the perovskite layers depends largely on their morphology and the crystalline quality. Furthermore, recent achievements concerning the scalability of perovskite films are presented. These developments aim at manufacturing large-scale perovskite solar modules at high speed. Moreover, it is shown that the development of low-dimensional perovskites plays an important role in improving the long-term ambient stability of PSCs. Finally, these latest advancements can enhance the competitiveness of PSCs in photovoltaics, paving the way for their commercialization. In the closing section of this review, some future critical challenges are outlined, and the prospect of commercialization of PSCs is presented.